Journal articles on the topic 'Nanoparticle'
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1
Wang, Cheng, Hong Lin, and Yu Yue Chen. "Study on the Preparation of Steady-State Chitosan Nanoparticle as Silk-Fabric Finishing Agent." Advanced Materials Research 175-176 (January 2011): 745–49. http://dx.doi.org/10.4028/www.scientific.net/amr.175-176.745.
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The chitosan nanoparticles can be prepared by ionotropic gelation method in dispersion system. Chitosan nanoparticle has advantages of both the chitosan and the nano particles, and so it has a wide application in the textile finishing field. In this paper, the effects of the concentration of TPP, Span-80, deposited time and pH value on the diameter distribution of the chitosan nanoparticles are discussed in order to obtain the optimized preparation technics of steady state chitosan nanoparticle. The results show that chitosan nanoparticles are successfully prepared by ionotropic gelation method. Under the optimized preparation technics, chitosan nanoparticles disperse homogeneously in the system and have a good steady state. The average diameter of chitosan nanoparticle in the dispersion system is 20.82nm. Compared with the ordinary silk fabric, the B. mori silk fabric treated with chitosan nanoparticle dispersion system has better deepen effect of reactive dyes. The chitosan nanopartilce dispersion system is helpful to improve the dye uptake and dye fixation of silk fabrics.
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Li, Meng, Liqiang Lin, Ruyan Guo, Amar Bhalla, and Xiaowei Zeng. "Numerical investigation of size effects on mechanical behaviors of Fe nanoparticles through an atomistic field theory." Journal of Micromechanics and Molecular Physics 02, no. 03 (September 2017): 1750010. http://dx.doi.org/10.1142/s2424913017500102.
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At nanoscale, the mechanical response of nanoparticles is largely affected by the particle size. To assess the effects of nanoparticle size (e.g., nanoparticle’s volume, cross-sectional area and length) on mechanical behaviors of bcc Fe nanoparticles under compressive loading, an atomistic field theory was introduced in current study. In the theory, atomistic definitions and continuous local density functions of fundamental physical quantities were derived. Through the atomistic potential-based method, the mechanical responses of bcc Fe nanoparticles were analyzed in different sizes. The simulation results reveal that the ultimate stress decreases as Fe nanoparticle’s volume, cross-sectional area or length increases under compressive loading. Nonetheless, the Young’s modulus increases as nanoparticle size increases. In addition, for a fixed finite volume nanoparticle, this study indicates that the ultimate stress will increase as strain rate increases, but Young’s modulus will decrease with increasing strain rate. A loading–unloading study illustrates the energy dissipation due to irreversible structure changes in Fe nanoparticles.
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Karatrantos, Argyrios, Yao Koutsawa, Philippe Dubois, Nigel Clarke, and Martin Kröger. "Miscibility and Nanoparticle Diffusion in Ionic Nanocomposites." Polymers 10, no. 9 (September 10, 2018): 1010. http://dx.doi.org/10.3390/polym10091010.
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We investigate the effect of various spherical nanoparticles in a polymer matrix on dispersion, chain dimensions and entanglements for ionic nanocomposites at dilute and high nanoparticle loading by means of molecular dynamics simulations. The nanoparticle dispersion can be achieved in oligomer matrices due to the presence of electrostatic interactions. We show that the overall configuration of ionic oligomer chains, as characterized by their radii of gyration, can be perturbed at dilute nanoparticle loading by the presence of charged nanoparticles. In addition, the nanoparticle’s diffusivity is reduced due to the electrostatic interactions, in comparison to conventional nanocomposites where the electrostatic interaction is absent. The charged nanoparticles are found to move by a hopping mechanism.
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Ningrum, Wulan Agustin, W. Wirasti, Yulian Wahyu Permadi, and Fida Faiqatul Himmah. "Uji Sediaan Lotion Nanopartikel Ekstrak Terong Belanda Sebagai Antioksidan." Jurnal Ilmiah Kesehatan 14, no. 1 (March 29, 2021): 99. http://dx.doi.org/10.48144/jiks.v14i1.539.
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Abstrak. Nanopartikel adalah suatu teknologi formulasi suatu partikel yang terdispersi pada ukuran nanometer atau skala per seribu mikron. Tujuan penelitian ini adalah membuat sediaan lotion dari nanopartikel ekstrak terong belanda sebagai antioksidan. Teknologi nanopartikel ekstrak terong belanda mempunyai efek yang sangat baik sebagai antioksidan, sehingga dimungkinkan dibuat sediaan sebagai bahan kosmetik Penelitian ini menguji nanopertikel ekstrak terong belanda sebagai antioksidan sediaan lotion. Metode ekstraksi yang digunakan dalam penelitian ini adalah maserasi menggunakan pelarut metanol. Pembuatan teknologi nanopartikel ekstrak terong belanda menggunakan metode nanopertikel berbasis biopolimer. Nanopartikel ekstrak terong belanda diformulasi menjadi sediaan lotion. Uji aktivitas antioksidan dilakukan dengan metode penangkap radikal bebas DPPH. Parameter aktivitas antioksidan yaitu IC50 (Inhibititon Concentration), sedangkan uji sediaan lotion terdiri dari pH, viskositas, stabilitas, organoleptis (warna, aroma, bentuk). Hasil dari penelitian menunjukkan Lotion ekstrak terong belanda yang dihasilkan memenuhi syarat evaluasi fisik sediaan. Nilai IC50 lotion nanopartikel ekstrak terong belanda adalah 62 µg/mL. Ukuran partikel dari ekstrak nanopartikel adalah 182,4 µm. Lotion nanopartikel ekstrak terong belanda mempunyai kestabilan yang baik. Perlu dilakukan pembuatan bentuk sediaan yang lain dengan tujuan sebagai kosmetika.
Kata kunci : Ekstrak terong belanda, nanopartikel, lotion, IC50
Tamarillo Extract Nanoparticle Lotion Preparation Test As Antioxidant
Abstract. Nanoparticles are a technology for the formulation of particles that are dispersed at the nanometer size or scale per thousand microns. The purpose of this study was to make lotion preparations from the nanoparticles of tamarillo extract as an antioxidant. The nanoparticle technology of tamarillo extract has a very good effect as an antioxidant, so it is possible to make a cosmetic ingredient. This study tested the nanoparticle extract of tamarillo as an antioxidant for lotion preparations. The extraction method used in this research is maceration using methanol as a solvent. The manufacture of tamarillo extract nanoparticle technology used a biopolymer-based nanoperticle method. The nanoparticles of tamarillo extract were formulated into lotions. The antioxidant activity test was carried out using the DPPH free radical scavenger method. The parameter of antioxidant activity is IC50 (Inhibititon Concentration), while the lotion preparation test consists of pH, viscosity, stability, organoleptic (color, aroma, shape). The results showed that the tamarillo extract lotion produced met the requirements for the physical evaluation of the preparation. The IC50 value of tamarillo extract nanoparticle lotion was 62 µg / mL. The particle size of the nanoparticle extract was 182.4 µm. Tamarillo extract nanoparticle lotion has good stability. It is necessary to make other dosage forms for the purpose of cosmetics.
Keywords: Tamarillo extract, nanoparticle, lotion, IC50
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Shannahan, Jonathan. "The biocorona: a challenge for the biomedical application of nanoparticles." Nanotechnology Reviews 6, no. 4 (August 28, 2017): 345–53. http://dx.doi.org/10.1515/ntrev-2016-0098.
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AbstractFormation of the biocorona on the surface of nanoparticles is a significant obstacle for the development of safe and effective nanotechnologies, especially for nanoparticles with biomedical applications. Following introduction into a biological environment, nanoparticles are rapidly coated with biomolecules resulting in formation of the nanoparticle-biocorona. The addition of these biomolecules alters the nanoparticle’s physicochemical characteristics, functionality, biodistribution, and toxicity. To synthesize effective nanotherapeutics and to more fully understand possible toxicity following human exposures, it is necessary to elucidate these interactions between the nanoparticle and the biological media resulting in biocorona formation. A thorough understanding of the mechanisms by which the addition of the biocorona governs nanoparticle-cell interactions is also required. Through elucidating the formation and the biological impact of the biocorona, the field of nanotechnology can reach its full potential. This understanding of the biocorona will ultimately allow for more effective laboratory screening of nanoparticles and enhanced biomedical applications. The importance of the nanoparticle-biocorona has been appreciated for a decade; however, there remain numerous future directions for research which are necessary for study. This perspectives article will summarize the unique challenges presented by the nanoparticle-biocorona and avenues of future needed investigation.
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Mohammed, Tawfik Mahmood. "Mathematical modeling of the electronic structure of Titanium dioxide \((TiO_2 )_6\) nanoparticles." University of Aden Journal of Natural and Applied Sciences 24, no. 2 (March 22, 2022): 519–26. http://dx.doi.org/10.47372/uajnas.2020.n2.a19.
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The calculation of the number of atoms of the given dimensional nanoparticle, composed of different type atoms has been researched in this work. The calculations have been carried out for nanoparticles of titanium dioxide. Theoretical visual models have been configured, and quantum – mechanical calculations have been carried out for \((TiO_2 )_6\) nanoparticle. The calculations for titanium dioxide nanoparticle have been carried out on the basis of Gaussian atomic orbitals. Besides, Gaussian functions have been used as atomic orbitals. The numerical values of unknown coefficients of the linear combination of atomic orbitals of the atoms of the titanium nanoparticle have been found from the solution of Hartree–Fock–Roothaan (HFR) equations.The values of orbital energies, ionization potential, and the total electronic energy of titanium dioxide nanoparticles have been determined. The calculations show that ,titanium dioxide nanoparticle is tough, electrophile, and stable dielectric, material. The effective charge of atoms have been calculated, and the theoretical visual mode of titanium dioxide nanopartical have been constructed.
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Wang, Shenqing, Xiliang Yan, Gaoxing Su, and Bing Yan. "Cytotoxicity Induction by the Oxidative Reactivity of Nanoparticles Revealed by a Combinatorial GNP Library with Diverse Redox Properties." Molecules 26, no. 12 (June 14, 2021): 3630. http://dx.doi.org/10.3390/molecules26123630.
