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1
Tang, Yuanhan, Junjie Ding, Xun Zhou, Xintao Ma, Yi Zhao, Qiyu Mu, Zixu Huang, Qian Tao, Fangjie Liu i Ling Wang. "Injectable hydrogels of enzyme-catalyzed cross-linked tyramine-modified gelatin for drug delivery". Australian Journal of Chemistry 76, nr 2 (28.02.2023): 88–99. http://dx.doi.org/10.1071/ch22188.
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Enzymatically catalyzed cross-linking is a hydrogel fabrication method that generally is considered to have lower cytotoxicity than traditional chemical cross-linking methods. In order to optimize the properties of injectable hydrogels and expand their applications, an enzyme-catalyzed cross-linked injectable hydrogel was designed. The tyramine-modified gelatin (G-T) was formed into a stable injectable hydrogel by the combination of horseradish peroxidase (HRP) and hydrogen peroxide (H2O2) catalysis. 1H NMR spectroscopy was used to demonstrate the successful modification of gelatin by tyramine. The surface morphology of the prepared hydrogels was characterized jointly by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Rheological tests demonstrated the tunable mechanical strength, formation kinetics, shear thinning and good self-recovery properties of the hydrogels. In addition, the hydrogels can be formed into various shapes by injection. The hydrogel network structure is complex and interlaced, as such it is suitable to encapsulate drugs for controlled release. The drug release from the prepared hydrogels followed the Peppas–Sahlin model and belonged to Fickian diffusion. This study constructed injectable hydrogels through the enzyme-catalyzed cross-linking of modified gelatin and applied the hydrogels for drug release, which is expected to expand the application in biomedical fields.
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Huang, Anshan, Yehong Chen i Chaojun Wu. "Wound Dressing Double-Crosslinked Quick Self-Healing Hydrogel Based on Carboxymethyl Chitosan and Modified Nanocellulose". Polymers 15, nr 16 (13.08.2023): 3389. http://dx.doi.org/10.3390/polym15163389.
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The use of hydrogels in wound dressings, which is pivotal for effective wound treatment, has been widely applied to diverse medical wound conditions. However, formulating natural hydrogels that combine robust strength and self-healing capabilities is a significant challenge. To overcome this, we successfully designed a natural nanocellulose self-healing hydrogel that can quickly self-heal and restore the complete hydrogel structure after injury to fill the injured area and protect the wound from external damage. Our study utilized modified natural polymer carboxymethyl chitosan (CMC), hydrazide-modified carboxymethyl cellulose nanofibers (HCNF), and cellulose nanocrystals modified by dialdehyde (DACNC) to fabricate the hydrogel. The amides containing more amino groups and HCNF in CMC can be used as cross-linking nodes, and the high aspect ratio and specific surface area of DACNC are favorable for the connection of many active hydrogels. The hydrogel is crosslinked by the dynamic imide bond and hydrazone bond between the amino group of CMC, the amide of HCNF, and the aldehyde of DACNC and has a double network structure. These connections can be readily reassembled when disrupted, enabling fast self-healing of hydrogels within five minutes. Moreover, HCNF and DACNC were incorporated as nano-reinforced fillers to bolster the hydrogel’s strength while preserving its high liquid absorption capacity (381% equilibrium swelling rate).
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Han, Xiaoman, Guihua Meng, Qian Wang, Lin Cui, Hao Wang, Jianning Wu, Zhiyong Liu i Xuhong Guo. "Mussel-inspired in situ forming adhesive hydrogels with anti-microbial and hemostatic capacities for wound healing". Journal of Biomaterials Applications 33, nr 7 (22.11.2018): 915–23. http://dx.doi.org/10.1177/0885328218810552.
