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Pattabiraman, K., M. Kameswari i M. Seenivasan. "Generalized Version of <i>ISI</i> Invariant for some Molecular Structures". Materials Science Forum 1048 (4.01.2022): 221–26. http://dx.doi.org/10.4028/www.scientific.net/msf.1048.221.
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Degree related topological invariants are the bygone and most victorioustype of graph invariants so far. In this article, we are interested in finding the generalized inverse indeg invariant of the nanostar dendrimers D[r],fullerene dendrimerNS4[r], and polymer dendrimerNS5[r]. Keywords: nanotubes; inverse indeg invariant; nanostar dendrimers; fullerene dendrimer; polymer dendrimer
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Qing, Xie, Zhen Wang, Mobeen Munir i Haseeb Ahmad. "Molecular Irregularity Indices of Nanostar, Fullerene, and Polymer Dendrimers". Journal of Chemistry 2020 (28.02.2020): 1–12. http://dx.doi.org/10.1155/2020/9437612.
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Dendrimers are highly branched organic macromolecules with successive layers of branch units surrounding a central core. Some properties like toxicity, entropy, and heats of vaporization of these dendrimers can be forecasted using topological indices. The present article is devoted to study of irregularity indices of three well-known classes of dendrimers, namely, nanostar dendrimer D[p], fullerene dendrimer NS4[p], and polymer dendrimerNS5[p], where p is the step size. We also see the relation of irregularity of these dendrimers on the step size graphically.
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Singh, Aditya, i Shubhrat Maheshwari. "DENDRIMERS FOR NEURO TARGETING". International Journal of Pharma Professional’s Research (IJPPR) 14, nr 1 (3.02.2023): 124–30. http://dx.doi.org/10.48165/ijppronline.2023.14111.
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Fortunately, the system is built with established principles that create a wide safety margin, making failure an occurrence with a low chance. The mechanical behaviour of the structure is numerically modelled in an effort to accurately reproduce the real response because it is difficult to assess such a probability level in an efficient manner. However, as the complexity of the numerical model is increased in an effort to increase accuracy and take specific mechanical behaviour into account, the model tends to become more time-consuming. Dendrimers are molecules with repeated branches that have a spherical three-dimensional appearance and form the centre of dendrimers. The drug molecules can be connected to the surface of the dendrimer and its sprouting branches in a structure termed a dendron, which is the dendrimer's sole functional unit. Dendrimers can be categorised by their generation number, which ranges from G0.5 to G5, depending on how they grow. Dendrimers come in a variety of forms, with some having significant uses in the administration of drugs, such as poly(amidoamine) (PAMAM) dendrimers, poly(propylene imine) (PPI) dendrimers, polyether copolyester (PEPE) dendrimers, PEGylated dendrimers, and peptide dendrimers. Dendrimers have an architecture that depends on things like sizes, forms, surface chemistries, stiffness or flexibility, architecture, or interior elemental compositions. This article provides an overview of a comprehensive and effective product design framework that supports concurrent dendrimer design optimization applications.
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Bober, Zuzanna, Dorota Bartusik-Aebisher i David Aebisher. "Application of Dendrimers in Anticancer Diagnostics and Therapy". Molecules 27, nr 10 (18.05.2022): 3237. http://dx.doi.org/10.3390/molecules27103237.
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The application of dendrimeric constructs in medical diagnostics and therapeutics is increasing. Dendrimers have attracted attention due to their compact, spherical three-dimensional structures with surfaces that can be modified by the attachment of various drugs, hydrophilic or hydrophobic groups, or reporter molecules. In the literature, many modified dendrimer systems with various applications have been reported, including drug and gene delivery systems, biosensors, bioimaging contrast agents, tissue engineering, and therapeutic agents. Dendrimers are used for the delivery of macromolecules, miRNAs, siRNAs, and many other various biomedical applications, and they are ideal carriers for bioactive molecules. In addition, the conjugation of dendrimers with antibodies, proteins, and peptides allows for the design of vaccines with highly specific and predictable properties, and the role of dendrimers as carrier systems for vaccine antigens is increasing. In this work, we will focus on a review of the use of dendrimers in cancer diagnostics and therapy. Dendrimer-based nanosystems for drug delivery are commonly based on polyamidoamine dendrimers (PAMAM) that can be modified with drugs and contrast agents. Moreover, dendrimers can be successfully used as conjugates that deliver several substances simultaneously. The potential to develop dendrimers with multifunctional abilities has served as an impetus for the design of new molecular platforms for medical diagnostics and therapeutics.
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Richter-Egger, Dana L., Hong Li i Sheryl A. Tucker. "Spectroscopic Investigations of Polyamido Amine Starburst Dendrimers with Reichardt's ET-30 Dye". Applied Spectroscopy 54, nr 8 (sierpień 2000): 1151–56. http://dx.doi.org/10.1366/0003702001950959.
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The association between Reichardt's ET-30 dye and amine- and carboxylate-terminated polyamido amine (PAMAM) dendrimers was investigated and shown to be different from results reported for micelles and traditional polymers. The absorption spectra illustrated that the solvatochromic, microenvironmental polarity probe associated with PAMAM dendrimers in less polar regions with a polarity comparable to 1-decanol. Model compounds that mimic PAMAMs' surface groups and branching moieties were used to better define the associated dye's location and demonstrated that ET-30 penetrated beyond the dendrimer's surface groups, into the interfacial region. Additionally, changing sample preparation methods controlled the nature and extent of the dye/dendrimer association. Under certain experimental conditions, the dye/dendrimer complexes formed large aggregates.
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Chirag M, Gowda D V, Sathish Babu i Famna Roohi N K. "A Comprehensive review on Dendrimers in current advanced Drug delivery". International Journal of Research in Pharmaceutical Sciences 11, nr 1 (5.02.2020): 1055–66. http://dx.doi.org/10.26452/ijrps.v11i1.1936.
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In this particular review, it is been noted that Dendrimers are novel three-dimensional globular nano-polymeric structure; having multiple functional groups on the surface enhances their function. Synonymous terms for dendrimer include arborols and cascade molecules. The importance of dendrimers in a large variety of fields has been detected, where the various types of dendrimers helps in various fields of drug delivery with the different types of dendrimers with the generation. Hence the dendrimer gains more attention from researchers among various nano-materials. Convenient synthesis of the structure makes them as a good nano-material for drug delivery. In recent, dendrimers showed their activity in different drug delivery systems having properties like cancer targeting, anti-bacterial, ocular drug delivery, etc.. The future direction about the dendrimers are been discussed. The present review is focused on types of dendrimers like Polypropylene Imine dendrimer (PPI), Poly(amidoamine) dendrimers (PAMAM), Poly-l-lysine dendrimers, Type of Frechet’s dendrimer, Core-shell tecto dendrimers, Chiral dendrimers, Liquid crystalline dendrimers, Peptide dendrimers, Multiple antigen peptide dendrimers, Glyco-dendrimers, Hybrid dendrimers, Polyester dendrimers in which among these type of dendrimers, the Polypropylene Imine dendrimer (PPI) and Poly(amidoamine) dendrimers are found to be good carriers for various targeting site, Dendrimers are synthesized through various methods like Divergent method, Convergent method, Hyper cores and branched monomer growth method, Double exponential growth method, Click chemistry method, recent advances in dendrimers are used in the Anti-cancer delivery, Anti-bacterial delivery, oral route delivery, pulmonary drug delivery, transdermal drug delivery, ocular delivery, and targeted drug delivery the safety aspects, and future strategies are also been discussed in the below article.
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Szota, Magdalena, Katarzyna Reczyńska-Kolman, Elżbieta Pamuła, Olga Michel, Julita Kulbacka i Barbara Jachimska. "Poly(amidoamine) Dendrimers as Nanocarriers for 5-Fluorouracil: Effectiveness of Complex Formation and Cytotoxicity Studies". International Journal of Molecular Sciences 22, nr 20 (16.10.2021): 11167. http://dx.doi.org/10.3390/ijms222011167.