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It is crucial to establish relationship between nanoparticle structures (or properties) and nanotoxicity. Previous investigations have shown that a nanoparticle’s size, shape, surface and core materials all impact its toxicity. However, the relationship between the redox property of nanoparticles and their toxicity has not been established when all other nanoparticle properties are identical. Here, by synthesizing an 80-membered combinatorial gold nanoparticle (GNP) library with diverse redox properties, we systematically explored this causal relationship. The compelling results revealed that the oxidative reactivity of GNPs, rather than their other physicochemical properties, directly caused cytotoxicity via induction of cellular oxidative stress. Our results show that the redox diversity of nanoparticles is regulated by GNPs modified with redox reactive ligands.
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Zhang, Yong, Xiao Jing Zhao, Qiang He, Ye Jun, and Qin Po Niu. "Experimental Study of Nanoparticle as Oil Additives." Advanced Materials Research 230-232 (May 2011): 288–92. http://dx.doi.org/10.4028/www.scientific.net/amr.230-232.288.
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Cu nanoparticles as N32 base oil additives were studied in the paper. The structure of Cu nanoparticlcs was characterized by Transmission Electron Microscopy (TEM) and X-ray powder diffraction spectroscope (XRD). The widely used steel-steel friction system was chosen to test the feasibility and practicality of Cu nanoparticles as bearing lubricant additives. The results show that N32 base oil with 0.5% Cu nanoparticle can improve the test sample contact fatigue life than pure N32 base oil.
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Wang, Xijun. "The Magnetic Nanoparticle Movement in Magnetic Fluid Characterized by the Laser Dynamic Speckle Interferometry." Journal of Nanomaterials 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/287813.
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A dual scanning laser speckle interferometry experiment was designed to observe the dynamic behavior of the magnetic fluid actuated by a magnetic field. In order to improve the spatial resolution of the dynamic speckle measurement, the phase delay scanning was used to compensate the additional phase variation which was caused by the transverse scanning. The correlation coefficients corresponding to the temporal dynamic speckle patterns within the same time interval scattering from the nanoparticles were calculated in the experiment on nanoscale magnetic clusters. In the experiment, the speckle of the magnetic nanoparticle fluid movement has been recorded by the lens unmounted CCD within the interferometry strips, although the speckle led to the distinguished annihilation of the light coherence. The results have showed that the nanoparticle fluid dynamic properties appeared synergistically in the fringe speckles. The analyses of the nanoparticle's relative speed and the speckle pattern moving amount in the fringes have proved the nanoparticle’s movement in a laminar flow in the experiment.
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Bao, Lingling, Chaoyang Zhong, Pengfei Jie, and Yan Hou. "The effect of nanoparticle size and nanoparticle aggregation on the flow characteristics of nanofluids by molecular dynamics simulation." Advances in Mechanical Engineering 11, no. 11 (November 2019): 168781401988948. http://dx.doi.org/10.1177/1687814019889486.
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Molecular dynamics simulation is used to investigate the flow characteristics of Cu–Ar nanofluids considering the influence of nanoparticle size and nanoparticle aggregation. Nanofluids viscosity is calculated by equilibrium molecular dynamics based on Green–Kubo equation. Results demonstrate that the viscosity of nanofluids decreases with the increase of nanoparticle size. In addition, nanoparticle aggregation results in the increase of the nanofluids viscosity. Compared with nanoparticle size, nanoparticle aggregation has a larger impact on viscosity. Nanofluids flowing in parallel-plate nanochannels are simulated. The velocity profiles are studied through three nanoparticle sizes (11.55, 14.55, and 18.33 Å) and four nanoparticle aggregate configurations. Results show that the velocity profile of 14.55 Å nanoparticle size is larger than that of other two nanoparticle sizes. As for four nanoparticles, the nanoparticles clustering as a line leads to the maximum velocity profile, while the nanoparticles clustering as a cube causes the minimum velocity profile. Compared with viscosity, nanoparticle aggregation has a greater effect on the velocity profile. When the nanoparticles are evenly distributed, the influence of viscosity on velocity profiles is dominant. Otherwise, the aggregation, aggregate configuration, and distribution of nanoparticles have a dominant impact on the flow characteristics of nanofluids.
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Albarki, Mohammed A., and Maureen D. Donovan. "Uptake of Cationic PAMAM-PLGA Nanoparticles by the Nasal Mucosa." Scientia Pharmaceutica 90, no. 4 (November 25, 2022): 72. http://dx.doi.org/10.3390/scipharm90040072.
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Nanoparticles provide promising advantages in advanced delivery systems for enhanced drug delivery and targeting. The use of a biodegradable polymer such as PLGA (poly lactic-co-glycolic acid) promotes improved nanoparticle safety and, to some extent, provides the ability to modify nanoparticle surface properties. This study compared the effect of altering the surface charge on the translocation of PLGA nanoparticles across excised nasal mucosal tissues. Nanoparticles (average diameter of 60–100 nm) loaded with Nile Red (lipophilic fluorescent dye) were fabricated using a nanoprecipitation method. The effects of nanoparticle surface charge were investigated by comparing the transfer of untreated nanoparticles (negatively charged) and positively charged PLGA nanoparticles, which were modified using PAMAM dendrimer (polyamidoamine, 5th generation). All nanoparticles were able to be transferred in measurable quantities into both nasal respiratory and olfactory mucosae within 30 min. The total nanoparticle uptake was less than 5% of the nanoparticle mass exposed to the tissue surface. The cationic nanoparticles showed a significantly lower transfer into the mucosal tissues where the amount of nanoparticles transferred was 1.8–4-fold lower compared to the untreated negatively charged nanoparticles. The modification of the nanoparticle surface charge can alter the nanoparticle interaction with the nasal epithelial surface, which can result in decreasing the nanoparticle transfer into the nasal mucosa.
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Li, Shidong, Yeap Hung Ng, Hon Chung Lau, Ole Torsæter, and Ludger P. Stubbs. "Experimental Investigation of Stability of Silica Nanoparticles at Reservoir Conditions for Enhanced Oil-Recovery Applications." Nanomaterials 10, no. 8 (August 4, 2020): 1522. http://dx.doi.org/10.3390/nano10081522.
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To be effective enhanced oil-recovery (EOR) agents, nanoparticles must be stable and be transported through a reservoir. However, the stability of a nanoparticle suspension at reservoir salinity and temperature is still a challenge and how it is affected by reservoir rocks and crude oils is not well understood. In this work, for the first time, the effect of several nanoparticle treatment approaches on the stability of silica nanoparticles at reservoir conditions (in the presence of reservoir rock and crude oil) was investigated for EOR applications. The stability of nanoparticle suspensions was screened in test tubes at 70 °C and 3.8 wt. % NaCl in the presence of reservoir rock and crude oil. Fumed silica nanoparticles in suspension with hydrochloric acid (HCl), polymer-modified fumed nanoparticles and amide-functionalized silica colloidal nanoparticles were studied. The size and pH of nanoparticle suspension in contact with rock samples were measured to determine the mechanism for stabilization or destabilization of nanoparticles. A turbidity scanner was used to quantify the stability of the nanoparticle suspension. Results showed that both HCl and polymer surface modification can improve nanoparticle stability under synthetic seawater salinity and 70 °C. Suspensions of polymer-modified nanoparticles were stable for months. It was found that pH is a key parameter influencing nanoparticle stability. Rock samples containing carbonate minerals destabilized unmodified nanoparticles. Crude oil had limited effect on nanoparticle stability. Some components of crude oil migrated into the aqueous phase consisting of amide-functionalized silica colloidal nanoparticles suspension. Nanoparticles modification or/and stabilizer are necessary for nanoparticle EOR application.
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Yang, Wen, Lin Wang, Evan M. Mettenbrink, Paul L. DeAngelis, and Stefan Wilhelm. "Nanoparticle Toxicology." Annual Review of Pharmacology and Toxicology 61, no. 1 (January 6, 2021): 269–89. http://dx.doi.org/10.1146/annurev-pharmtox-032320-110338.
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Nanoparticles from natural and anthropogenic sources are abundant in the environment, thus human exposure to nanoparticles is inevitable. Due to this constant exposure, it is critically important to understand the potential acute and chronic adverse effects that nanoparticles may cause to humans. In this review, we explore and highlight the current state of nanotoxicology research with a focus on mechanistic understanding of nanoparticle toxicity at organ, tissue, cell, and biomolecular levels. We discuss nanotoxicity mechanisms, including generation of reactive oxygen species, nanoparticle disintegration, modulation of cell signaling pathways, protein corona formation, and poly(ethylene glycol)-mediated immunogenicity. We conclude with a perspective on potential approaches to advance current understanding of nanoparticle toxicity. Such improved understanding may lead to mitigation strategies that could enable safe application of nanoparticles in humans. Advances in nanotoxicity research will ultimately inform efforts to establish standardized regulatory frameworks with the goal of fully exploiting the potential of nanotechnology while minimizing harm to humans.
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Chow, James C. L., and Sama Jubran. "Depth Dose Enhancement in Orthovoltage Nanoparticle-Enhanced Radiotherapy: A Monte Carlo Phantom Study." Micromachines 14, no. 6 (June 10, 2023): 1230. http://dx.doi.org/10.3390/mi14061230.
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Background: This study was to examine the depth dose enhancement in orthovoltage nanoparticle-enhanced radiotherapy for skin treatment by investigating the impact of various photon beam energies, nanoparticle materials, and nanoparticle concentrations. Methods: A water phantom was utilized, and different nanoparticle materials (gold, platinum, iodine, silver, iron oxide) were added to determine the depth doses through Monte Carlo simulation. The clinical 105 kVp and 220 kVp photon beams were used to compute the depth doses of the phantom at different nanoparticle concentrations (ranging from 3 mg/mL to 40 mg/mL). The dose enhancement ratio (DER), which represents the ratio of the dose with nanoparticles to the dose without nanoparticles at the same depth in the phantom, was calculated to determine the dose enhancement. Results: The study found that gold nanoparticles outperformed the other nanoparticle materials, with a maximum DER value of 3.77 at a concentration of 40 mg/mL. Iron oxide nanoparticles exhibited the lowest DER value, equal to 1, when compared to other nanoparticles. Additionally, the DER value increased with higher nanoparticle concentrations and lower photon beam energy. Conclusions: It is concluded in this study that gold nanoparticles are the most effective in enhancing the depth dose in orthovoltage nanoparticle-enhanced skin therapy. Furthermore, the results suggest that increasing nanoparticle concentration and decreasing photon beam energy lead to increased dose enhancement.