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All kinds of commercially available wound dressings are clinically used as fleshly obstacles and therapeutic materials in opposition to microbial incursion. Few researches focused on effective-bleeding and anti-bacteria at the same time. In order to better solve this problem, two hydrogels were synthetized in this study. One is phosphate buffer solution-activated dopamine-modified-γ-poly glutamic acid (PBS-PD) hydrogel, the other one is cirsium setosum extracts-activated dopamine-modified-γ-poly glutamic acid (CSE-PD) hydrogel. The two hydrogels are prepared by applying an enzyme-catalyzed crosslinking means in the presence of horseradish peroxidase (HRP) and hydrogen peroxide (H2O2). The chemical structures were characterized through 1H-NMR and FT-IR. In conclusion, both PBS-PD and CSE-PD hydrogels exhibit superior tissue adhesion properties, and remarkable anti-infection quality. In addition, these two hydrogels manifest prominent hemostatic efficiency. The bio adhesion performance can achieve 30 kPa, meanwhile the CSE-PD hydrogels show good germicidal properties, and the antibacterial rate can reach 98%. The hydrogels could reduce blood loss without any obvious side effect, and present a new prospect in the field of hemostasis rapidly.
4
Zhou, Jian, Fu Lu i Zhengwei Wu. "Effects of a plasma jet on electrochemical properties of silk fibroin hydrogel doped with graphene oxide". Polymers and Polymer Composites 30 (styczeń 2022): 096739112211465. http://dx.doi.org/10.1177/09673911221146599.
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This study modified hydrogels prepared from silk fibroinand graphene oxideby injecting plasma into the silk. The SF-GO hydrogels, modified by plasma jet with different discharge time (30, 90, and 150 s) and working gases (argon, air, helium), undergo electrochemical AC impedance spectrum tests. After hydrogel modification with the plasma of any working gas, the impedance in the very low frequency (10−2∼100 Hz) decreased with a longer plasma discharge time. In the very low frequency, the sequence of impedance change is Ar group <air group ≈ He group <empty. The electric capacity of the hydrogel showed an increasing trend with those modified by argon plasma and a decreasing trend for those hydrogels modified by air and helium plasma. The sequence of electric capacity change is Ar group >empty >air group >He group. Fourier transform infrared spectrum, and X-ray diffraction spectrum showed a reduction of β-fold structure and graphene oxide content in SF-GO hydrogels modified by plasma.
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Hejčl, Aleš, Jiří Růžička, Kristýna Kekulová, Barbora Svobodová, Vladimír Proks, Hana Macková, Kateřina Jiránková i in. "Modified Methacrylate Hydrogels Improve Tissue Repair after Spinal Cord Injury". International Journal of Molecular Sciences 19, nr 9 (22.08.2018): 2481. http://dx.doi.org/10.3390/ijms19092481.
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Methacrylate hydrogels have been extensively used as bridging scaffolds in experimental spinal cord injury (SCI) research. As synthetic materials, they can be modified, which leads to improved bridging of the lesion. Fibronectin, a glycoprotein of the extracellular matrix produced by reactive astrocytes after SCI, is known to promote cell adhesion. We implanted 3 methacrylate hydrogels: a scaffold based on hydroxypropylmethacrylamid (HPMA), 2-hydroxyethylmethacrylate (HEMA) and a HEMA hydrogel with an attached fibronectin (HEMA-Fn) in an experimental model of acute SCI in rats. The animals underwent functional evaluation once a week and the spinal cords were histologically assessed 3 months after hydrogel implantation. We found that both the HPMA and the HEMA-Fn hydrogel scaffolds lead to partial sensory improvement compared to control animals and animals treated with plain HEMA scaffold. The HPMA scaffold showed an increased connective tissue infiltration compared to plain HEMA hydrogels. There was a tendency towards connective tissue infiltration and higher blood vessel ingrowth in the HEMA-Fn scaffold. HPMA hydrogels showed a significantly increased axonal ingrowth compared to HEMA-Fn and plain HEMA; while there were some neurofilaments in the peripheral as well as the central region of the HEMA-Fn scaffold, no neurofilaments were found in plain HEMA hydrogels. In conclusion, HPMA hydrogel as well as the HEMA-Fn scaffold showed better bridging qualities compared to the plain HEMA hydrogel, which resulted in very limited partial sensory improvement.