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Two generations of positively charged poly(amidoamine) dendrimers (PAMAMs) were selected for study as potential carriers for the anticancer drug 5-fluorouracil (5FU), a drug primarily used in the treatment of colorectal cancer. Analytical techniques, such as UV-Vis spectrophotometry, NMR Spectroscopy and Laser Doppler Velocimetry (LDV), have shown that the most critical factor determining the formation of a PAMAM–5FU complex is the starting components’ protonation degree. The tests confirmed the system’s ability to attach about 20 5FU molecules per one dendrimer molecule for the G4PAMAM dendrimer and about 25 molecules for the G6PAMAM dendrimer, which gives a system yield of 16% for the fourth generation and 5% for sixth generation dendrimers. Additionally, using the QCM-D method, the adsorption efficiency and the number of drug molecules immobilized in the dendrimer structure were determined. A new aspect in our study was the determination of the change in zeta potential (ζ) induced by the immobilization of 5FU molecules on the dendrimer’s outer shell and the importance of this effect in the direct contact of the carrier with cells. Cytotoxicity tests (resazurin reduction and MTS tests) showed no toxicity of dendrimers against mouse fibroblast cells (L929) and a significant decrease in cell viability in the case of four human malignant cell lines: malignant melanoma (A375), glioblastoma (SNB-19), prostate cancer (Du-145) and colon adenocarcinoma (HT-29) during incubation with PAMAM–5FU complexes. The purpose of our work was to investigate the correlation between the physicochemical properties of the carrier and active substance and the system efficiency and optimizing conditions for the formation of an efficient system based on PAMAM dendrimers as nanocarriers for 5-fluorouracil. An additional aspect was to identify potential application properties of the complexes, as demonstrated by cytotoxicity tests.
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Milenin, Sergey A., Elizaveta V. Selezneva, Pavel A. Tikhonov, Viktor G. Vasil’ev, Alexander I. Buzin, Nikolay K. Balabaev, Andrey O. Kurbatov i in. "Hybrid Polycarbosilane-Siloxane Dendrimers: Synthesis and Properties". Polymers 13, nr 4 (17.02.2021): 606. http://dx.doi.org/10.3390/polym13040606.
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A series of carbosilane dendrimers of the 4th, 6th, and 7th generations with a terminal trimethylsilylsiloxane layer was synthesized. Theoretical models of these dendrimers were developed, and equilibrium dendrimer conformations obtained via molecular dynamics simulations were in a good agreement with experimental small-angle X-ray scattering (SAXS) data demonstrating molecule monodispersity and an almost spherical shape. It was confirmed that the glass transition temperature is independent of the dendrimer generation, but is greatly affected by the chemical nature of the dendrimer terminal groups. A sharp increase in the zero-shear viscosity of dendrimer melts was found between the 5th and the 7th dendrimer generations, which was qualitatively identical to that previously reported for polycarbosilane dendrimers with butyl terminal groups. The viscoelastic properties of high-generation dendrimers seem to follow some general trends with an increase in the generation number, which are determined by the regular branching structure of dendrimers.
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Bosch, Paula, Desislava Staneva, Evgenia Vasileva-Tonkova, Petar Grozdanov, Ivanka Nikolova, Rositsa Kukeva, Radostina Stoyanova i Ivo Grabchev. "New Poly(Propylene Imine) Dendrimer Modified with Acridine and Its Cu(II) Complex: Synthesis, Characterization and Antimicrobial Activity". Materials 12, nr 18 (18.09.2019): 3020. http://dx.doi.org/10.3390/ma12183020.
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A second-generation poly(propylene imine) dendrimer modified with acridine and its Cu(II) complex have been synthesized for the first time. It has been found that two copper ions form complexes with the nitrogen atoms of the dendrimeric core by coordinate bonds. The new compounds have been characterized by nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), fourier-transform infrared spectroscopy (FTIR) and fluorescence spectroscopy. The spectral characteristics of the modified dendrimer have been measured in different organic solvents, and a negative fluorescence solvatochromism has been observed. The antimicrobial activity of the dendrimers has been tested against model pathogenic microorganisms in agar and by broth dilution method. The cotton fabric treated with both dendrimers has been evaluated towards pathogenic microorganisms. The obtained modified cotton fabrics have been shown to hamper bacterial growth and to prevent biofilm formation. Dendrimer cytotoxicity has been investigated in vitro in the model HEp-2 cell line.
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Nayak, Jyoti, Pushpendra Kumar Tripathi, Navneet Kumar Verma i Jai Narayan Mishra. "Pharmaceutical Applications and Safety Review of Dendrimers". International Journal of Pharmaceutical Sciences and Nanotechnology 12, nr 4 (31.07.2019): 4565–72. http://dx.doi.org/10.37285/ijpsn.2019.12.4.1.
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This article describes the innovative approaches to overcome the cationic toxicity inherently associated with the dendrimers. A dendrimer is a macromolecule characterized by its highly branched 3D structure that provides a high degree of surface functionality and versatility. The toxicity is attributed to the interaction of surface cationic charge of dendrimers with negatively charged biological membranes in vivo. Dendrimer toxicity in biological system is generally characterized by hemolytic toxicity, cytotoxicity and hematological toxicity. To minimize this toxicity, two strategies have been utilized; first, designing and synthesis of biocompatible dendrimers; and second, masking of peripheral charge of dendrimers by surface engineering. Biocompatible dendrimers can be synthesized by employing biodegradable core and branching units or utilizing intermediates of various metabolic pathways. Dendrimer biocompatibility has been evaluated in vitro and in vivo for efficient presentation of biological performance. Neutral and negatively charged dendrimers do not interact with biological environment and hence are compatible for clinical applications as elucidated by various studies examined in this review. Chemical modification of the surface is an important strategy to overcome the toxicity problems associated with the dendrimers.
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Sorokina, Svetlana A., i Zinaida B. Shifrina. "Dendrimers as Antiamyloid Agents". Pharmaceutics 14, nr 4 (31.03.2022): 760. http://dx.doi.org/10.3390/pharmaceutics14040760.
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Dendrimer–protein conjugates have significant prospects for biological applications. The complexation changes the biophysical behavior of both proteins and dendrimers. The dendrimers could influence the secondary structure of proteins, zeta-potential, distribution of charged regions on the surface, the protein–protein interactions, etc. These changes offer significant possibilities for the application of these features in nanotheranostics and biomedicine. Based on the dendrimer–protein interactions, several therapeutic applications of dendrimers have emerged. Thus, the formation of stable complexes retains the disordered proteins on the aggregation, which is especially important in neurodegenerative diseases. To clarify the origin of these properties and assess the efficiency of action, the mechanism of protein–dendrimer interaction and the nature and driving force of binding are considered in this review. The review outlines the antiamyloid activity of dendrimers and discusses the effect of dendrimer structures and external factors on their antiamyloid properties.
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Kim, You Kyoung, In Kyu Park, Hu Lin Jiang, Rohidas B. Arote, Hwan Jeong Jeong, Eun Mi Kim, Myung Haing Cho, Hee Seung Bom i Chong Su Cho. "Glucosylated Polypropylenimine Dendrimer as a Novel Gene Carrier". Key Engineering Materials 342-343 (lipiec 2007): 457–60. http://dx.doi.org/10.4028/www.scientific.net/kem.342-343.457.
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Polypropylenimine (PPI) dendrimers have been used by many researchers as gene delivery carriers due to their high functionality. Glucose as a kind of carbohydrate is biocompatible and hydrophilic. In this study, we synthesized glucosylated PPI (G-PPI) dendrimers to reduce cytotoxicity. Glucose substitution of G-PPI dendrimers was determined by the sulfuric acid micromethod. The G-PPI dendrimer was complexed with plasmid DNA in various N/P ratios, and the complex was characterized. G-PPI dendrimers showed good DNA binding ability and high protection of DNA from nuclease attack. The G-PPI dendrimer had low cytotoxicity compared to PPI dendrimer by cytotoxicity assay. Also, transfection efficiency was influenced by glucosylation degree and the transfection efficiency for the G-PPI-5 was slightly higher than that of PPI dendrimer in HeLa cell line.
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Rajakumar, Perumal, i Devaraj Anandkumar. "Photophysical and Electrochemical Properties and Anticancer Activities of Porphyrin-Cored Fluorenodendrimers Synthesized by Click Chemistry". Synlett 29, nr 15 (14.08.2018): 1995–2000. http://dx.doi.org/10.1055/s-0037-1610218.