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Sutthavas, Pichaporn, Matthias Schumacher, Kai Zheng, Pamela Habibović, Aldo Roberto Boccaccini, and Sabine van Rijt. "Zn-Loaded and Calcium Phosphate-Coated Degradable Silica Nanoparticles Can Effectively Promote Osteogenesis in Human Mesenchymal Stem Cells." Nanomaterials 12, no. 17 (August 24, 2022): 2918. http://dx.doi.org/10.3390/nano12172918.
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Nanoparticles such as mesoporous bioactive glasses (MBGs) and mesoporous silica nanoparticles (MSN) are promising for use in bone regeneration applications due to their inherent bioactivity. Doping silica nanoparticles with bioinorganic ions could further enhance their biological performance. For example, zinc (Zn) is often used as an additive because it plays an important role in bone formation and development. Local delivery and dose control are important aspects of its therapeutic application. In this work, we investigated how Zn incorporation in MSN and MBG nanoparticles impacts their ability to promote human mesenchymal stem cell (hMSC) osteogenesis and mineralization in vitro. Zn ions were incorporated in three different ways; within the matrix, on the surface or in the mesopores. The nanoparticles were further coated with a calcium phosphate (CaP) layer to allow pH-responsive delivery of the ions. We demonstrate that the Zn incorporation amount and ion release profile affect the nanoparticle’s ability to stimulate osteogenesis in hMSCs. Specifically, we show that the nanoparticles that contain rapid Zn release profiles and a degradable silica matrix were most effective in inducing hMSC differentiation. Moreover, cells cultured in the presence of nanoparticle-containing media resulted in the highest induction of alkaline phosphate (ALP) activity, followed by culturing hMSC on nanoparticles immobilized on the surface as films. Exposure to nanoparticle-conditioned media did not increase ALP activity in hMSCs. In summary, Zn incorporation mode and nanoparticle application play an important role in determining the bioactivity of ion-doped silica nanoparticles.
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Kim, Sungi, Namjun Kim, Jinyoung Seo, Jeong-Eun Park, Eun Ho Song, So Young Choi, Ji Eun Kim, Seungsang Cha, Ha H. Park, and Jwa-Min Nam. "Nanoparticle-based computing architecture for nanoparticle neural networks." Science Advances 6, no. 35 (August 2020): eabb3348. http://dx.doi.org/10.1126/sciadv.abb3348.
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The lack of a scalable nanoparticle-based computing architecture severely limits the potential and use of nanoparticles for manipulating and processing information with molecular computing schemes. Inspired by the von Neumann architecture (VNA), in which multiple programs can be operated without restructuring the computer, we realized the nanoparticle-based VNA (NVNA) on a lipid chip for multiple executions of arbitrary molecular logic operations in the single chip without refabrication. In this system, nanoparticles on a lipid chip function as the hardware that features memory, processors, and output units, and DNA strands are used as the software to provide molecular instructions for the facile programming of logic circuits. NVNA enables a group of nanoparticles to form a feed-forward neural network, a perceptron, which implements functionally complete Boolean logic operations, and provides a programmable, resettable, scalable computing architecture and circuit board to form nanoparticle neural networks and make logical decisions.
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Olinger, Alexander D., Eric J. Spangler, P. B. Sunil Kumar, and Mohamed Laradji. "Membrane-mediated aggregation of anisotropically curved nanoparticles." Faraday Discussions 186 (2016): 265–75. http://dx.doi.org/10.1039/c5fd00144g.
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Using systematic numerical simulations, we study the self-assembly of elongated curved nanoparticles on lipid vesicles. Our simulations are based on molecular dynamics of a coarse-grained implicit-solvent model of self-assembled lipid membranes with a Langevin thermostat. Here we consider only the case wherein the nanoparticle–nanoparticle interaction is repulsive, only the concave surface of the nanoparticle interacts attractively with the lipid head groups and only the outer surface of the vesicle is exposed to the nanoparticles. Upon their adhesion on the vesicle, the curved nanoparticles generate local curvature on the membrane. The resulting nanoparticle-generated membrane curvature leads in turn to nanoparticle self-assembly into two main types of aggregates corresponding to chain aggregates at low adhesion strengths and aster aggregates at high adhesion strength. The chain-like aggregates are due to the fact that at low values of adhesion strength, the nanoparticles prefer to lie parallel to each other. As the adhesion strength is increased, a splay angle between the nanoparticles is induced with a magnitude that increases with increasing adhesion strength. The origin of the splay angles between the nanoparticles is shown to be saddle-like membrane deformations induced by a tilt of the lipids around the nanoparticles. This phenomenon of membrane mediated self-assembly of anisotropically curved nanoparticles is explored for systems with varying nanoparticle number densities, adhesion strength, and nanoparticle intrinsic curvature.
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Michelakaki, Irini, Nikos Boukos, Dimitrios A. Dragatogiannis, Spyros Stathopoulos, Costas A. Charitidis, and Dimitris Tsoukalas. "Synthesis of hafnium nanoparticles and hafnium nanoparticle films by gas condensation and energetic deposition." Beilstein Journal of Nanotechnology 9 (June 27, 2018): 1868–80. http://dx.doi.org/10.3762/bjnano.9.179.
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In this work we study the fabrication and characterization of hafnium nanoparticles and hafnium nanoparticle thin films. Hafnium nanoparticles were grown in vacuum by magnetron-sputtering inert-gas condensation. The as deposited nanoparticles have a hexagonal close-packed crystal structure, they possess truncated hexagonal biprism shape and are prone to surface oxidation when exposed to ambient air forming core–shell Hf/HfO2 structures. Hafnium nanoparticle thin films were formed through energetic nanoparticle deposition. This technique allows for the control of the energy of charged nanoparticles during vacuum deposition. The structural and nanomechanical properties of the nanoparticle thin films were investigated as a function of the kinetic energy of the nanoparticles. The results reveal that by proper adjustment of the nanoparticle energy, hexagonal close-packed porous nanoparticle thin films with good mechanical properties can be formed, without any additional treatment. It is shown that these films can be patterned on the substrate in sub-micrometer dimensions using conventional lithography while their porosity can be well controlled. The fabrication and experimental characterization of hafnium nanoparticles is reported for the first time in the literature.
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Osaci, Mihaela, and Matteo Cacciola. "Influence of the magnetic nanoparticle coating on the magnetic relaxation time." Beilstein Journal of Nanotechnology 11 (August 12, 2020): 1207–16. http://dx.doi.org/10.3762/bjnano.11.105.
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Colloidal systems consisting of monodomain superparamagnetic nanoparticles have been used in biomedical applications, such as the hyperthermia treatment for cancer. In this type of colloid, called a nanofluid, the nanoparticles tend to agglomeration. It has been shown experimentally that the nanoparticle coating plays an important role in the nanoparticle dispersion stability and biocompatibility. However, theoretical studies in this field are lacking. In addition, the ways in which the nanoparticle coating influences the magnetic properties of the nanoparticles are not yet understood. In order to fill in this gap, this study presents a numerical simulation model that elucidates how the nanoparticle coating affects the nanoparticle agglomeration tendency as well as the effective magnetic relaxation time of the system. To simulate the self-organization of the colloidal nanoparticles, a stochastic Langevin dynamics method was applied based on the effective Verlet-type algorithm. The Néel magnetic relaxation time was obtained via the Coffey method in an oblique magnetic field, adapted to the local magnetic field on a nanoparticle.
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Metin, Cigdem, Roger T. Bonnecaze, and Quoc P. Nguyen. "The Viscosity of Silica Nanoparticle Dispersions in Permeable Media." SPE Reservoir Evaluation & Engineering 16, no. 03 (July 24, 2013): 327–32. http://dx.doi.org/10.2118/157056-pa.
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Summary The potential application of nanoparticle dispersions as formation-stimulation agents, contrast agents, or simply as tracers in the upstream oil and gas industry requires knowledge of the flow properties of these nanoparticles. The modeling of nanoparticle transport in hydrocarbon reservoirs requires a comprehensive understanding of the rheological behavior of these nanofluids. Silica nanoparticles have been commonly used because of their low-cost fabrication and cost-effective surface modification. The aqueous silica-nanoparticle dispersions show Newtonian behavior under steady shear measurements controlled by a rheometer, as discussed by Metin et al. (2011b). The viscosity of nanoparticle dispersions depends strongly on the particle concentration, and that this correlation can be depicted by a unified rheological model (Metin et al. 2011b). In addition, during flow in permeable media, the variation of shear associated with complex pore morphology and the interactions between the nanoparticles and tortuous flow channels can affect the viscosity of nanoparticle dispersion. The latter is particularly important if the concentration of nanoparticles in dispersion may change because of nanoparticle adsorption on mineral/fluid and oil/water interfaces or by mechanical trapping of nanoparticles. In this paper, the flow of silica-nanoparticle dispersions through different permeable media is investigated. The rheological behaviors of the dispersions are compared with those determined by use of a rheometer. We established a correlation between the nanoparticle concentration and dispersion viscosity in porous media for various nanoparticle sizes. The effects of pore structure and shear rate are also studied. We have confirmed that the concept of effective maximum packing fraction can be applied to describe the viscosity of aqueous nanoparticle dispersions in both bulk flow and flow in porous media with high permeability and regular pore structures, but not at low permeability because of mechanical trapping. Our work provides new insight to engineering nanoparticle rheology for subsurface applications.
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Patrice, Fato Tano, Kaipei Qiu, Yi-Lun Ying, and Yi-Tao Long. "Single Nanoparticle Electrochemistry." Annual Review of Analytical Chemistry 12, no. 1 (June 12, 2019): 347–70. http://dx.doi.org/10.1146/annurev-anchem-061318-114902.