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Dinić, Ana, Vesna Nikolić, Ljubiša Nikolić, Snežana Ilić-Stojanović, Stevo Najman, Maja Urošević i Ivana Gajić. "Modified Sulfanilamide Release from Intelligent Poly(N-isopropylacrylamide) Hydrogels". Pharmaceutics 15, nr 6 (16.06.2023): 1749. http://dx.doi.org/10.3390/pharmaceutics15061749.
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The aim of this study was to examine homopolymeric poly(N-isopropylacrylamide), p(NIPAM), hydrogels cross-linked with ethylene glycol dimethacrylate as carriers for sulfanilamide. Using FTIR, XRD and SEM methods, structural characterization of synthesized hydrogels before and after sulfanilamide incorporation was performed. The residual reactants content was analyzed using the HPLC method. The swelling behavior of p(NIPAM) hydrogels of different crosslinking degrees was monitored in relation to the temperature and pH values of the surrounding medium. The effect of temperature, pH, and crosslinker content on the sulfanilamide release from hydrogels was also examined. The results of the FTIR, XRD, and SEM analysis showed that sulfanilamide is incorporated into the p(NIPAM) hydrogels. The swelling of p(NIPAM) hydrogels depended on the temperature and crosslinker content while pH had no significant effect. The sulfanilamide loading efficiency increased with increasing hydrogel crosslinking degree, ranging from 87.36% to 95.29%. The sulfanilamide release from hydrogels was consistent with the swelling results—the increase of crosslinker content reduced the amount of released sulfanilamide. After 24 h, 73.3–93.5% of incorporated sulfanilamide was released from the hydrogels. Considering the thermosensitivity of hydrogels, volume phase transition temperature close to the physiological temperature, and the satisfactory results achieved for sulfanilamide incorporation and release, it can be concluded that p(NIPAM) based hydrogels are promising carriers for sulfanilamide.
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Zielińska, Aleksandra, Piotr Eder, Lucas Rannier, Juliana C. Cardoso, Patrícia Severino, Amélia M. Silva i Eliana B. Souto. "Hydrogels for Modified-release Drug Delivery Systems". Current Pharmaceutical Design 28, nr 8 (marzec 2022): 609–18. http://dx.doi.org/10.2174/1381612828666211230114755.
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Abstract: Hydrogels for the modified-release drug delivery systems are a continuously growing area of interest for the pharmaceutical industry. According to the global market, the profit resulting from the use of polymers in this area is projected to reach $31.4 million by 2027. This review discusses the recent advances in and perspectives of hydrogel in drug delivery systems for oral, parenteral, nasal, topical, and ophthalmic delivery. The search was conducted, in January 2021, in an extensive database to identify studies published from January 2010 to December 2020. We described the main characteristic of the polymers to obtain an ideal hydrogel for a specific route of administration and the formulations. It was concluded that the hydrogels are useful to decrease the number of doses and side effects, promote adhesion of patient, and enhance the bioavailability of the drugs, thus improving the safety and efficacy of the treatment.
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Sukhanova, T. V., A. A. Artyukhov, I. A. Prudchenko, A. C. Golunova, M. A. Semenikhina, M. I. Shtilman i E. A. Markvicheva. "Delta-sleep inducing peptide entrapment and release from polymer hydrogels based on modified polyvinyl alcohol". Biomeditsinskaya Khimiya 59, nr 1 (styczeń 2013): 65–75. http://dx.doi.org/10.18097/pbmc20135901065.