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A new class of porphyrin-cored fluorenodendrimers were synthesized by a convergent approach through click chemistry. The zeroth-, first-, and second-generation porphyrin-cored fluorenodendrimers were characterized by means of 1H and 13C NMR spectroscopy, UV-vis spectroscopy, fluorescent spectroscopy, elemental analysis, and MALDI-TOF mass spectrometry. The UV-vis spectrum of the dendrimers showed an increase in the absorption intensity on increasing the dendrimer generation, and a bathochromic shift was observed for higher-generation dendrimers compared with lower-generation dendrimers. The dendrimers showed emission bands at 317, 604–668, and 617–668 nm, the intensity of which increased with increasing dendrimer generation. All the synthesized dendrimers exhibited a reversible oxidation potential in cyclic voltammetry. The therapeutic efficacy of the porphyrin-cored fluorenodendrimers for the inhibition of a growth tumor cell (PA-1) increased with increasing generation number of the dendrimer.
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Sathiya Savithri, Jothinathan, i Perumal Rajakumar. "Synthesis, photophysical, antibacterial and molecular docking studies on aromatic ring core-containing rhodamine B decorated triazole bridged dendrimers". New Journal of Chemistry 42, nr 24 (2018): 19390–99. http://dx.doi.org/10.1039/c8nj02943a.
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Rhodamine B decorated dendrimers 1–6 were synthesized by a convergent approach using click chemistry. The zeroth generation dendrimer 1 (G0) and the first generation dendrimer 4 (G1) showed better antibacterial activity than the other dendrimers.
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Chis, Adriana Aurelia, Carmen Dobrea, Claudiu Morgovan, Anca Maria Arseniu, Luca Liviu Rus, Anca Butuca, Anca Maria Juncan i in. "Applications and Limitations of Dendrimers in Biomedicine". Molecules 25, nr 17 (1.09.2020): 3982. http://dx.doi.org/10.3390/molecules25173982.
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Biomedicine represents one of the main study areas for dendrimers, which have proven to be valuable both in diagnostics and therapy, due to their capacity for improving solubility, absorption, bioavailability and targeted distribution. Molecular cytotoxicity constitutes a limiting characteristic, especially for cationic and higher-generation dendrimers. Antineoplastic research of dendrimers has been widely developed, and several types of poly(amidoamine) and poly(propylene imine) dendrimer complexes with doxorubicin, paclitaxel, imatinib, sunitinib, cisplatin, melphalan and methotrexate have shown an improvement in comparison with the drug molecule alone. The anti-inflammatory therapy focused on dendrimer complexes of ibuprofen, indomethacin, piroxicam, ketoprofen and diflunisal. In the context of the development of antibiotic-resistant bacterial strains, dendrimer complexes of fluoroquinolones, macrolides, beta-lactamines and aminoglycosides have shown promising effects. Regarding antiviral therapy, studies have been performed to develop dendrimer conjugates with tenofovir, maraviroc, zidovudine, oseltamivir and acyclovir, among others. Furthermore, cardiovascular therapy has strongly addressed dendrimers. Employed in imaging diagnostics, dendrimers reduce the dosage required to obtain images, thus improving the efficiency of radioisotopes. Dendrimers are macromolecular structures with multiple advantages that can suffer modifications depending on the chemical nature of the drug that has to be transported. The results obtained so far encourage the pursuit of new studies.
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Căta, Adina, Ioana Maria Carmen Ienașcu, Mariana Nela Ştefănuț, Dan Roșu i Oana-Raluca Pop. "Properties and Bioapplications of Amphiphilic Janus Dendrimers: A Review". Pharmaceutics 15, nr 2 (9.02.2023): 589. http://dx.doi.org/10.3390/pharmaceutics15020589.
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Amphiphilic Janus dendrimers are arrangements containing both hydrophilic and hydrophobic units, capable of forming ordered aggregates by intermolecular noncovalent interactions between the dendrimer units. Compared to conventional dendrimers, these molecular self-assemblies possess particular and effective attributes i.e., the presence of different terminal groups, essential to design new elaborated materials. The present review will focus on the pharmaceutical and biomedical application of amphiphilic Janus dendrimers. Important information for the development of novel optimized pharmaceutical formulations, such as structural classification, synthetic pathways, properties and applications, will offer the complete characterization of this type of Janus dendrimers. This work will constitute an up-to-date background for dendrimer specialists involved in designing amphiphilic Janus dendrimer-based nanomaterials for future innovations in this promising field.
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González Corrales, Daniela, Nathalie Fernández Rojas, Grettel Solís Vindas, Maripaz Santamaría Muñoz, Marianela Chavarría Rojas, Daniela Matarrita Brenes, María Fernanda Rojas Salas i German Madrigal Redondo. "Dendrimers and their applications". Journal of Drug Delivery and Therapeutics 12, nr 1-S (15.02.2022): 151–58. http://dx.doi.org/10.22270/jddt.v12i1-s.5307.
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Dendrimers are symmetric molecules; their size is within the nanoscale. Its structure is usually homogeneous and monodisperse; they are composed of a nucleus and several layers 1. The number of layers that the dendrimer has defines its generation. There are different types of dendrimers. The synthesis of these macromolecules is carried out following steps of growth and activation, and organic reactions are required to obtain their branched structure2. Although size is essential, the determining factor of toxicity in dendrimers is the charge of the surface; it has been found that the higher generation dendrimers and the cationic ones are the most toxic compared to the lower generation anionics that evaluated at low concentrations did not show any toxicity 3. The dendrimers will favor the pharmacokinetics of a drug through the dendritic structure, the generation of the dendrimer to be used, the intramolecular interaction force between the adjacent functional groups in the dendrimer, the conditions of the environment such as pH, solvent polarity, strength ionic, saline concentration or presence of counterions, among others 4. Due to dendrimers' size and surface composition, the use of dendrimers in drug delivery has been increasingly studied. There are different interaction mechanisms between drugs in dendrimers, and these can be broadly divided into simple encapsulation, electrostatic interaction, and covalent bonds 5. The use of dendrimers in ocular administration has greatly impacted the complexity of this administration route. Gene therapy has also benefited from the emergence of these molecules as it facilitates targeted therapy.
Keywords: Dendrimers, Drug delivery, Gene therapy, Pharmacokinetic, Transport System
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Zhou, Kejin, Liem H. Nguyen, Jason B. Miller, Yunfeng Yan, Petra Kos, Hu Xiong, Lin Li i in. "Modular degradable dendrimers enable small RNAs to extend survival in an aggressive liver cancer model". Proceedings of the National Academy of Sciences 113, nr 3 (4.01.2016): 520–25. http://dx.doi.org/10.1073/pnas.1520756113.
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RNA-based cancer therapies are hindered by the lack of delivery vehicles that avoid cancer-induced organ dysfunction, which exacerbates carrier toxicity. We address this issue by reporting modular degradable dendrimers that achieve the required combination of high potency to tumors and low hepatotoxicity to provide a pronounced survival benefit in an aggressive genetic cancer model. More than 1,500 dendrimers were synthesized using sequential, orthogonal reactions where ester degradability was systematically integrated with chemically diversified cores, peripheries, and generations. A lead dendrimer, 5A2-SC8, provided a broad therapeutic window: identified as potent [EC50 < 0.02 mg/kg siRNA against FVII (siFVII)] in dose–response experiments, and well tolerated in separate toxicity studies in chronically ill mice bearing MYC-driven tumors (>75 mg/kg dendrimer repeated dosing). Delivery of let-7g microRNA (miRNA) mimic inhibited tumor growth and dramatically extended survival. Efficacy stemmed from a combination of a small RNA with the dendrimer’s own negligible toxicity, therefore illuminating an underappreciated complication in treating cancer with RNA-based drugs.
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Mostovaya, Olga, Igor Shiabiev, Dmitry Pysin, Alesia Stanavaya, Viktar Abashkin, Dzmitry Shcharbin, Pavel Padnya i Ivan Stoikov. "PAMAM-Calix-Dendrimers: Second Generation Synthesis, Fluorescent Properties and Catecholamines Binding". Pharmaceutics 14, nr 12 (8.12.2022): 2748. http://dx.doi.org/10.3390/pharmaceutics14122748.
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A convenient method for the synthesis of the second generation of PAMAM dendrimers based on a p-tert-butylthiacalix[4]arene core in cone, partial cone and 1,3-alternate conformations was developed. Unusual fluorescence of the obtained PAMAM-calix-dendrimers has been found and explained. The binding ability of the synthesized dendrimers toward catecholamines (dopamine, L-adrenaline and L-noradrenaline) was shown by UV-Vis, fluorescence, 1D and 2D NMR spectroscopy and the binding constants (logKa 3.85–4.74) calculated. As was shown, the PAMAM-calix-dendrimers bind catecholamines by the internal cavities. All the studied hormones were most efficiently bound by the dendrimers bearing a macrocyclic core in 1,3-alternate conformation. The size of the formed supramolecular systems of dendrimer/catecholamine was established by the DLS method. A decrease in hemolytic activity of the PAMAM-calix-dendrimers with an increase in the generation number of a dendrimer was shown for the dendrimers with a core in 1,3-alternate conformation. The prospects for the use of the synthesized dendrimers with the macrocyclic core as drug delivery agents were discussed.