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Experimental techniques to monitor and visualize the behaviors of single nanoparticles have not only revealed the significant spatial and temporal heterogeneity of those individuals, which are hidden in ensemble methods, but more importantly, they have also enabled researchers to elucidate the origin of such heterogeneity. In pursuing the intrinsic structure-function relations of single nanoparticles, the recently developed stochastic collision approach demonstrated some early promise. However, it was later realized that the appropriate sizing of a single nanoparticle by an electrochemical method could be far more challenging than initially expected owing to the dynamic motion of nanoparticles in electrolytes and complex charge-transfer characteristics at electrode surfaces. This clearly indicates a strong necessity to integrate single nanoparticle electrochemistry with high-resolution optical microscopy. Hence, this review aims to give a timely update of the latest progress for both electrochemically sensing and seeing single nanoparticles. A major focus is on collision-based measurements, where nanoparticles or single entities in solution impact on a collector electrode and the electrochemical response is recorded. These measurements are further enhanced with optical measurements in parallel. For completeness, advances in other related methods for single nanoparticle electrochemistry are also included.
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Zhang, Tiantian, Michael J. Murphy, Haiyang Yu, Hitesh G. Bagaria, Ki Youl Yoon, Bethany M. Neilson, Christopher W. Bielawski, Keith P. Johnston, Chun Huh, and Steven L. Bryant. "Investigation of Nanoparticle Adsorption During Transport in Porous Media." SPE Journal 20, no. 04 (August 20, 2015): 667–77. http://dx.doi.org/10.2118/166346-pa.
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Summary Nanoparticles (diameter of approximately 5 to 50 nm) easily pass through typical pore throats in reservoirs, but physicochemical attraction between nanoparticles and pore walls may still lead to significant retention. We conducted an extensive series of nanoparticle-transport experiments in core plugs and in columns packed with crushed sedimentary rock, systematically varying flow rate, type of nanoparticle, injection-dispersion concentration, and porous-medium properties. Effluent-nanoparticle-concentration histories were measured with fine resolution in time, enabling the evaluation of nanoparticle adsorption in the columns during slug injection and post-flushes. We also applied this analysis to nanoparticle-transport experiments reported in the literature. Our analysis suggests that nanoparticles undergo both reversible and irreversible adsorption. Effluent-nanoparticle concentration reaches the injection concentration during slug injection, indicating the existence of an adsorption capacity. Experiments with a variety of nanoparticles and porous media yield a wide range of adsorption capacities (from 10–5 to 101 mg/g for nanoparticles and rock, respectively) and also a wide range of proportions of reversible and irreversible adsorption. Reversible- and irreversible-adsorption sites are distinct and interact with nanoparticles independently. The adsorption capacities are typically much smaller than monolayer coverage. Their values depend not only on the type of nanoparticle and porous media, but also on the operating conditions, such as injection concentration and flow rate.
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Rahmadani, Dewi, Sumiati Side, and Suriati Eka Putri. "Pengaruh Penambahan PVA terhadap Ukuran Nanopartikel Perak Hasil Sintesis Menggunakan Bioreduktor Ekstrak Daun Sirsak (Annona muricata L.)." Sainsmat : Jurnal Ilmiah Ilmu Pengetahuan Alam 9, no. 1 (July 3, 2020): 1. http://dx.doi.org/10.35580/sainsmat91141862020.
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Penelitian ini bertujuan untuk menentukan pengaruh penambahan Polivinil Alkohol (PVA) terhadap ukuran nanopartikel perak hasil sintesis menggunakan bioreduktor ekstrak daun sirsak (Annona muricata L.). Nanopartikel perak dibuat melalui metode bioreduksi, larutan bioreduktor dicampur dengan prekursor AgNO3, tanpa penambahan PVA dan dengan penambahan PVA dengan variasi konsentrasi yang berbeda yaitu 1%; 1,5%; 2%; dan 2,5%. Berdasarkan hasil analisis gugus fungsi ekstrak daun sirsak menggunakan spektrofotometer FT-IR (Fourier Transform Infrared), menunjukkan serapan pada bilangan gelombang 3443 cm-1 yang menunjukkan adanya gugus –OH. Proses pembentukan nanopartikel perak dilihat dengan mengamati serapan UV-Vis. Hasil pengukuran menunjukkan bahwa nilai absorbansi meningkat dengan meningkatnya waktu kontak. Proses pembentukan nanopartikel diamati menggunakan Spektrofotometer UV-Vis melalui serapan UV-Vis. Hasil pengukuran serapan maksimun dari sampel hasil sintesis masing-masing konsentrasi menunjukkan λmax 503.0; 463.1; 436.0; 476.1; 503.1 nm selama dua hari dengan variasi konsentrasi PVA berturut-turut tanpa PVA 1%; 1,5%; 2%; dan 2,5%. Ukuran nanopartikel perak ditentukan menggunakan XRD (X-Ray Diffraction), distribusi rata-rata ukuran nanopartikel perak dengan tanpa penambahan PVA yaitu 30,80-50,25 nm dan kisaran ukuran terkecil nanopartikel perak yaitu 9,90-10,20 nm dengan penambahan PVA 1,5%. Berdasarkan penelitian yang telah dilakukan, maka dapat disimpulkan bahwa penambahan PVA mempengaruhi ukuran nanopartikel perak. Hal ini terjadi karena stabilisator berperan untuk mengontrol ukuran nanopartikel perak.Kata Kunci: Annona muricata Linn, PVA, reduksi, nanopartikel perak This study aims to determine the effect of adding Polyvinyl Alcohol (PVA) to the size of silver nanoparticle synthesized using bioreductor soursop leaf extract (Annona muricata L.). Silver nanoparticle made through method bioreduction, bioreductor solution was mixed with AgNO3 precursor, without addition of PVA and with the addition of PVA. That the variant of concentrations is 1%; 1.5%; 2%; and 2.5%. Based on the analysis of functional groups of soursop leaf extract using a spectrophotometer FT-IR (Fourier Transform Infrared), showed absorption at wave number 3443 cm-1 which indicate a -OH group.The process of formation of silver nanoparticles seen by UV-Vis absorption. The measurement results shows that the absorbance value increased with increasing contact time. The maximum absorbance measurement result of the samples synthesized each concentration showed λmax 503.0; 463.1; 436.0; 476.1; 503.1 nm for two days with various concentrations without PVA, 1%, 1.5%, 2%, and 2.5%. The size of silver nanoparticle were determined using XRD (X-Ray Diffraction), the average size distribution of silver nanoparticle without the addition of PVA is 30.80-50.25 nm and the smallest size range is 9.90-10.20 nm silver nanoparticle with addition PVA 1.5%. Based on research that has been done, it can concluded that addition of PVA have the effect to the size of silver nanoparticle. The stabilizer acts to control the size of silver nanoparticle.Keywords: Annona muricata Linn, PVA, reduction, silver nanoparticle.
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Husnul Khotimah, Fathina Zahrani Rahmaniar, Fatimah Az Zahra, Rabjhany Anaqah, Shahdevi Nandar Kurniawan, Masruroh Rahayu, and Hikmawan Wahyu Sulistomo. "Unveiling the effects of nanoparticles-based antiepileptic drugs: Systematic review of in vivo studies." GSC Biological and Pharmaceutical Sciences 26, no. 3 (March 30, 2024): 140–58. http://dx.doi.org/10.30574/gscbps.2024.26.3.0099.
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Background: Resistance and side effects of antiepileptic drugs (AEDs) pose a challenge in epilepsy therapy due to the limited drug bioavailability in penetrating the Blood-Brain Barrier (BBB). Nanoparticles can be one solution by encapsulating AEDs to enhance drug distribution to target cells. This study systematically assesses 1) the characteristics of nanoparticles, and 2) the potential of nanoparticle AEDs in managing seizures in experimental animal models. Methods: This systematic literature review is limited to studies published between 2013 and July 2023 in the PubMed, ScienceDirect, ProQuest, MEDLINE, and Scopus databases. Inclusion criteria encompass studies involving animal models of epilepsy, that exploring nanoparticle-based of AEDs. These studies compare the characteristics of nanoparticles and their antiepileptic efficacy with non-nanoparticle groups. Review articles, publications in non-English languages, and ongoing studies without published results are excluded. Result and Discussion: Fourteen studies met the inclusion criteria for this research. All studies utilized nanoparticles (n = 14). Lipid nanoparticles have a more compact size than any other nanoparticle, while the combination preparation method has an optimal nanoparticle formation in both lipid and polymeric nanoparticles. In animal model results indicated that nanoparticle-based drugs were beneficial in reducing seizure scores, improving seizure onset latency, and providing neuroprotective effects. Conclusion: The characteristics of nanoparticle drug delivery varied, influenced by formulation factors and preparation methods. Nanoparticle-based AEDs exhibit higher efficacy compared to conventional AEDs. All studies included present an opportunity for the development of epilepsy therapies, although future studies are needed to confirm these findings.
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Abdillah, Hamid, Muhammad Baharits, Rijal Abidin, and Firdaus Rizki Biantoro. "Synthesis of Antimicrobial Silver Nanoparticle Varnish using Moringa Leaf Bioreductor (Moringa Olifiera)." Jurnal Kimia dan Rekayasa 2, no. 2 (January 21, 2022): 84–93. http://dx.doi.org/10.31001/jkireka.v2i2.38.