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The aim of the study was to entrap delta-sleep inducing peptide (DSIP) in cross-linked poly(vinyl alcohol)-based hydrogels of different structures and to evaluate peptide release kinetics from these hydrogels using an in vitro model. Isotropic and macroporous hydrogels on the basis of poly(vinyl alcohol) acrylic derivative (Acr-PVA) as well as macroporous hydogels containing epoxy groups which were synthesized by copolymerization of this monomer with glycidyl methacrylate. The isotropic hydrogels were fabricated at positive temperatures while the macroporous hydrogels (cryogels) were prepared at the temperatures below zero. The peptide was entrapped into macroporous modified PVA hydrogels by addition of a peptide solution on previously fabricated matrices, while into PVA-GMA hydrogels containing epoxy groups peptide immobilization was carried out by incubation of hydrogel matrices in the peptide solution. In the case of isotropic hydrogels the peptide was added into the polymer mixture at a hydrogel formation reaction. The peptide release kinetics was studied by incubation of hydrogels in PBS (pH 7.4), in physiological solution (0.9% NaCl) and in water. DSIP concentration in supernatants was determined by phase-reverse HPLC. DSIP release from the macroporous PVA hydrogel after 30 min incubation was 74, 70 и 64% in water, PBS and 0.9% NaCl, relatively, and it was completed in 3 hs. From the isotropic hydrogel the release neither peptide nor products of its degradation was not observed even after 48 hs of incubation. For freshly prepared hydrogel the release kinetics was as follows: 27 and 78% in 30 and 33 hs, relatively. In the case of the lyophilized hydrogel samples the peptide release was 63% in 30 min incubation while drying patterns at room temperature for 3 days resulted in significant peptide loss because its structure damage.
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Astudillo-Ortiz, Esteban, Pedro S. Babo, Rui L. Reis i Manuela E. Gomes. "Evaluation of Injectable Hyaluronic Acid-Based Hydrogels for Endodontic Tissue Regeneration". Materials 14, nr 23 (30.11.2021): 7325. http://dx.doi.org/10.3390/ma14237325.
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Dental pulp tissue engineering (TE) endeavors to regenerate dentin/pulp complex by combining a suitable supporting matrix, stem cells, and biochemical stimuli. Such procedures foresee a matrix that can be easily introduced into the root canal system (RCS) and tightly adhere to dentin walls to assure the dentin surface’s proper colonization with progenitor cells capable of restoring the dentin/pulp complex. Herein was investigated an injectable self-setting hyaluronic acid-based (HA) hydrogel system, formed by aldehyde-modified (a-HA) with hydrazide-modified (ADH), enriched with platelet lysate (PL), for endodontic regeneration. The hydrogels’ working (wT) and setting (sT) times, the adhesion to the dentine walls, the hydrogel’s microstructure, and the delivery of human dental pulp cells (DPCs) were studied in vitro. Hydrogels incorporating PL showed a suitable wT and sT and a porous microstructure. The tensile tests showed that the breaking point occurs after 4.3106 ± 1.8677 mm deformation, while in the indentation test after 1.4056 ± 0.3065 mm deformation. Both breaking points occur in the hydrogel extension. The HA/PL hydrogels exhibited supportive properties and promoted cell migration toward dentin surfaces in vitro. Overall, these results support using PL-laden HA injectable hydrogels (HA/PL) as a biomaterial for DPCs encapsulation, thereby displaying great clinical potential towards endodontic regenerative therapies.
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Vitale, Mattia, Cosimo Ligorio, Ian P. Smith, Stephen M. Richardson, Judith A. Hoyland i Jordi Bella. "Incorporation of Natural and Recombinant Collagen Proteins within Fmoc-Based Self-Assembling Peptide Hydrogels". Gels 8, nr 5 (21.04.2022): 254. http://dx.doi.org/10.3390/gels8050254.
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Hydrogel biomaterials mimic the natural extracellular matrix through their nanofibrous ultrastructure and composition and provide an appropriate environment for cell–matrix and cell–cell interactions within their polymeric network. Hydrogels can be modified with different proteins, cytokines, or cell-adhesion motifs to control cell behavior and cell differentiation. Collagens are desirable and versatile proteins for hydrogel modification due to their abundance in the vertebrate extracellular matrix and their interactions with cell-surface receptors. Here, we report a quick, inexpensive and effective protocol for incorporation of natural, synthetic and recombinant collagens into Fmoc-based self-assembling peptide hydrogels. The hydrogels are modified through a diffusion protocol in which collagen molecules of different molecular sizes are successfully incorporated and retained over time. Characterization studies show that these collagens interact with the hydrogel fibers without affecting the overall mechanical properties of the composite hydrogels. Furthermore, the collagen molecules incorporated into the hydrogels are still biologically active and provide sites for adhesion and spreading of human fibrosarcoma cells through interaction with the α2β1 integrin. Our protocol can be used to incorporate different types of collagen molecules into peptide-based hydrogels without any prior chemical modification. These modified hydrogels could be used in studies where collagen-based substrates are required to differentiate and control the cell behavior. Our protocol can be easily adapted to the incorporation of other bioactive proteins and peptides into peptide-based hydrogels to modulate their characteristics and their interaction with different cell types.