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Das, Sanjita, Rohan Verma i Vikash Chauhan. "DENDRIMERS IN NOVEL DRUG DELIVERY SYSTEM: AN UPDATED REVIEW". Suranaree Journal of Science and Technology 30, nr 6 (6.02.2024): 070070(1–12). http://dx.doi.org/10.55766/sujst-2023-06-e01194.
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Nanoscale molecules known as dendrimers possess clearly defined, uniform, and monodisperse structures. They’re composed of a symmetrical core with an outside and interior shell. Due to their multiple beneficial features, dendrimers are an excellent choice in the medical field; this page compiles all of their different uses. Many different kinds of poly (propylene imine) and poly (amidoamine) dendrimers integrated with imatinib, sunitinib, cisplatin, melphalan, doxorubicin, paclitaxel, and methotrexate have shown advantages over the drug molecule alone. Dendrimers have undergone extensive research for their potential as anti-cancer agents. The mainstay of the inflammatory medicine was dendrimer complexes of indomethacin, piroxicam, ketoprofen ibuprofen, and diflunisal. Given the circumstances, the growth of bacterial strains resilient to antibiotics, fluoroquinolone, macrolide, beta-lactamine, and aminoglycoside dendrimer complexes have shown positive outcomes. In relation to treatment with antiviral drugs, There has been a study to create dendrimers being conjugated with tenofovir, maraviroc, zidovudine, oseltamivir, and other antivirals. Additionally, dendrimers have successfully allured much interest in cardiovascular medicine. Large, multi-component macromolecules constitute dendrimers. The present review enlists all kinds of related scientific and valuable aspects of dendrimers to help the researcher working with dendrimers.
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Ozerin, A. N., D. I. Svergun, V. V. Volkov, A. I. Kuklin, V. I. Gordelyi, A. Kh Islamov, L. A. Ozerina i D. S. Zavorotnyuk. "The spatial structure of dendritic macromolecules". Journal of Applied Crystallography 38, nr 6 (12.11.2005): 996–1003. http://dx.doi.org/10.1107/s0021889805032115.
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A low-resolutionab initioshape determination was performed from small-angle neutron and X-ray scattering (SANS and SAXS) curves from solutions of polycarbosilane dendrimers with the three-functional and the four-functional branching centre of the fourth, fifth, sixth, seventh and eighth generations. In all cases, anisometric dendrimer shapes were obtained. The overall shapes of the dendrimers with the three- and four-functional branching centres were oblate ellipsoids of revolution and triaxial ellipsoids, respectively. The restored bead models revealed a pronounced heterogeneity within the dendrimer structure. The density deficit was observed in the central part and close to the periphery of the dendrimers. The fraction of the overall volume of the dendrimers available for solvent penetration was about 0.2–0.3. These results may help in the design of new practical applications of dendrimer macromolecules.
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Mikhtaniuk, Sofia, Valeriy Bezrodnyi, Oleg Shavykin, Igor Neelov, Nadezhda Sheveleva, Anastasia Penkova i Denis Markelov. "Comparison of Structure and Local Dynamics of Two Peptide Dendrimers with the Same Backbone but with Different Side Groups in Their Spacers". Polymers 12, nr 8 (25.07.2020): 1657. http://dx.doi.org/10.3390/polym12081657.
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In this paper, we perform computer simulation of two lysine-based dendrimers with Lys-2Lys and Lys-2Gly repeating units. These dendrimers were recently studied experimentally by NMR (Sci. Reports, 2018, 8, 8916) and tested as carriers for gene delivery (Bioorg. Chem., 2020, 95, 103504). Simulation was performed by molecular dynamics method in a wide range of temperatures. We have shown that the Lys-2Lys dendrimer has a larger size but smaller fluctuations as well as lower internal density in comparison with the Lys-2Gly dendrimer. The Lys-2Lys dendrimer has larger charge but counterions form more ion pairs with its NH 3 + groups and reduce the bare charge and zeta potential of the first dendrimer more strongly. It was demonstrated that these differences between dendrimers are due to the lower flexibility and the larger charge (+2) of each 2Lys spacers in comparison with 2Gly ones. The terminal CH2 groups in both dendrimers move faster than the inner CH2 groups. The calculated temperature dependencies of the spin-lattice relaxation times of these groups for both dendrimers are in a good agreement with the experimental results obtained by NMR.
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Kurbatov, Andrey O., Nikolay K. Balabaev, Kirill A. Litvin i Elena Yu Kramarenko. "Structure and Mechanical Response of Polybutylcarbosilane Dendrimers Confined in a Flat Slit: Effect of Molecular Architecture and Generation Number". Polymers 15, nr 20 (10.10.2023): 4040. http://dx.doi.org/10.3390/polym15204040.
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Due to the absence of specific interactions, carbosilane dendrimers are ideal models to study the effect of a hyperbranched regular structure on the molecular response to external influences. In this work, we have studied the conformational behavior of single polybutylcarbosilane dendrimers under confinement between impermeable flat surfaces using atomistic molecular dynamics simulations. Dendrimers of different generations belonging to two homologous series with a tetra-functional core and three- and four-functional branches were simulated. The analysis of the dependence of the internal energy of the dendrimers on the wall distance allowed us to determine the critical degree of compression at which the dendrimers are able to change their shape without energy loss. The effects of generation number and branching functionality on the number of wall contacts, density distribution and shape changes were elucidated. It was found that for high generation dendrimers, the inner layers are not accessible for external interaction. It was shown that the excess stresses occurring at high compressions are concentrated in the structural center of the dendrimer. The nature of the elastic response, which is strongly nonlinear, was analyzed at different compressions depending on the dendrimer architecture and generation. We believe that our results are useful for further studies of dendrimer films under compression and can also serve as a basis for developing model concepts to describe the dynamics of dendrimer melts.
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Sheveleva, Nadezhda N., Andrei V. Komolkin i Denis A. Markelov. "Molecular dynamics simulation of mechanical relaxation of poly(propyleneimine) dendrimers". Journal of Rheology 68, nr 1 (20.12.2023): 71–81. http://dx.doi.org/10.1122/8.0000723.
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We report on shear-stress relaxation of melts of poly(propyleneimine) (PPI) dendrimers of different generations (G2–G5). The aim of this study was to confirm our previous conclusion in Sheveleva et al. [Phys. Chem. Chem. Phys. 24, 13049–13056 (2022)] for carbosilane dendrimers that an impenetrable inner region leads to the manifestation of the crowded environment effect. The systems of PPI dendrimer melts are studied using atomistic molecular dynamics simulations. The time and frequency dependencies of the dynamic shear-stress modulus are investigated. The results are in good agreement with the available rheological experimental data for G2–G4 PPI. We have found that the crowded environment effect does not manifest itself in the mechanical relaxation of G4 PPI dendrimers in contrast to G4 carbosilane dendrimers. Despite their similar topology and close sizes, G4 PPI does not form an impenetrable core. The G5 PPI dendrimer has an impenetrable inner region, and the crowded environment effect is observed. As in carbosilane dendrimers, the maximal time of mechanical relaxation is increased due to the crowded environment effect. However, the opposite situation is for the rotational diffusion of the G5 PPI dendrimers. In contrast to carbosilane dendrimers, the rotational mobility of G5 PPI significantly slows down even taking into account the increase in the dendrimer size. The hydrogen bonding between PPI dendrimers affects the mechanical relaxation at high frequencies (short times) and enhances with growing G.
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Ashrafi, Frydon, Tahereh Mahbobi i Ashraf Sadat Ghasemi. "Computational study adsorption of mercaptopurine in generation G3 and G5 PAMAM dendrimers". Ciência e Natura 37 (21.12.2015): 12. http://dx.doi.org/10.5902/2179460x20822.