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Silver nanoparticles have stable properties and potential applications especially as anti-microbial agents. The growth of fungi and bacteria on the wood surface can be inhibited by varnishing with silver nanoparticles. The nano-silver particles were prepared by synthesizing silver nitrate at concentration of 1, 3, and 5 mM with Moringa oleifera as a bioreductant. PVA (Polyvinyl Alcohol) as a stabilizer was varied at the levels of 0.5%, 1%, and 2%. In the UV-Vis test, the wave peaks are in the range 395-515 nm, this is in accordance with the characteristics of silver nanoparticles. The addition of 1% PVA to silver nanoparticles provided the best stability among the four concentrations provided by evidence of low maximum wavelength shift after storing. Particle size examination using the Particle Size Analyzer (PSA) showed silver nanoparticles had a size of 75.6 nm. Then the silver nanoparticle solution was applied to the resin varnish. The solution of silver nanoparticles has an effect on the antimicrobial properties of resin varnish, as evidenced by the absence of mold growth in the media with silver nanoparticles added. Abstrak Nanopartikel perak memiliki sifat yang stabil dan aplikasi yang potensial khususnya sebagai agen anti-mikroba. Pertumbuhan jamur dan bakteri pada permukaan kayu dapat dihambat dengan pernis yang diberi bahan nanopartikel perak. Partikel nano-perak dibuat melalui sintesis perak nitrat konsentrasi 1, 3, dan 5 mM dengan bioreduktor daun kelor (Moringa oleifera). PVA (Polivinil Alkohol) sebagai stabilsator divariasikan pada kadar 0,5, 1, dan 2%. Pada pengujian UV-Vis, puncak gelombang berada pada rentang 395-515 nm yang sesuai dengan karakteristik nanopartikel perak. Penambahan PVA 1% pada nanopartikel perak memberikan kestabilan paling baik diantara keempat konsentrasi karena pergeseran panjang gelombang maksimal yang rendah. Pemeriksaan ukuran partikel menggunakan Partikel Size Analyzer ( PSA ) menunjukkan nanopartikel perak memiliki ukuran 75,6 nm. Selanjutnya larutan nanopartikel perak tersebut diaplikasikan pada pernis damar. Larutan nanopartikel perak berpengaruh terhadap sifat anti mikroba pada pernis damar, dibuktikan dengan tidak tumbuhnya jamur pada media yang ditambahkan nanopartikel perak.
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Dhar, Sunandan, Vishesh Sood, Garima Lohiya, Harini Deivendran, and Dhirendra S. Katti. "Role of Physicochemical Properties of Protein in Modulating the Nanoparticle-Bio Interface." Journal of Biomedical Nanotechnology 16, no. 8 (August 1, 2020): 1276–95. http://dx.doi.org/10.1166/jbn.2020.2958.
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Nanoparticles, on exposure to the biological milieu, tend to interact with macromolecules to form a biomolecular corona. The biomolecular corona confers a unique biological identity to nanoparticles, and its protein composition plays a deterministic role in the biological fate of nanoparticles. The physiological behavior of proteins stems from their physicochemical properties, including surface charge, hydrophobicity, and structural stability. However, there is insufficient understanding about the role of physicochemical properties of proteins in biomolecular corona formation. We hypothesized that the physicochemical properties of proteins would influence their interaction with nanoparticles and have a deterministic effect on nanoparticle-cell interactions. To test our hypothesis, we used model proteins from different structural classes to understand the effect of secondary structure elements of proteins on the nanoparticle-protein interface. Further, we modified the surface of proteins to study the role of protein surface characteristics in governing the nanoparticle-protein interface. For this study, we used mesoporous silica nanoparticles as a model nanoparticle system. We observed that the surface charge of proteins governs the nature of the primary interaction and the extent of subsequent secondary interactions causing structural rearrangements of the protein. We also observed that the secondary structural contents of proteins significantly affected both the extent of secondary interactions at the nanoparticle-protein interface and the dispersion state of the nanoparticle-protein complex. Further, we studied the interactions of different protein-coated nanoparticles with different cells (fibroblast, carcinoma, and macrophage). We observed that different cells internalized the nanoparticle-protein complex as a function of secondary structural components of the protein. The type of model protein had a significant effect on their internalization by macrophages. Overall, we observed that the physicochemical characteristics of proteins had a significant role in modulating the nanoparticle-bio-interface at the level of both biomolecular corona formation and nanoparticle internalization by cells.
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Knauer, Andrea, and J. Michael Koehler. "Screening of nanoparticle properties in microfluidic syntheses." Nanotechnology Reviews 3, no. 1 (February 1, 2014): 5–26. http://dx.doi.org/10.1515/ntrev-2013-0018.
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AbstractThe possible diversity of nanoparticles is extremely high. This variability corresponds to a huge potential of possible functions in future materials and nanotechnical devices. Apart from rational designs, there is an urgent need for screening strategies for specific nanoparticle properties. Miniaturized screening techniques are challenged for efficient screening procedures. The review gives an overview on the possibilities of tuning and screening of nanoparticle properties and focuses on the application of microfluidic techniques for nanoparticle synthesis. Furthermore, the variation of parameters during the generation of nanoparticles and its connection with the resulting nanoparticle properties are highlighted as well. Among other microfluidic techniques, microsegmented flow is particularly promising for the synthesis of different types of homogeneous nanoparticles and offers interesting approaches for the screening of process parameters and nanoparticle properties. The tuning of reactant concentrations in the micro-flow-through synthesis of nonspherical silver particles and gold/silver core/shell particles and their effects on the shape, size, and optical parameters of the formed nanoparticles are given as examples for the application of microsegmented flow in the screening of nanoparticle properties.
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Kingston, Benjamin R., Abdullah Muhammad Syed, Jessica Ngai, Shrey Sindhwani, and Warren C. W. Chan. "Assessing micrometastases as a target for nanoparticles using 3D microscopy and machine learning." Proceedings of the National Academy of Sciences 116, no. 30 (July 8, 2019): 14937–46. http://dx.doi.org/10.1073/pnas.1907646116.
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Metastasis of solid tumors is a key determinant of cancer patient survival. Targeting micrometastases using nanoparticles could offer a way to stop metastatic tumor growth before it causes excessive patient morbidity. However, nanoparticle delivery to micrometastases is difficult to investigate because micrometastases are small in size and lie deep within tissues. Here, we developed an imaging and image analysis workflow to analyze nanoparticle–cell interactions in metastatic tumors. This technique combines tissue clearing and 3D microscopy with machine learning-based image analysis to assess the physiology of micrometastases with single-cell resolution and quantify the delivery of nanoparticles within them. We show that nanoparticles access a higher proportion of cells in micrometastases (50% nanoparticle-positive cells) compared with primary tumors (17% nanoparticle-positive cells) because they reside close to blood vessels and require a small diffusion distance to reach all tumor cells. Furthermore, the high-throughput nature of our image analysis workflow allowed us to profile the physiology and nanoparticle delivery of 1,301 micrometastases. This enabled us to use machine learning-based modeling to predict nanoparticle delivery to individual micrometastases based on their physiology. Our imaging method allows researchers to measure nanoparticle delivery to micrometastases and highlights an opportunity to target micrometastases with nanoparticles. The development of models to predict nanoparticle delivery based on micrometastasis physiology could enable personalized treatments based on the specific physiology of a patient’s micrometastases.
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Chavanpatil, Mahesh D., Ayman Khdair, and Jayanth Panyam. "Nanoparticles for Cellular Drug Delivery: Mechanisms and Factors Influencing Delivery." Journal of Nanoscience and Nanotechnology 6, no. 9 (September 1, 2006): 2651–63. http://dx.doi.org/10.1166/jnn.2006.443.
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Polymeric nanoparticles have demonstrated enormous potential as cellular drug delivery vehicles. Nanoparticles improve drug's stability as well as its availability and retention at the target intracellular site of action. Therapeutic efficacy of nanoparticles can be further enhanced by conjugating specific ligands to nanoparticle surface. Ligand conjugation can also be used to favorably modify the intracellular disposition of nanoparticles. A number of ligands are available for this purpose; use of a specific ligand depends on the target cell, the material used for nanoparticle formulation, and the chemistry available for ligand-nanoparticle conjugation. Cellular drug delivery using nanoparticles is also affected by clearance through the reticuloendothelial system. In this paper, we review the recent progress on our understanding of physicochemical factors that affect the cellular uptake of nanoparticles and the different cellular processes that could be exploited to enhance nanoparticle uptake into cells.
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Johnstone, Sharon, Steven Ansell, Sherwin Xie, Lawrence Mayer, and Paul Tardi. "The Use of Radioactive Marker as a Tool to Evaluate the Drug Release in Plasma and Particle Biodistribution of Block Copolymer Nanoparticles." Journal of Drug Delivery 2011 (July 7, 2011): 1–9. http://dx.doi.org/10.1155/2011/349206.
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Diblock copolymer nanoparticles encapsulating a paclitaxel prodrug, Propac 7, have been used to demonstrate the usefulness of a nonmetabolizable radioactive marker, cholesteryl hexadecyl ether (CHE), to evaluate nanoparticle formulation variables. Since CHE did not exchange out of the nanoparticles, the rate of clearance of the CHE could be used as an indicator of nanoparticle stability in vivo. We simultaneously monitored prodrug circulation and carrier circulation in the plasma and the retention of CHE relative to the retention of prodrug in the plasma was used to distinguish prodrug release from nanoparticle plasma clearance. Nanoparticles labelled with CHE were also used to evaluate accumulation of nanoparticles in the tumour. This marker has provided relevant data which we have applied to optimise our nanoparticle formulations.
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Devi, Geetha, Joefel Jessica C. Dumaran, and Dinesh Keloth Kaithari. "Nanoparticle Mediated Treatment of Dairy Wastewater." E3S Web of Conferences 463 (2023): 03015. http://dx.doi.org/10.1051/e3sconf/202346303015.
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Nanotechnology is one of the emerging areas of scientific interest with numerous applications. In this research, surface modified silicon dioxide nanoparticules have been developed from low molecular weight chitosan by dip-coating technique for the batch treatment of dairy wastewater. The processing parameters of wastewater pH, mixing duration, agitation speed and quantity of nanoparticles are varied, and the treatment efficiency was established by measuring the total dissolved solids (TDS), turbidity, chemical oxygen demand (COD), total suspended solids (TSS), and dissolved oxygen (DO). Dynamic light scattering (DLS), scanning electron microscopy (SEM), energy dispersive X-Ray analysis (EDX), and fourier transform infrared spectrocopy (FTIR) are employed as characterization techniques. The DLS analysis showed the average diameter of the nanoparticles as 320 nm and the EDX analysis confirmed the elemental composition of the silicon dioxide nanoparticles. The functional groups are identified by FTIR. The optimum values for the best treatment conditions are established as pH 3.0, 60 minutes contact time, 100 rpm agitation speed and a nanoparticle dosage of 0.6 g. The batch expérimental study démontrâtes that the surface modified silicon dioxide nanoparticles could efficiently remove the polluants from the dairy wastewater in an environmentally friendly and cost effective method.