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Ji, Chongkai, Lijie Li, Yulin Nie, Rang Ping, Jiong Peng i Xin Li. "Polysaccharide-modified conductive hydrogel for flexible electronic devices". Journal of Physics: Conference Series 2563, nr 1 (1.08.2023): 012030. http://dx.doi.org/10.1088/1742-6596/2563/1/012030.
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Abstract In recent years, conductive hydrogels, as an ideal flexible material, have quite broad application prospects in various flexible electronics fields, such as flexible supercapacitors, flexible batteries, and flexible sensors. However, mechanical stress such as stretching, fracture, and compression will affect the performance of conductive hydrogel during the application, which limits its further application. Polysaccharides, such as cellulose and chitosan, are widely distributed and easy-to-obtain biological macromolecules, which contain a large number of polar functional groups (carboxyl, amino, etc.), which can be formed with polymer hydrogel molecular chains, thereby improving the performance of the hydrogel. Herein, we prepared a kind of conductive hydrogel with high toughness, high conductivity, and self-adhesion by introducing carboxymethyl chitosan and maltose to induce a dynamic Schiff base reaction in the hydrogel. It is conceived that this study proposed a potential approach for the progress of conductive hydrogels in various flexible electronics fields.
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Zhang, Junyu, i Zhao Wang. "Nanoparticle–Hydrogel Based Sensors: Synthesis and Applications". Catalysts 12, nr 10 (22.09.2022): 1096. http://dx.doi.org/10.3390/catal12101096.
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Hydrogels are hydrophilic three-dimensional (3D) porous polymer networks that can easily stabilize various nanoparticles. Loading noble metal nanoparticles into a 3D network of hydrogels can enhance the synergy of the components. It can also be modified to prepare intelligent materials that can recognize external stimuli. The combination of noble metal nanoparticles and hydrogels to produce modified or new composite materials has attracted considerable attention as to the use of these materials in sensors. However, there is limited review literature on nanoparticle–hydrogel-based sensors. This paper presents the detailed strategies of synthesis and design of the composites, and the latest applications of nanoparticle–hydrogel materials in the sensing field. Finally, the current challenges and future development directions of nanoparticle–hydrogel-based sensors are proposed.
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Racksanti, Anucha, Sorapong Janhom, Sittiporn Punyanitya, Ruangsri Watanesk i Surasak Watanesk. "Crosslinking Density of Silk Fibroin – Rice Starch Hydrogels Modified with Trisodium Trimetaphosphate". Applied Mechanics and Materials 446-447 (listopad 2013): 366–72. http://dx.doi.org/10.4028/www.scientific.net/amm.446-447.366.
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Silk fibroin (SF) and rice starch (RS) are both biopolymers being non-toxic, biocompatible and biodegradable which can be utilized as hydrogels. The aim of this study was to prepare the SF–RS hydrogels modified with trisodium trimetaphosphate (STMP) and determine its crosslinking density for providing a guideline for preparing better quality absorbable hydrogels. The SF–RS hydrogels modified with various percentages of STMP were prepared by solution casting at pH 12 then neutralized to pH 7. The functional groups and molecular linkages of the hydrogels were investigated by Fourier transform infrared spectrometry (FTIR) and proton nuclear magnetic resonance (1H NMR) spectrometry, respectively. Finally, the crosslinking density of the hydrogels was determined by UV/Vis spectrophotometry via the measurement of the relative amount of methylene blue (RMB) bound to the hydrogels. Results from the FTIR and 1H NMR spectra revealed that linkages within the hydrogels occurred mainly between the O–H groups of RS and the triphosphate groups of STMP. From the MB adsorption study, the crosslinking density of the SF–RS hydrogel with 1.0 %w/w STMP at the 60 min saturation time was approximately 63 %.