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Due to its unique properties of dendrimers as well as with high-level groups, a special ability to carry drugs. In this study compared the interaction between the two generations of poly (amidoamine) PAMAM (G3and G5) dendrimers and the drug 6-mercaptopurine (6-MP) and the drug entrapment within the structure of dendrimers the electrostatic and covalent complexation of drugs to the dendrimer surface have been studied. The use of drug-dendrimer complex enhanced drug solubility and bioavailability of the drug.
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Ficker, Mario, Valentina Paolucci i Jørn B. Christensen. "Improved large-scale synthesis and characterization of small and medium generation PAMAM dendrimers". Canadian Journal of Chemistry 95, nr 9 (wrzesień 2017): 954–64. http://dx.doi.org/10.1139/cjc-2017-0108.
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Dendrimers are promising polymers for biomedical applications; however, most dendrimer formulations have failed to move from laboratory science to upscaled products for preclinical testing or GMP production. This publications reports on an improved large-scale PAMAM dendrimer synthesis that is suitable to manufacture large amounts of highly pure and monodisperse dendrimers of generations G0–G5. Furthermore, an extended analytical guideline how to characterize PAMAM dendrimers with NMR, HPLC, SEC-MALS, ESI, MALDI, UV–vis, fluorescence, and IR spectroscopy is provided.
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Rajakumar, Perumal, Nagarathinam Venkatesan, Karuppannan Sekar, Subramani Nagaraj i Ramasamy Rengasamy. "Synthesis, Optical, and Antioxidant Studies of Anthraquinone-core-based Dendrimers with N-Phenylcarbazole as Surface Group". Australian Journal of Chemistry 67, nr 4 (2014): 636. http://dx.doi.org/10.1071/ch13521.
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Synthesis of hyperbranched dendrimers up to third generation with N-phenylcarbazole as surface group and anthraquinone as the core unit has been achieved. The fluorescence decay studies of the dendrimers indicate that generation growth alters the relaxation time. The highly branched third-generation dendrimer has a longer relaxation time than the zero-, first-, and second-generation dendrimers. Similarly, higher-generation dendrimers show better antioxidant behaviour with 1,1-diphenyl-2-picryl hydrazyl than the lower-generation dendrimers.
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Poudel, Dhruba P., i Richard T. Taylor. "Synthesis of Fluorescent, Dumbbell-Shaped Polyurethane Homo- and Heterodendrimers and Their Photophysical Properties". International Journal of Molecular Sciences 24, nr 2 (14.01.2023): 1662. http://dx.doi.org/10.3390/ijms24021662.
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Fluorescent dendrimers have wide applications in biomedical and materials science. Here, we report the synthesis of fluorescent polyurethane homodendrimers and Janus dendrimers, which often pose challenges due to the inherent reactivity of isocyanates. Polyurethane dendrons (G1–G3) were synthesized via a convergent method using a one-pot multicomponent Curtius reaction as a crucial step to establish urethane linkages. The alkyne periphery of the G1–G3 dendrons was modified by a copper catalyzed azide–alkyne click reaction (CuAAC) to form fluorescent dendrons. In the reaction of the surfaces functionalized two different dendrons with a difunctional core, a mixture of three dendrimers consisting of two homodendrimers and a Janus dendrimer were obtained. The Janus dendrimer accounted for a higher proportion in the products’ distribution, being as high as 93% for G3. The photophysical properties of Janus dendrimers showed the fluorescence resonance energy transfer (FRET) from one to the other fluorophore of the dendrimer. The FRET observation accompanied by a large Stokes shift make these dendrimers potential candidates for the detection and tracking of interactions between the biomolecules, as well as potential candidates for fluorescence imaging.
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Sheveleva, Nadezhda N., Irina I. Tarasenko, Mikhail A. Vovk, Mariya E. Mikhailova, Igor M. Neelov i Denis A. Markelov. "NMR Studies of Two Lysine Based Dendrimers with Insertion of Similar Histidine-Arginine and Arginine-Histidine Spacers Having Different Properties for Application in Drug Delivery". International Journal of Molecular Sciences 24, nr 2 (4.01.2023): 949. http://dx.doi.org/10.3390/ijms24020949.
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In this paper we study two lysine-based peptide dendrimers with Lys-His-Arg and Lys-Arg-His repeating units and terminal lysine groups. Combination of His and Arg properties in a dendrimer could be important for biomedical applications, especially for prevention of dendrimer aggregation and for penetration of dendrimers through various cell membranes. We describe the synthesis of these dendrimers and the confirmation of their structure using 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy. NMR spectroscopy and relaxation are used to study the structural and dynamic properties of these macromolecules and to compare them with properties of previously studied dendrimers with Lys-2Arg and Lys-2His repeating units. Our results demonstrate that both Lys-His-Arg and Lys-Arg-His dendrimers have pH sensitive conformation and dynamics. However, properties of Lys-His-Arg at normal pH are more similar to those of the more hydrophobic Lys-2His dendrimer, which has tendency towards aggregation, while the Lys-Arg-His dendrimer is more hydrophilic. Thus, the conformation with the same amino acid composition of Lys-His-Arg is more pH sensitive than Lys-Arg-His, while the presence of Arg groups undoubtedly increases its hydrophilicity compared to Lys-2His. Hence, the Lys-His-Arg dendrimer could be a more suitable (in comparison with Lys-2His and Lys-Arg-His) candidate as a pH sensitive nanocontainer for drug delivery.
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Liu, Jie, Warren D. Gray, Michael E. Davis i Ying Luo. "Peptide- and saccharide-conjugated dendrimers for targeted drug delivery: a concise review". Interface Focus 2, nr 3 (21.03.2012): 307–24. http://dx.doi.org/10.1098/rsfs.2012.0009.
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Dendrimers comprise a category of branched materials with diverse functions that can be constructed with defined architectural and chemical structures. When decorated with bioactive ligands made of peptides and saccharides through peripheral chemical groups, dendrimer conjugates are turned into nanomaterials possessing attractive binding properties with the cognate receptors. At the cellular level, bioactive dendrimer conjugates can interact with cells with avidity and selectivity, and this function has particularly stimulated interests in investigating the targeting potential of dendrimer materials for the design of drug delivery systems. In addition, bioactive dendrimer conjugates have so far been studied for their versatile capabilities to enhance stability, solubility and absorption of various types of therapeutics. This review presents a brief discussion on three aspects of the recent studies to use peptide- and saccharide-conjugated dendrimers for drug delivery: (i) synthesis methods, (ii) cell- and tissue-targeting properties and (iii) applications of conjugated dendrimers in drug delivery nanodevices. With more studies to elucidate the structure–function relationship of ligand–dendrimer conjugates in transporting drugs, the conjugated dendrimers hold promise to facilitate targeted delivery and improve drug efficacy for discovery and development of modern pharmaceutics.
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Abd-El-Aziz, Alaa S., Ebtehal G. El-Ghezlani i Amani A. Abdelghani. "Design of Organoiron Dendrimers Containing Paracetamol for Enhanced Antibacterial Efficacy". Molecules 25, nr 19 (2.10.2020): 4514. http://dx.doi.org/10.3390/molecules25194514.
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Paracetamol (acetaminophen) is a common painkiller and antipyretic drug used globally. Attachment of paracetamol to a series of organoiron dendrimers was successfully synthesized. The aim of this study is to combine the benefits of the presence of these redox-active organoiron dendrimers, their antimicrobial activities against some human pathogenic Gram-positive, and the therapeutic characteristics of paracetamol. The antimicrobial activity of these dendrimers was investigated and tested with a minimum inhibitory concentration and this has been reported. Some of these newly synthesized dendrimers exhibited the highest inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), and Staphylococcus warneri compared to reference drugs. The results of this study indicate that the antimicrobial efficacy of the dendrimers is dependent on the size of the redox-active organoiron dendrimer and its terminal functionalities. The best result has been recorded for the fourth-generation dendrimer 11, which attached to 48 paracetamol end groups and has 90 units composed of the η6-aryl-η5-cyclopentadienyliron (II) complex. This dendrimer presented inhibition of 50% of the growth (IC50) of 0.52 μM for MRSA, 1.02 μM for VRE, and 0.73 μM for Staphylococcus warneri. The structures of the dendrimers were characterized by elemental analysis, Fourier transform infrared (FT-IR), nuclear magnetic resonance (1H-NMR), and 13C-NMR spectroscopic techniques. In addition, all synthesized dendrimers displayed good thermal stability in the range of 300–350 °C following the degradation of the cationic iron moieties which occurred around 200 °C.