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Huynh, Ngoc Han, and James C. L. Chow. "DNA Dosimetry with Gold Nanoparticle Irradiated by Proton Beams: A Monte Carlo Study on Dose Enhancement." Applied Sciences 11, no. 22 (November 17, 2021): 10856. http://dx.doi.org/10.3390/app112210856.
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Heavy atom nanoparticles, such as gold nanoparticles, are proven effective radiosensitizers in radiotherapy to enhance the dose delivery for cancer treatment. This study investigated the effectiveness of cancer cell killing, involving gold nanoparticle in proton radiation, by changing the nanoparticle size, proton beam energy, and distance between the nanoparticle and DNA. Monte Carlo (MC) simulation (Geant4-DNA code) was used to determine the dose enhancement in terms of dose enhancement ratio (DER), when a gold nanoparticle is present with the DNA. With varying nanoparticle size (radius = 15–50 nm), distance between the gold nanoparticle and DNA (30–130 nm), as well as proton beam energy (0.5–25 MeV) based on the simulation model, our results showed that the DER value increases with a decrease of distance between the gold nanoparticle and DNA and a decrease of proton beam energy. The maximum DER (1.83) is achieved with a 25 nm-radius gold nanoparticle, irradiated by a 0.5 MeV proton beam and 30 nm away from the DNA.
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Johnston, Stuart T., Matthew Faria, and Edmund J. Crampin. "An analytical approach for quantifying the influence of nanoparticle polydispersity on cellular delivered dose." Journal of The Royal Society Interface 15, no. 144 (July 2018): 20180364. http://dx.doi.org/10.1098/rsif.2018.0364.
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Nanoparticles provide a promising approach for the targeted delivery of therapeutic, diagnostic and imaging agents in the body. However, it is not yet fully understood how the physico-chemical properties of the nanoparticles influence cellular association and uptake. Cellular association experiments are routinely performed in an effort to determine how nanoparticle properties impact the rate of nanoparticle–cell association. To compare experiments in a meaningful manner, the association data must be normalized by the amount of nanoparticles that arrive at the cells, a measure referred to as the delivered dose. The delivered dose is calculated from a model of nanoparticle transport through fluid. A standard assumption is that all nanoparticles within the population are monodisperse, namely the nanoparticles have the same physico-chemical properties. We present a semi-analytic solution to a modified model of nanoparticle transport that allows for the nanoparticle population to be polydisperse. This solution allows us to efficiently analyse the influence of polydispersity on the delivered dose. Combining characterization data obtained from a range of commonly used nanoparticles and our model, we find that the delivered dose changes by more than a factor of 2 if realistic amounts of polydispersity are considered.
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Lestari, Tresna, Tita Nofianti, Lilis Tuslinah, Ruswanto Ruswanto, and Firda Adityas. "Karakterisasi Nanopartikel Ekstrak Bunga Kecombrang dengan Penambahan Poloksamer." Talenta Conference Series: Tropical Medicine (TM) 1, no. 3 (December 20, 2018): 121–24. http://dx.doi.org/10.32734/tm.v1i3.275.
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Bunga kecombrang diketahui memiliki aktivitas sebagai antioksidan. Teknologi formulasi nanopartikel diharapkan dapat meningkatkan aktivitas biologis dari ekstrak.Penelitian ini dilakukan untuk memperoleh nanopartikel dari ekstrak bunga kecombrang dengan karakteristik yang baik.Pembuatan nanopartikel dilakukan dengan penambahan poloksamer dengan variasi konsentrasi 1, 3 dan 5%. Formulasi selanjutnya dianalisis meliputi ukuran partikel rata-rata, indeks polidispersitas, potensial zeta, efisiensi penjeratan dan morfologi partikel menggunakan SEM.Hasil karakterisasi diperoleh ukuran partikel rata-rata ketiga formula berada dalam rentang 134,7-193,1 nm, indeks polidispersitas <0,5 untuk semua formula, nilai potensial zeta antara -41,0 - (-24,3) mV dan efisiensi penjeratan terhadap senyawa flavonoid 89,93-97,99 %. Berdasarkan hasil SEM nanopartikel diketahui berbentuk bulat dengan permukaan yang halus.Berdasarkan hasil penelitian disimpulkan bahwa nanopartikel ekstrak bunga kecombrang dengan penambahan poloksamer 1, 3 dan 5% memiliki karakteristik yang baik dan memenuhi syarat sebagai sediaan nanopartikel.
Kecombrang flowers are known to have antioxidant activity. Nanoparticle formulation technology is expected to increase the biological activity of the extract. This study was conducted to obtain the nanoparticles from kecombrang flower extract with good characteristics. The preparation of nanoparticles was carried out by adding poloxamer with various concentrations of 1, 3 and 5%.Furthermore, the formula were analyzed, including the average particle size, polydispersity index, zeta potential, entrapment efficiency and particle morphology using SEM. The results of the characterization obtained an average particle size of the three formulas in the range of 134.7-193.1 nm, polydispersity index <0 , 5 for all formulas, zeta potential values in range of -41.0 - (-24.3) mV and entrapment efficiency of flavonoid compounds of 89.93-97.99%The results of SEM examination showed that nanoparticles was in round form with a smooth surface. Based on the results of the study, itcan be concluded that kecombrang flower extract nanoparticles with the addition of poloxamer 1, 3 and 5% had good characteristics and met the criteria of nanoparticle
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Bertholon, Isabelle, Gilles Ponchel, Denis Labarre, Patrick Couvreur, and Christine Vauthier. "Bioadhesive Properties of Poly(alkylcyanoacrylate) Nanoparticles Coated with Polysaccharide." Journal of Nanoscience and Nanotechnology 6, no. 9 (September 1, 2006): 3102–9. http://dx.doi.org/10.1166/jnn.2006.418.
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Development of bioadhesive nanoparticles is of great interest to improve drug absorption through the intestinal barrier. Various Polysaccharide-coated poly(alkylcyanoacrylate) nanoparticles were prepared. The bioadhesive properties of the nanoparticles coated with dextran or chitosan in end-on or side-on conformation were evaluated with an ex-vivo adsorption experiment on rat intestine. Results show that diffusion of nanoparticles in mucus layer was governed by the nanoparticle diameter and isotherms of adsorption were influenced by the nature of polysaccharide used. High amount of nanoparticles coated with chitosan can be entrapped in the mucus layer even at low nanoparticle concentration in suspension. When nanoparticle concentration increased, a pseudo-plateau was reached. In the case of dextran-coated nanoparticles, linear increase of adsorption was observed and no saturation phenomenon was highlighted over the range of nanoparticle concentration used in this study. These results suggested that interactions involved in bioadhesion mechanism depended on the nature of polysaccharide. Electrostatic interactions are enhanced between chitosan-coated nanoparticles and glycoproteins of mucus leading to a saturated adsorption phenomenon whereas dextran-coated nanoparticles interacted by non-electrostatic interactions with mucus resulting in a non-saturated phenomenon. Polysaccharides grafted at the nanoparticle surface in the brush conformation appeared more favorable to promote interactions of nanoparticles with glycoproteins of mucus in comparison with the more compact loop conformation of polysaccharide chains.
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Drozdov, Andrey S., Petr I. Nikitin, and Julian M. Rozenberg. "Systematic Review of Cancer Targeting by Nanoparticles Revealed a Global Association between Accumulation in Tumors and Spleen." International Journal of Molecular Sciences 22, no. 23 (December 1, 2021): 13011. http://dx.doi.org/10.3390/ijms222313011.
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Active targeting of nanoparticles toward tumors is one of the most rapidly developing topics in nanomedicine. Typically, this strategy involves the addition of cancer-targeting biomolecules to nanoparticles, and studies on this topic have mainly focused on the localization of such formulations in tumors. Here, the analysis of the factors determining efficient nanoparticle targeting and therapy, various parameters such as types of targeting molecules, nanoparticle type, size, zeta potential, dose, and the circulation time are given. In addition, the important aspects such as how active targeting of nanoparticles alters biodistribution and how non-specific organ uptake influences tumor accumulation of the targeted nanoformulations are discussed. The analysis reveals that an increase in tumor accumulation of targeted nanoparticles is accompanied by a decrease in their uptake by the spleen. There is no association between targeting-induced changes of nanoparticle concentrations in tumors and other organs. The correlation between uptake in tumors and depletion in the spleen is significant for mice with intact immune systems in contrast to nude mice. Noticeably, modulation of splenic and tumor accumulation depends on the targeting molecules and nanoparticle type. The median survival increases with the targeting-induced nanoparticle accumulation in tumors; moreover, combinatorial targeting of nanoparticle drugs demonstrates higher treatment efficiencies. Results of the comprehensive analysis show optimal strategies to enhance the efficiency of actively targeted nanoparticle-based medicines.
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Ulanova, Marina, Lucy Gloag, Andre Bongers, Chul-Kyu Kim, Hong Thien Kim Duong, Ha Na Kim, John Justin Gooding, et al. "Evaluation of Dimercaptosuccinic Acid-Coated Iron Nanoparticles Immunotargeted to Amyloid Beta as MRI Contrast Agents for the Diagnosis of Alzheimer’s Disease." Cells 12, no. 18 (September 14, 2023): 2279. http://dx.doi.org/10.3390/cells12182279.
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Nanoparticle-based magnetic contrast agents have opened the potential for magnetic resonance imaging (MRI) to be used for early non-invasive diagnosis of Alzheimer’s disease (AD). Accumulation of amyloid pathology in the brain has shown association with cognitive decline and tauopathy; hence, it is an effective biomarker for the early detection of AD. The aim of this study was to develop a biocompatible magnetic nanoparticle targeted to amyloid beta (Aβ) plaques to increase the sensitivity of T2-weighted MRI for imaging of amyloid pathology in AD. We presented novel iron core-iron oxide nanoparticles stabilized with a dimercaptosuccinic acid coating and functionalized with an anti-Aβ antibody. Nanoparticle biocompatibility and cellular internalization were evaluated in vitro in U-251 glioblastoma cells using cellular assays, proteomics, and transmission electron microscopy. Iron nanoparticles demonstrated no significant in vitro cytotoxicity, and electron microscopy results showed their movement through the endocytic cycle within the cell over a 24 h period. In addition, immunostaining and bio-layer interferometry confirmed the targeted nanoparticle’s binding affinity to amyloid species. The iron nanoparticles demonstrated favourable MRI contrast enhancement; however, the addition of the antibody resulted in a reduction in the relaxivity of the particles. The present work shows promising preliminary results in the development of a targeted non-invasive method of early AD diagnosis using contrast-enhanced MRI.