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Zhou, Ying Xue, Xiao Dong Fan i Dan Xue. "Polypseudorotaxane Hydrogels Based on F127 Block-Selected Inclusion Complexation with α-Cyclodextrin". Advanced Materials Research 482-484 (luty 2012): 1898–903. http://dx.doi.org/10.4028/www.scientific.net/amr.482-484.1898.
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Supramolecular hydrogels were formed through F127, acryloyl chloride modified F127 inclusion complex with α-cyclodextrin, respectively. The structure of modified copolymers and inclusion complex was characterized by Fourier transform infrared spectroscopy (FTIR) and hydrogen nuclear magnetic resonance (1H-NMR). Hydrogels formed from supramolecular inclusion are imparted channel-type structure investigated by wide angle x-ray diffraction (WAXRD). Differential scanning calorimetry (DSC) and TG experiments showed that thermal stability of hydrogels depend on the nature of axis polymer. The relative model was proposed to elucidate the inclusion complexes and hydrogels formation.
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Bańkosz, Magdalena. "Development of Chitosan/Gelatin-Based Hydrogels Incorporated with Albumin Particles". International Journal of Molecular Sciences 23, nr 22 (16.11.2022): 14136. http://dx.doi.org/10.3390/ijms232214136.
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The research subject of this paper are natural polymer-based hydrogels modified with albumin particles. The proteins were obtained via the salt-induced precipitation method, and next characterized using dynamic light scattering (DLS), UV-Vis spectroscopy and FT-IR spectroscopy. The most favorable composition showing monodispersity and particles with a size lower than 40 nm was selected for modification of hydrogels. Such systems were obtained via the photopolymerization performed under the influence of UV radiation using diacrylate poly(ethylene glycol) as a crosslinking agent and 2-hydroxy-2-methylpropiophenone as a photoinitiator. Next, the hydrogels’ swelling ability, mechanical properties, wettability and surface morphology were characterized. Moreover, FT-IR spectroscopy, incubation studies in simulated physiological liquids, pro-inflammatory activity analysis and MTT reduction assay with L929 murine fibroblasts were performed. The release profiles of proteins from hydrogels were also verified. Materials modified with proteins showed higher swelling ability, increased flexibility even by 50% and increased surface hydrophilicity. Hydrogels’ contact angles were within the range 62–69° while the tensile strength of albumin-containing hydrogels was approx. 0.11 MPa. Furthermore, the possibility of the effective release of protein particles from hydrogels in acidic environment (approximately 70%) was determined. Incubation studies showed hydrogels’ stability and lack of their degradation in tested media. The viability of fibroblasts was 89.54% for unmodified hydrogel, and approx. 92.73% for albumin-modified hydrogel, and such an increase indicated the positive impact of the albumin on murine fibroblast proliferation.
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Fu, Li, Aimin Yu i Guosong Lai. "Conductive Hydrogel-Based Electrochemical Sensor: A Soft Platform for Capturing Analyte". Chemosensors 9, nr 10 (4.10.2021): 282. http://dx.doi.org/10.3390/chemosensors9100282.
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Electrode modifications for electrochemical sensors attract a lot of attention every year. Among them, hydrogels are a relatively special class of electrode modifier. Since hydrogels often contain polymers, even though they are conductive polymers, they are not ideal electrode modifiers because of their poor conductivity. However, the micro-aqueous environment and the three-dimensional structure of hydrogels are an excellent platform for immobilizing bioactive molecules and maintaining their activity. This gives the hydrogel-modified electrochemical sensor the potential to perform specific recognition. At the same time, the rapid development of nanomaterials also makes the composite hydrogel have good electrical conductivity. This has led many scientists to become interested in hydrogel-based electrochemical sensors. In this review, we summarize the development process of hydrogel-based electrochemical sensors, starting from 2000. Hydrogel-based electrochemical sensors were initially used only as a carrier for biomolecules, mostly for loading enzymes and for specific recognition. With the widespread use of noble metal nanoparticles and carbon materials, hydrogels can now be used to prepare enzyme-free sensors. Although there are some sporadic studies on the use of hydrogels for practical applications, the vast majority of reports are still limited to the detection of common model molecules, such as glucose and H2O2. In the review, we classify hydrogels according to their different conducting strategies, and present the current status of the application of different hydrogels in electrochemical sensors. We also summarize the advantages and shortcomings of hydrogel-based electrochemical sensors. In addition, future prospects regarding hydrogel for electrochemical sensor use have been provided at the end.