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Movahedi, Fateme, Mohamad Hadi Akhbari i Roslan Hasni. "Computing the Hosoya Index of Some Nanostar Dendrimers". Malaysian Journal of Fundamental and Applied Sciences 20, nr 3 (26.06.2024): 588–96. http://dx.doi.org/10.11113/mjfas.v20n3.3297.
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Dendrimers are highly branched macromolecules built up from a monomer, with new branches added in steps until a tree structure is created. The various biological characteristics of dendrimers are a good choice in chemistry, biology, the medical field, and nano-science. A topological index is a type of molecular descriptor that is calculated based on the molecular graph of a chemical structure. The Hosoya index is a well-known topological index that is used to predict some of their physico-chemical properties from the structure of molecules. The Hosoya index of a graph is defined as the total number of its independent edge sets. In this paper, we study the Hosoya index of some families of nanostar dendrimers. We obtain the formulas of the Hosoya index for two infinite classes of dendrimers, namely, nanostar dendrimer and tetrathiafulvalene dendrimer. We use the Mathematica program to evaluate the results and accuracy of calculations. Our results can be used in analyzing the molecular topology of these families of nanostar dendrimers.
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Ray, Ankur, i Sabiha Khan. "Convergent Synthesis of Novel Mono- and Di-substituted 1,2-Isopropylideneglucofuranose Appended Dendrimers with a Ferrocene Core and their Electrochemical Studies". Synlett 29, nr 10 (10.04.2018): 1367–72. http://dx.doi.org/10.1055/s-0037-1609490.
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Ferrocene-cored dendrimers incorporating 1,2-isopropylidenefuranose capped furanoside branches were synthesized and their electrochemical properties were studied. It was observed that the dendritic environment in the ferrocene dendrimers increased the E 1/2 values with increase in bulk of the dendrimer, as expected. The reversible nature of the redox process was maintained in all the dendrimers.
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Sabirov, Denis, Alina Tukhbatullina i Igor Shepelevich. "Information Entropy of Regular Dendrimer Aggregates and Irregular Intermediate Structures". Liquids 1, nr 1 (5.03.2021): 25–35. http://dx.doi.org/10.3390/liquids1010002.
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Dendrimer molecules and aggregates are chemical structures with regular branching that underlies their physicochemical properties. Regular dendrimers have been studied both theoretically and experimentally, but the irregular intermediate structures between the dendrimers of neighboring generations have not. In the present work, dendrimer aggregates, both regular and intermediate, are investigated in terms of the information entropy approach. As found, the information entropy of the regular dendrimer asymptotically increases with the generation number; herewith, its maximal value equals 2. The intermediate structures have been studied for the growing dendrimer G1 → G2 → G3 → G4 with the tricoordinated building block. The plot of the information entropy of the growing dendrimer on the size has the frontier consisting of the lowest values that correspond to the regular and irregular structures described with the symmetrical graphs. Other intermediate structures have information entropies higher than the regular dendrimers. Thus, to move the system from one informationally stable state to another, its information capacity must be temporarily increased.
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Dwivedi, Nitin, Balak Das Kurmi, Prashant Kesharwani i Jigna Shah. "GENERATION DEPENDENT TARGETING POTENTIAL OF DONEPEZIL LOADED POLY (PROPYLENEIMINE) DENDRIMER THROUGH GOAT NASAL MUCOSA". International Journal of Pharmacy and Pharmaceutical Sciences 10, nr 12 (1.12.2018): 80. http://dx.doi.org/10.22159/ijpps.2018v10i12.29912.
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Objective: In the domain of nano drug delivery, dendrimers are the most explored bioactive polymeric carrier system. The present work was aimed to study the diffusion potential of different generations of Poly (propyleneimine) (PPI) dendrimers on goat nasal mucosa in an ex vivo study and synthesize a stable dendrimer for olfactory drug delivery.Methods: The generations (3.0G, 4.0G, and 5.0G) of PPI dendrimer were synthesized, and PEGylated by MPEG 5000 and then loaded with donepezil. A comparative study was carried out among all generations in term of their drug loading capacity, stability, sustained release behaviour as well as for targeting efficacy. An ex-vivo study was carried out on Franz Diffusion Cell with goat nasal mucosa.Results: The developed G3, G4, and G5 dendrimerformulations had entrapment efficiency of 24.33±0.56%, 40.12±0.62%, and 60.4±0.6%, respectively. The nasal diffusion study revealed that 5.0G PPI dendrimer increased diffusion of donepezil up to 47% as compared to the pure solution of donepezil while 10% improvement in diffusion was seen as compared to 4.0 G PPI dendrimer. Thus obtained results claimed that the drug loading as well as targeting potential of PPI dendrimers increased with the increase in the number of generation. The investigation outcome indicated promising results of 5.0G PPI dendrimer over the 3.0G and 4.0G PPI dendrimer generations for their drug loading capacity, stability, and sustained release action.Conclusion: The 5.0G PPI dendrimer proved its superior candidature over the other lower generations of PPI dendrimers for drug delivery and drug targeting.
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Salamończyk, Grzegorz M. "A Fast and Convenient Synthesis of New Water-Soluble, Polyanionic Dendrimers". Molecules 26, nr 16 (6.08.2021): 4754. http://dx.doi.org/10.3390/molecules26164754.
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Reasonably simple, efficient, and possessing aspects of generality, the methodology for the synthesis of new, water-soluble, dendrimeric polyesters with great potential applications as antiviral drugs in their own right is described. The essential aspect of the presented approach is a quite unique, immediate access to the polyanionic material at each generation during divergent synthesis. Six target polyanionic dendrimers (generations 1, 2, and 3) have been synthesized. The key monomers applied in this project were 1,3,5-benzenetricarboxylic acid derivatives, which also worked as direct precursors of the charged dendrimer surface.
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Chen, Junjie, i Mark M. Banaszak Holl. "Dendrimer and dendrimer–conjugate protein complexes and protein coronas". Canadian Journal of Chemistry 95, nr 9 (wrzesień 2017): 903–6. http://dx.doi.org/10.1139/cjc-2017-0198.
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Dendrimers and dendrimer conjugates are widely employed for biological applications such as bio-imaging and drug delivery. Understanding the interaction between dendrimers and their biological environment is key to evaluating the efficacy and safety of these materials. Proteins can form an adsorbed layer, termed a “protein corona”, on dendrimers in either a non-specific or specific fashion. A tight-binding, non-exchangeable corona is defined as a “hard” corona, whereas a loosely bound, highly exchangeable corona is called a “soft” corona. Recent research indicates that small molecules conjugated to the polymer surface can induce protein structural change, leading to tighter protein–dendrimer binding and further protein aggregation. This “triggered” corona formation on dendrimer and dendrimer conjugates is reviewed and discussed along with the existing hard or soft corona model. This review describes the triggered corona model to further the understanding of protein corona formation.
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Laipniece, Lauma, i Valdis Kampars. "Synthesis and Thermal Properties of Azobenzene Core Polyester Dendrimers with Trityl Groups at the Periphery". Key Engineering Materials 762 (luty 2018): 171–75. http://dx.doi.org/10.4028/www.scientific.net/kem.762.171.
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We have synthesized polyester type dendrimers containing azobenzene chromophore in the core and trityl groups at the periphery using divergent growth strategy up to 3rdgeneration. We analyzed dendrimer samples using NMR, HPLC, TG, DSC and UV-Vis techniques. We found out that functionalization of dendrimer periphery is not complete. Dendrimers with trityl groups at the periphery have glass transition temperatures in the range 73-87 °C.
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MAJEED, Haza Satar. "PARAMETRIC OPTIMIZATION OF DYES ABSORPTION USING POLYPROPYLENE IMINE DENDRIMER FROM TEXTILE WASTEWATER". MINAR International Journal of Applied Sciences and Technology 04, nr 02 (1.06.2022): 217–23. http://dx.doi.org/10.47832/2717-8234.11.25.