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Marangoni, Valeria S., Oara Neumann, Luke Henderson, Caterina C. Kaffes, Hui Zhang, Runmin Zhang, Sandra Bishnoi, et al. "Enhancing T1 magnetic resonance imaging contrast with internalized gadolinium(III) in a multilayer nanoparticle." Proceedings of the National Academy of Sciences 114, no. 27 (June 19, 2017): 6960–65. http://dx.doi.org/10.1073/pnas.1701944114.
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Multifunctional nanoparticles for biomedical applications have shown extraordinary potential as contrast agents in various bioimaging modalities, near-IR photothermal therapy, and for light-triggered therapeutic release processes. Over the past several years, numerous studies have been performed to synthesize and enhance MRI contrast with nanoparticles. However, understanding the MRI enhancement mechanism in a multishell nanoparticle geometry, and controlling its properties, remains a challenge. To systematically examine MRI enhancement in a nanoparticle geometry, we have synthesized MRI-active Au nanomatryoshkas. These are Au core–silica layer–Au shell nanoparticles, where Gd(III) ions are encapsulated within the silica layer between the inner core and outer Au layer of the nanoparticle (Gd-NM). This multifunctional nanoparticle retains its strong near-IR Fano-resonant optical absorption properties essential for photothermal or other near-IR light-triggered therapy, while simultaneously providing increased T1 contrast in MR imaging by concentrating Gd(III) within the nanoparticle. Measurements of Gd-NM revealed a strongly enhanced T1 relaxivity (r1 ∼ 24 mM−1⋅s−1) even at 4.7 T, substantially surpassing conventional Gd(III) chelating agents (r1 ∼ 3 mM−1⋅s−1 at 4.7 T) currently in clinical use. By varying the thickness of the outer gold layer of the nanoparticle, we show that the observed relaxivities are consistent with Solomon–Bloembergen–Morgan (SBM) theory, which takes into account the longer-range interactions between the encapsulated Gd(III) and the protons of the H2O molecules outside the nanoparticle. This nanoparticle complex and its MRI T1-enhancing properties open the door for future studies on quantitative tracking of therapeutic nanoparticles in vivo, an essential step for optimizing light-induced, nanoparticle-based therapies.
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Wang, Kun, Yuqing Zhang, Lincun Jiang, Zhiyuan Li, Xin Wang, Jinwei Zhai, and Siao Zhang. "Understanding the effect of ambient gas pressure on the nanoparticle formation in electrically exploding wires." Physics of Plasmas 30, no. 3 (March 2023): 033511. http://dx.doi.org/10.1063/5.0120712.
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In this paper, a computational model characterizing the preparation of metallic nanoparticles by electrically exploding wires from the onset of current flowing through the wire to the final moment of nanoparticle formation in a gaseous environment is constructed. The computational model consists of a 1D magnetohydrodynamic model, a simplified magnetohydrodynamic model with two-temperature approximation, and a set of general dynamic equations based on the nodal approach, corresponding to the phase transition stage, plasma evolution stage, and nanoparticle growth stage, respectively. The numerical investigation on the formation of nanoparticles is performed with “cold-start” conditions. The computational predictions for the dependence of nanoparticle size on proportion under argon gas pressure of 10 kPa demonstrate that the nanoparticles of 21 nm in diameter account for the maximum proportion of 4.3%. It coincides with the experimental measurements for nanoparticles of 19 nm in diameter with the maximum proportion of 3.5%. The computational model is employed to reveal the influence of ambient gas pressures on the process of nanoparticle formation. The variation trends for parameters of exploding products, cooling rate, and nanoparticle diameter with the largest proportion on ambient gas pressures are discussed. The size distribution of nanoparticles under different argon gas pressures matches relatively well with relevant experimental data. This computational model bridges the gap between the electrically exploding wires and the growth of nanoparticles, providing theoretical support for the regulation and control technology in nanoparticle synthesization by electrically exploding wires.
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Pedraza, A. J., J. D. Fowlkes, D. A. Blom, and H. M. Meyer. "Laser-induced nanoparticle ordering." Journal of Materials Research 17, no. 11 (November 2002): 2815–22. http://dx.doi.org/10.1557/jmr.2002.0409.
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Nanoparticles were produced on the surface of silicon upon pulsed-laser irradiation in the presence of an inert gas atmosphere at fluences close to the melting threshold. It was observed that nanoparticle formation required redeposition of ablated material. Redeposition took place in the form of a thin film intermixed with extremely small nanoparticles possibly formed in the gas phase. Through the use of nonpolarized laser light, it was shown that nanoparticles, fairly uniform in size, became grouped into curvilinear strings distributed with a short-range ordering. Microstructuring of part of the surface prior to the laser treatment had the remarkable effect of producing nanoparticles lying along straight and fairly long (approximately 1 mm) lines, whose spacing equaled the laser wavelength for normal beam incidence. In this work, it is shown that the use of polarized light eliminated the need of an aiding agent: nanoparticle alignment ensued under similar laser treatment conditions. The phenomenon of nanoparticle alignment bears a striking similarity with the phenomenon of laser-induced periodic surface structures (LIPSS), obeying the same dependence of line spacing upon light wavelength and beam angle of incidence as the grating spacing in LIPSS. The new results strongly support the proposition that the two phenomena, LIPSS and laser-induced nanoparticle alignment, evolve as a result of the same light interference mechanism.
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Nourafkan, E., Z. Hu, M. Garum, H. Esmaeili, and D. Wen. "Nanomaterials for subsurface application: study of particles retention in porous media." Applied Nanoscience 11, no. 6 (May 7, 2021): 1847–56. http://dx.doi.org/10.1007/s13204-021-01843-2.
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AbstractThe ability to transport nanoparticles through porous media has interesting engineering applications, notably in reservoir capacity exploration and soil remediation. A series of core-flooding experiments were conducted for quantitative analysis of functionalized TiO2 nanoparticles transport through various porous media including calcite, dolomite, silica, and limestone rocks. The adsorption of surfactants on the rock surface and nanoparticle retention in pore walls were evaluated by chemical oxygen demand (COD) and UV–Vis spectroscopy. By applying TiO2 nanoparticles, 49.3 and 68.0 wt.% of surfactant adsorption reduction were observed in pore walls of dolomite and silica rock, respectively. Not surprisingly, the value of nanoparticle deposition for dolomite and silica rocks was near zero, implying that surfactant adsorption is proportional to nanoparticle deposition. On the other hand, surfactant adsorption was increased for other types of rock in presence of nanoparticles. 5.5, 13.5, and 22.4 wt.% of nanoparticle deposition was estimated for calcite, black and red limestone, respectively. By making a connection between physicochemical rock properties and nanoparticle deposition rates, we concluded that the surface roughness of rock has a significant influence on mechanical trapping and deposition of nanoparticles in pore-throats.
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Gagliardi, Frank M., Rick D. Franich, and Moshi Geso. "Nanoparticle dose enhancement of synchrotron radiation in PRESAGE dosimeters." Journal of Synchrotron Radiation 27, no. 6 (October 23, 2020): 1590–600. http://dx.doi.org/10.1107/s1600577520012849.
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The physical absorbed dose enhancement by the inclusion of gold and bismuth nanoparticles fabricated into water-equivalent PRESAGE dosimeters was investigated. Nanoparticle-loaded water-equivalent PRESAGE dosimeters were irradiated with superficial, synchrotron and megavoltage X-ray beams. The change in optical density of the dosimeters was measured using UV–Vis spectrophotometry pre- and post-irradiation using a wavelength of 630 nm. Dose enhancement was measured for 5 nm and 50 nm monodispersed gold nanoparticles, 5–50 nm polydispersed bismuth nanoparticles, and 80 nm monodispersed bismuth nanoparticles at concentrations from 0.25 mM to 2 mM. The dose enhancement was highest for the 95.3 keV mean energy synchrotron beam (16–32%) followed by the 150 kVp superficial beam (12–21%) then the 6 MV beam (2–5%). The bismuth nanoparticle-loaded dosimeters produced a larger dose enhancement than the gold nanoparticle-loaded dosimeters in the synchrotron beam for the same concentration. For the superficial and megavoltage beams the dose enhancement was similar for both species of nanoparticles. The dose enhancement increased with nanoparticle concentration in the dosimeters; however, there was no observed nanoparticle size dependence on the dose enhancement.
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Ishak, Mohamad Nizam, K. A. Yaacob, and Ahmad Fauzi Mohd Noor. "The Effect of Ligands on CdSe Nanoparticle Films Deposited by EPD." Advanced Materials Research 1087 (February 2015): 304–8. http://dx.doi.org/10.4028/www.scientific.net/amr.1087.304.
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Nanoparticle from group II-IV semiconductor nanoparticles is widely studied for solar cells. The ability to modify the surface of nanoparticle is significant to successful use in various applications. In this research, mercaptoundecionic acid (MUA) and trioctyl phosphine oxide (TOPO) were used as ligand for cadmium selenide (CdSe) nanoparticles. The wavelength shift to a shorter value observed due to decreasing size of CdSe nanoparticle after ligand exchange from TOPO to MUA. The electrophoretic deposition methods (EPD) have being employed to deposite CdSe nanoparticles films on fluorine doped tin oxide (FTO). The deposition voltages used are between 100 - 400 V for 15 minutes. From SEM results show the formation layer of CdSe nanoparticles capped with MUA is strong and porous as compared to CdSe nanoparticle capped with TOPO. MUA capped CdSe shows better cell efficiency compared to TOPO capped CdSe which is 0.1735 %.
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Huang, Shan, and Jun-Jie Zhu. "Linkage Pathways of DNA–Nanoparticle Conjugates and Biological Applications." Chemosensors 11, no. 8 (August 10, 2023): 444. http://dx.doi.org/10.3390/chemosensors11080444.
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DNA–nanoparticle conjugates have extraordinary optical and catalytic properties that have attracted great interest in biosensing and biomedical applications. Combining these special qualities has made it possible to create extremely sensitive and selective biomolecule detection methods, as well as effective nanopharmaceutical carriers and therapy medications. In particular, inorganic nanoparticles, such as metal nanoparticles, metal–organic framework nanoparticles, or upconversion nanoparticles with relatively inert surfaces can easily bind to DNA through covalent bonds, ligand bonds, electrostatic adsorption, biotin–streptavidin interactions and click chemistry to form DNA–nanoparticle conjugates for a broad range of applications in biosensing and biomedicine due to their exceptional surface modifiability. In this review, we summarize the recent advances in the assembly mechanism of DNA–nanoparticle conjugates and their biological applications. The challenges of designing DNA–nanoparticle conjugates and their further applications are also discussed.
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Kim, Ji‐Hyun, Gil‐Suk Yang, Sanggeun Song, and Jaeyoung Sung. "Statistical Distribution of Laser‐induced Growth of Nanoparticles: Effects of Laser Intensity and Medium–Nanoparticles Interactions#." Bulletin of the Korean Chemical Society 36, no. 3 (February 26, 2015): 914–18. http://dx.doi.org/10.1002/bkcs.10171.
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We theoretically investigate the size distribution of nanoaggregates created by a laser‐induced monomer generation process, an example of which can be found in J. Phys. Chem. C 2008, 112, 10715. A simple analytic expression for the most probable size distribution of nanoparticles is obtained by considering statistical ensemble of nanoparticles with various sizes. When effects of the surface interaction and the defect degeneracy of the nanoparticle are negligible, the most probable size distribution of nanoparticles is given by the exponentially decaying function of the nanoparticle size. The presence of defect degeneracy drastically changes the size distribution to be like gamma distribution. The electronic surface tension of the nanoparticle and the interaction between the nanoparticle and environment make the size distribution deviate from gamma distribution, which also significantly change the mean and the variance of the size distribution of the nanoparticles.
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Cui, Jinhui, Haixin Cui, Yan Wang, Changjiao Sun, Kui Li, Hongyan Ren, and Wei Du. "Application of PEI-Modified Magnetic Nanoparticles as Gene Transfer Vector for the Genetic Modification of Animals." Advances in Materials Science and Engineering 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/764521.
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To evaluate the performance of the magnetic nanoparticles as gene transfer vector for breeding transgenic animals, we investigated a new approach to deliver green fluorescent protein (GFP) gene to porcine kidney 15 (PK-15) and porcine embryonic fibroblast (PEF) cells using PEI-modified magnetic nanoparticles as gene vector. The morphology of the nanoparticles and nanoparticle/DNA complexes was characterized using scanning electron microscopy. It was found that the surface of the particles becomes coarse and rough with increased average diameter, which implied the effective conjugating between nanoparticles with DNA. The zeta potential of nanoparticle/DNA complexes drops down from +29.4 mV to +23.1 mV comparing with pure nanoparticles. Agarose gel electrophoresis experiments show that DNA plasmids can be protected effectively against degradation of exonuclease and endonuclease. The efficiency of gene delivery was affected by the mass ratio of nanoparticle/DNA and the amount of nanoparticle/DNA complexes. We confirm that the most optimal mass ratio of nanoparticle/DNA is 1 : 1 by conducting a series of experiments. This work provides important experimental basis for the application of the magnetic nanoparticles on gene delivery to porcine somatic cells, which is significant for the achieving of breeding new transgenic cloned pigs by using somatic cell nuclear transfer technique.
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Mohamed, Nather Ibraheem, Salma M. Hassan, and Khaleed J. Khalil. "Preparation, Characterization, and Antimicrobial Activity of Polyaniline and Fe2O3/Polyaniline Composite Nanoparticle." Iraqi Journal of Physics (IJP) 20, no. 1 (March 1, 2022): 48–56. http://dx.doi.org/10.30723/ijp.v20i1.725.
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An oxidative polymerization approach was used to create polyaniline (PANI) and Fe2O3 /PANI nanoparticle combination. Various characterization approaches were used to investigate the structural, morphological, and Fe2O3 /PANI nanoparticle structures. The findings support the synthesis of polycrystalline nanoparticle PANI and Fe2O3 /PANI spherical nanoparticle composites. Gram-positive bacteria are tested for antibacterial activity. Various quantities of Nanoparticles of PANI and Fe2O3 /PANI nanoparticle composites were used to test Staph-aureus and gram-negative bacteria, E-coli, and candida species. PANI has antibacterial properties against all microorganisms tested. Fe2O3 /PANI nanoparticle composites, on the other hand, have higher antibacterial activity, as evidenced by the zone of inhibition. Bacterial inhibition zones are in S. aureus (positive), and E. coli are in good functioning order. With increasing concentrations of Fe2O3 /PANI nanoparticle composites, the inhibition zones of all bacteria are larger. Finally, the antimicrobial activity of Fe2O3 /PANI nanoparticle composite is characterized using a simplified mechanism based on electrostatic attraction. In this paper, a conductive polymer doped with iron nanoparticles was fabricated for the aim of testing it in the field of bacterial resistance.
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Ahmed-Cox, Aria, Alexander M. Macmillan, Elvis Pandzic, Renee M. Whan, and Maria Kavallaris. "Application of Rapid Fluorescence Lifetime Imaging Microscopy (RapidFLIM) to Examine Dynamics of Nanoparticle Uptake in Live Cells." Cells 11, no. 4 (February 12, 2022): 642. http://dx.doi.org/10.3390/cells11040642.
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A key challenge in nanomedicine stems from the continued need for a systematic understanding of the delivery of nanoparticles in live cells. Complexities in delivery are often influenced by the biophysical characteristics of nanoparticles, where even subtle changes to nanoparticle designs can alter cellular uptake, transport and activity. Close examination of these processes, especially with imaging, offers important insights that can aid in future nanoparticle design or translation. Rapid fluorescence lifetime imaging microscopy (RapidFLIM) is a potentially valuable technology for examining intracellular mechanisms of nanoparticle delivery by directly correlating visual data with changes in the biological environment. To date, applications for this technology in nanoparticle research have not been explored. A PicoQuant RapidFLIM system was used together with commercial silica nanoparticles to follow particle uptake in glioblastoma cells. Importantly, RapidFLIM imaging showed significantly improved image acquisition speeds over traditional FLIM, which enabled the tracking of nanoparticle uptake into subcellular compartments. We determined mean lifetime changes and used this to delineate significant changes in nanoparticle lifetimes (>0.39 ns), which showed clustering of these tracks proximal to both extracellular and nuclear membrane boundaries. These findings demonstrate the ability of RapidFLIM to track, localize and quantify changes in single nanoparticle fluorescence lifetimes and highlight RapidFLIM as a valuable tool for multiparameter visualization and analysis of nanoparticle molecular dynamics in live cells.
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Galkin, Mikhail. "Application of cellular and artificial membranes in nanomedicine." Vestnik of Saint Petersburg University. Medicine 15, no. 4 (2020): 290–99. http://dx.doi.org/10.21638/spbu11.2020.407.
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The use of nanoparticles in treatment and diagnostics of a number of disorders is becoming more and more popular. Further investigations are needed for improving the specificity of nanoparticle action, precisely targeted drug delivery, decreasing opsonization of nanoparticles by macrophages. Numerous ways of nanoparticle surface modification have been successfully tested for increasing their therapeutic potential and reducing possible side effects. Nanoparticle encapsulation using plasma membranes of red blood cells as well as other cell types has been recently introduced. This field of translational medicine substantially expands opportunities for nanoparticle application in clinical diagnostics and therapy of cancer, cardiovascular diseases, in vaccine development etc. This review focuses on ways, advantages and disadvantages of using cellular membranes in nanomedicine. Application of artificial lipid membranes in nanoparticles encapsulation is proposed.
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Skountzos, Emmanuel N., Katerina S. Karadima, and Vlasis G. Mavrantzas. "Structure and Dynamics of Highly Attractive Polymer Nanocomposites in the Semi-Dilute Regime: The Role of Interfacial Domains and Bridging Chains." Polymers 13, no. 16 (August 16, 2021): 2749. http://dx.doi.org/10.3390/polym13162749.
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Detailed molecular dynamics (MD) simulations are employed to study how the presence of adsorbed domains and nanoparticle bridging chains affect the structural, conformational, thermodynamic, and dynamic properties of attractive polymer nanocomposite melts in the semi-dilute regime. As a model system we have chosen an unentangled poly(ethylene glycol) (PEG) matrix containing amorphous spherical silica nanoparticles with different diameters and at different concentrations. Emphasis is placed on properties such as the polymer mass density profile around nanoparticles, the compressibility of the system, the mean squared end-to-end distance of PEG chains, their orientational and diffusive dynamics, the single chain form factor, and the scattering functions. Our analysis reveals a significant impact of the adsorbed, interfacial polymer on the microscopic dynamic and conformational properties of the nanocomposite, especially under conditions favoring higher surface-to-volume ratios (e.g., for small nanoparticle sizes at fixed nanoparticle loading, or for higher silica concentrations). Simultaneously, adsorbed polymer chains adopt graft-like conformations, a feature that allows them to considerably extend away from the nanoparticle surface to form bridges with other nanoparticles. These bridges drive the formation of a nanoparticle network whose strength (number of tie chains per nanoparticle) increases substantially with increasing concentration of the polymer matrix in nanoparticles, or with decreasing nanoparticle size at fixed nanoparticle concentration. The presence of hydroxyl groups at the ends of PEG chains plays a key role in the formation of the network. If hydroxyl groups are substituted by methoxy ones, the simulations reveal that the number of bridging chains per nanoparticle decreases dramatically, thus the network formed is less dense and less strong mechanically, and has a smaller impact on the properties of the nanocomposite. Our simulations predict further that the isothermal compressibility and thermal expansion coefficient of PEG-silica nanocomposites are significantly lower than those of pure PEG, with their values decreasing practically linear with increasing concentration of the nanocomposite in nanoparticles.