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Recently, Dendrimers are famous for monodispersed, highly branched, three dimensional, macromolecular nanoscopic architecture with several groups of the reactive end. Dendrimers work as dye removal agents from the two systems liquid-solid or liquid-liquid. This study tackles the textile dyes removal from aqueous solutions by Reactive Black 5 (RB5), Acid Blue 7 (AB7), Reactive Red 198 (RR198), Acid Green 25 (AG25), poly (propylene imine) dendrimer (PPI). and have been utilized as model dyes. Operational parameters influence the removal of dye like the concentration of dye, the concentration of dendrimer, pH, time, and temperature were investigated. Findings revealed that the efficiency of dye removal was maximized by increasing both concentrations of dye and dendrimers. Furthermore, results showed that the adsorption of dyes was supported by acidic pH through dendrimer. Besides, tests showed that maximum dyes removal were achieved at time 16h and temperature around 60 °C. As the data revealed, it can be concluded that dendrimers are adsorbent which is environmentally friendly with somehow big adsorption ability of could be an advisable substitute for dyes elimination from coloured textile wastewater.
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Sowinska, Marta, Maja Morawiak, Marta Bochyńska-Czyż, Andrzej Lipkowski, Elżbieta Ziemińska, Barbara Zabłocka i Zofia Urbanczyk-Lipkowska. "Molecular Antioxidant Properties and In Vitro Cell Toxicity of the p-Aminobenzoic Acid (PABA) Functionalized Peptide Dendrimers". Biomolecules 9, nr 3 (5.03.2019): 89. http://dx.doi.org/10.3390/biom9030089.
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Background: Exposure to ozone level and ultraviolet (UV) radiation is one of the major concerns in the context of public health. Numerous studies confirmed that abundant free radicals initiate undesired processes, e.g. carcinogenesis, cells degeneration, etc. Therefore, the design of redox-active molecules with novel structures, containing radical quenchers molecules with novel structures, and understanding their chemistry and biology, might be one of the prospective solutions. Methods: We designed a group of peptide dendrimers carrying multiple copies of p-aminobenzoic acid (PABA) and evaluated their molecular antioxidant properties in 1,1’-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) tests. Cytotoxicity against human melanoma and fibroblast cells as well as against primary cerebral granule cells (CGC) alone and challenged by neurotoxic sodium glutamate and production of reactive oxygen species (ROS) in presence of dendrimers were measured. Results: PABA-terminated dendrimers express enhanced radical and radical cation scavenging properties in relation to PABA alone. In cellular tests, the dendrimers at 100 M fully suppress and between 20–100 M reduce proliferation of the human melanoma cell line. In concentration 20 M dendrimers generate small amount of the reactive oxygen species (<25%) but even in their presence human fibroblast and mouse cerebellar granule cells remain intact Moreover, dendrimers at 0.2–20 µM concentration (except one) increased the percentage of viable fibroblasts and CGC cells treated with 100 M glutamate. Conclusions: Designed PABA-functionalized peptide dendrimers might be a potential source of new antioxidants with cationic and neutral radicals scavenging potency and/or new compounds with marked selectivity against human melanoma cell or glutamate-stressed CGC neurons. The scavenging level of dendrimers depends strongly on the chemical structure of dendrimer and the presence of other groups that may be prompted into radical form. The present studies found different biological properties for dendrimers constructed from the same chemical fragments but the differing structure of the dendrimer tree provides once again evidence that the structure of dendrimer can have a significant impact on drug–target interactions.
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Abd-El-Aziz, Alaa S., Maysun R. Benaaisha, Amani A. Abdelghani, Rabin Bissessur, Laila H. Abdel-Rahman, Ahmed M. Fayez i Doaa Abou El-ezz. "Aspirin-Based Organoiron Dendrimers as Promising Anti-Inflammatory, Anticancer, and Antimicrobial Drugs". Biomolecules 11, nr 11 (22.10.2021): 1568. http://dx.doi.org/10.3390/biom11111568.
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Designing nanocarriers with actions directed at a specific organ or tissue is a very promising strategy since it can significantly reduce the toxicity of a bioactive drug. In this study, an organometallic dendrimer was used to synthesize a biocompatible drug delivery system by attaching aspirin to the periphery of the dendrimer. Our goal is to enhance the bioavailability and anticancer activity of aspirin and reduce its toxicity through successive generations of organoiron dendrimers. The biological activity of aspirin-based dendrimer complexes was evaluated. The result of antimicrobial activity of the synthesized dendrimers also demonstrated an increase in their antimicrobial activity with increased generation of the dendrimers for most types of microorganisms. This study reveals for the first time that organoiron dendrimers linked with aspirin exhibit an excellent Gram-negative activity comparable to the reference drug Gentamicin. All synthesized dendrimers were tested for their anticancer activity against breast cancer cell lines (MCF-7), hepatocellular cell lines (Hep-G2), and a non-cancer cell line, Human Embryonic Kidney (HEK293), using the MTT cell viability assay and compared against a standard anticancer drug, Doxorubicin. Compounds G3-D9-Asp and G4-D12-Asp exhibited noticeable activity against both cell lines, both of which were more effective than aspirin itself. In addition, the in vivo anti-inflammatory activity and histopathology of swollen paws showed that the designed aspirin-based dendrimers displayed significant anti-inflammatory activity; however, G2-D6-Asp showed the best anti-inflammatory activity, which was more potent than the reference drug aspirin during the same period. Moreover, the coupling of aspirin to the periphery of organoiron dendrimers showed a significant reduction in the toxicity of aspirin on the stomach.
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Karanjavkar, J., S. Rathod i A. Dhumal. "Dendrimer: a novel approach for drug delivery systems". Indian Journal of Pharmaceutical and Biological Research 4, nr 03 (30.09.2016): 39–49. http://dx.doi.org/10.30750/ijpbr.4.3.6.
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Dendrimers are hyper-branched macromolecules having tree like structure, consisting of a core molecule and alternating layers of monomers. So they can be synthesized by divergent and convergent growth methods. During synthesis, properties of dendrimers like dendrimer size, molecular mass, surface group can be controlled and configured to the desired need. Dendrimers have the ability to encapsulate and bind the guest molecule can be used for solubility enhancement, sustained release and various drug delivery applications. The reflections on biomedical and industrial applications of dendrimers given in this report clearly demonstrate the potential the class of polymer architecture and indeed substantiate the high hopes for the future of dendrimers.
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Baker, James R. "Dendrimer-based nanoparticles for cancer therapy". Hematology 2009, nr 1 (1.01.2009): 708–19. http://dx.doi.org/10.1182/asheducation-2009.1.708.
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AbstractRecent work has suggested that nanoparticles in the form of dendrimers may be a keystone in the future of therapeutics. The field of oncology could soon be revolutionized by novel strategies for diagnosis and therapy employing dendrimer-based nanotherapeutics. Several aspects of cancer therapy would be involved. Diagnosis using imaging techniques such as MRI will be improved by the incorporation of dendrimers as advanced contrast agents. This might involve novel contrast agents targeted specifically to cancer cells. Dendrimers can also be being applied to a variety of cancer therapies to improve their safety and efficacy. A strategy, somewhat akin to the “Trojan horse,” involves targeting anti-metabolite drugs via vitamins or hormones that tumors need for growth. Further applications of dendrimers in photodynamic therapy, boron neutron capture therapy, and gene therapy for cancer are being examined. This presentation will cover the fundamentals of research utilizing dendrimers for cancer diagnosis and therapy. An evaluation of this new technologies will detail what advantage dendrimer based therapeutics might have over conventional cancer drugs.
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Lu, Juan, Nannan Li, Yaochun Gao, Nan Li, Yifei Guo, Haitao Liu, Xi Chen, Chunyan Zhu, Zhengqi Dong i Akira Yamamoto. "The Effect of Absorption-Enhancement and the Mechanism of the PAMAM Dendrimer on Poorly Absorbable Drugs". Molecules 23, nr 8 (10.08.2018): 2001. http://dx.doi.org/10.3390/molecules23082001.
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The polyamidoamine (PAMAM) dendrimer is a highly efficient absorption promoter. In the present study, we studied the absorption-enhancing effects and the mechanism of PAMAM dendrimers with generation 0 to generation 3 (G0–G3) and concentrations (0.1–1.0%) on the pulmonary absorption of macromolecules. The absorption-enhancing mechanisms were elucidated by microarray, western blotting analysis, and PCR. Fluorescein isothiocyanate-labeled dextrans (FDs) with various molecular weights were used as model drugs of poorly absorbable drugs. The absorption-enhancing effects of PAMAM dendrimers on the pulmonary absorption of FDs were in a generation- and concentration-dependent manner. The G3 PAMAM dendrimer with high effectiveness was considered to the best absorption enhancer for improving the pulmonary absorption of FDs. G3 PAMAM dendrimers at three different concentrations were non-toxic to Calu-3 cells. Based on the consideration between efficacy and cost, the 0.1% G3 PAMAM dendrimer was selected for subsequent studies. The results showed that treatment with a 0.1% G3 PAMAM dendrimer could increase the secretion of organic cation transporters (OCTs), OCT1, OCT2, and OCT3, which might be related to the absorption-enhancing mechanisms of the pulmonary absorption of FDs. These findings suggested that PAMAM dendrimers might be potentially safe absorption enhancers for improving absorption of FDs by increasing the secretion of OCT1, OCT2, and OCT3.
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Shi, Limiao, Zhipeng Sun, Nicolas Richy, Olivier Mongin, Mireille Blanchard-Desce, Frédéric Paul i Christine O. Paul-Roth. "New Fluorescent Porphyrins with High Two-Photon Absorption Cross-Sections Designed for Oxygen-Sensitization: Impact of Changing the Connectors in the Peripheral Arms". Photochem 3, nr 3 (10.08.2023): 336–59. http://dx.doi.org/10.3390/photochem3030021.
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In the continuation of our sustained interest in porphyrin-based dendrimers and their use as luminescent photosensitizers for two-photon photodynamic therapy (2P-PDT), we wondered about the effect of changing the connectors in our macromolecular structures. We also wanted to initiate preliminary studies on meso-tetraarylporphyrins decorated with more electron-releasing arms. Thus, various meso-tetrafluorenylporphyrin-cored star-shaped and dendrimeric derivatives have been synthesized and characterized, as well as their zinc(II) complexes. In the new dendrimeric derivatives, the peripheral fluorenyl units of the dendrons are linked to the inner core either by N-phenylcarbazole (CCbz) or triphenylamine (CTpa) connectors instead of the more classic 1,3,5-phenylene (CPh) linkers previously used by us. Selected linear and non-linear optical (LO and NLO) properties were then determined for these compounds via absorption or emission studies and by two-photon excited fluorescence (TPEF) measurements. It was found that the CCbz-containing dendrimer, which has the most rigid structure, exhibits a significantly lower two-photon absorption (2PA) cross-section than its CTpa analog, presenting a more flexible structure while rather similar luminescence and singlet oxygen activation quantum yields are found for both. The origin of this unexpected discrepancy is briefly discussed based on our photophysical data. It is then demonstrated that the latter dendrimer also outperforms several closely related dendrimers in terms of 2PA action cross-section and 2PA-oxygen sensitization, making its molecular architecture quite appealing for developing new 2PA photosensitizers suited to theranostic uses.
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Kurbatov, Andrey O., Nikolay K. Balabaev, Mikhail A. Mazo i Elena Yu Kramarenko. "Adsorption of Silicon-Containing Dendrimers: Effects of Chemical Composition, Structure, and Generation Number". Polymers 13, nr 4 (13.02.2021): 552. http://dx.doi.org/10.3390/polym13040552.
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We studied the conformational behavior of silicon-containing dendrimers during their adsorption onto a flat impenetrable surface by molecular dynamics (MD) simulations. Four homologous series of dendrimers from the 4th up to the 7th generations were modeled, namely, two types of carbosilane dendrimers differing by the functionality of the core Si atom and two types of siloxane dendrimers with different lengths of the spacers. Comparative analysis of the fractions of adsorbed atoms belonging to various structural layers within dendrimers as well as density profiles allowed us to elucidate not only some general trends but also the effects determined by dendrimer specificity. In particular, it was found that in contrast to the carbosilane dendrimers interacting with the adsorbing surface mainly by their peripheral layers, the siloxane dendrimers with the longer –O–Si(CH3)2–O spacers expose atoms from their interior to the surface spreading out on it. These findings are important for the design of functional materials on the basis of silicon-containing dendrimers.
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Contin, Mario, Cybele Garcia, Cecilia Dobrecky, Silvia Lucangioli i Norma D’Accorso. "Advances in drug delivery, gene delivery and therapeutic agents based on dendritic materials". Future Medicinal Chemistry 11, nr 14 (lipiec 2019): 1791–810. http://dx.doi.org/10.4155/fmc-2018-0452.
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Dendrimers are synthetic polymers that grow in three dimensions into well-defined structures. Their morphological appearance resembles a number of trees connected by a common point. Dendritic nanoparticles have been studied for a large number of pharmaceutical and biomedical applications including gene and drug delivery, clinical diagnosis and MRI. Despite the application of dendrimers, research is still in its childhood in comparison with liposomes and other nanomaterials. They are now playing a key role in several therapeutic strategies, with dendrimer-based products in clinical trials. The aim of this review is to describe the state-of-the-art of biomedical applications of dendrimers – and dendrimer conjugates – such as drug and gene delivery and antiviral activity.
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Chen, Zhihua, Abaid ur Rehman Virk, Mustafa Habib, Tariq Javed Zia, Imran Ahmed, Ce Shi i Waqas Nazeer. "Irregularity Indices of Dendrimer Structures Used as Molecular Disrupter in QSAR Study". Journal of Chemistry 2019 (4.12.2019): 1–21. http://dx.doi.org/10.1155/2019/5371254.
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Dendrimers are rising polymeric structures known for their flexibility in medication conveyance and high usefulness, whose properties are same biomolecules. These nanostructured macromolecules have shown potential capacities in capturing as well as conjugating the high subatomic weight hydrophilic/hydrophobic substances by host-visitor collaborations and covalent holding (prodrug approach) individually. In quantitative structure-property relationships (QSPR), topological indices are utilized to gather properties of dendrimers. Topological indices catch symmetry of dendrimer structures and give it a logical reasoning to predict properties, for instance, viscosity, boiling points, the radius of gyrations, etc. In this report, we intend to examine dendrimers through irregularity indices that are valuable in QSPR studies. We studied sixteen irregularity indices if diverse dendrimer structures.
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Gajjar, Dhaval G., Rinkesh M. Patel, Hema N. Patel i Pravinkumar M. Patel. "Designing, characterization, and thermal behavior of triazine-based dendrimers". Journal of Polymer Engineering 35, nr 1 (1.01.2015): 41–52. http://dx.doi.org/10.1515/polyeng-2014-0123.
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Abstract Different generations of dendritic architecture with piperazine in core moiety and hydroxyl groups on the periphery were designed by divergent method. 1,4-biz(4,6-trichloro-1,3,5-triazin-2-yl)piperazine was synthesized as a core for dendrimer synthesis. Dendrimer was then grown to G3 from core compound using diethanolamine and cyanuric chloride as branching units. Dendrimer generations were characterized by infrared (IR) spectroscopy [Fourier transform IR (FTIR)], 1H-nuclear magnetic resonance (NMR), 13C-NMR, electrospray ionization-mass spectrometry (ESI-MS), and elemental analysis. The thermal behavior of both full- and half-generation dendrimers was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The TGA study revealed that dendrimer generations had a moderate thermal stability. Chlorine-terminated half-generation dendrimers were thermally more stable than hydroxyl-terminated full-generation dendrimers. The DSC technique was employed to determine the glass transition temperatures (Tg) of dendrimer generations. It was observed that the glass transition temperatures of synthesized dendrimer generations were of low value, which is similar to the values reported for the polyamidoamine (PAMAM) dendrimer of the same generation. It was also observed that, with the increase in the molecular weight or generation number of dendrimer, the glass transition temperature was also increased.
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STEARS, ROBIN L., ROBERT C. GETTS i STEVEN R. GULLANS. "A novel, sensitive detection system for high-density microarrays using dendrimer technology". Physiological Genomics 3, nr 2 (9.08.2000): 93–99. http://dx.doi.org/10.1152/physiolgenomics.2000.3.2.93.
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Stears, Robin L., Robert C. Getts, and Steven R. Gullans. A novel, sensitive detection system for high-density microarrays using dendrimer technology. Physiol Genomics 3: 93–99, 2000.—To improve signal detection on cDNA microarrays, we adapted a fluorescent oligonucleotide dendrimeric signal amplification system to microarray technology. This signal detection method requires 16-fold less RNA for probe synthesis, does not depend on the incorporation of fluorescent dNTPs into a reverse transcription reaction, generates a high signal-to-background ratio, and can be used to allow for multichannel detection on a single chip. Furthermore, since the dendrimers can be detected individually, it may be possible, by employing dendrimer-binding standards, to calculate the numbers of bound cDNAs can be estimated. These features make the dendrimer signal detection reagent ideal for high-throughput functional genomics research.