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Akhramez, Soufiane, Ahmed Fatimi, Oseweuba Valentine Okoro, Maryam Hajiabbas, Abdelghani Boussetta, Amine Moubarik, Abderrafia Hafid i in. "The Circular Economy Paradigm: Modification of Bagasse-Derived Lignin as a Precursor to Sustainable Hydrogel Production". Sustainability 14, nr 14 (18.07.2022): 8791. http://dx.doi.org/10.3390/su14148791.
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There have been many efforts to valorise lignin to produce bio-based chemicals and advanced materials. In this study, alkaline delignification was initially employed to recover lignin from the rind, pulp, and whole bagasse fractions of Moroccan sugarcane. The lignin fractions were subsequently modified via silanization and acetylation reactions. The modified lignin and raw lignin were then characterised to assess changes in their physicochemical properties via Fourier transform infrared spectroscopy (FTIR), solubility and thermogravimetric assessment, with both salinization and acetylation modification shown to enhance the solubility properties of the raw lignin of both polar and non-polar solvents. Preliminary investigations into the suitability of employing the modified lignin in hydrogel preparation were also undertaken. The preliminary hydrogels were developed using heating and freeze-thawing methods, while polyvinyl alcohol (PVA) and epichlorohydrin (ECH) were used as the matrix and the crosslinking agents, respectively. Fourier transform infrared spectroscopy (FTIR), rheological analysis, scanning electron microscopy, and thermal analysis were then used to characterize the different lignin–PVA hydrogels. The study showed that the swelling behaviour of the hydrogels was mainly influenced by the nature of the lignin (i.e., modified or raw), and the morphology of the hydrogel surfaces varied depending on the preparation methods. The study showed that the hydrogel based on silanized lignin and PVA had superior mechanical performance and swelling capacity compared to the acetylated lignin–PVA and raw lignin–PVA hydrogels.
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Fukuhara, Yoshiki, Yshihiro Ohzuno, Takayuki Takei i Masahiro Yoshida. "Effect of Alkyl Chain Length on Adsorption and Release of Hydrophobic Drug to/from Hydrophobically-modified Gelatin Hydrogel". MATEC Web of Conferences 333 (2021): 11008. http://dx.doi.org/10.1051/matecconf/202133311008.
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Hydrogels have become popular as drug carriers. Controlled release of the drugs from hydrogels can reduce dosage, inducing prevention of side effects. However, the hydrophilicity of hydrogels interferes with controlled release of hydrophobic drugs such as anticancer agents or antibiotics. In this study, we developed hydrophobically-modified gelatin (HMG) hydrogel, which was cross-linked only by hydrophobic interaction. HMG does not require toxic chemical cross-linkers to form hydrogel. In addition, the HMG hydrogel has hydrophobic chambers in its structure which hydrophobic drugs can adsorb to and desorb from. In order to control the amount of hydrophobic drugs adsorbed into the hydrogel, hydrophobic alkyl chains with different lengths (C4-C12) were incorporated into gelatin molecules. Uranine was used as a model for hydrophobic drugs. The adsorption test exhibited that the amount of uranine adsorbed in HMG hydrogels could be controlled by varying hydrophobic alkyl chain length and that the drug could be released in a controlled manner. These results show that HMG hydrogels are promising carriers of hydrophobic drugs.
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Fukuhara, Yoshiki, Yshihiro Ohzuno, Takayuki Takei i Masahiro Yoshida. "Effect of Alkyl Chain Length on Adsorption and Release of Hydrophobic Drug to/from Hydrophobically-modified Gelatin Hydrogel". MATEC Web of Conferences 333 (2021): 11008. http://dx.doi.org/10.1051/matecconf/202133311008.
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Hydrogels have become popular as drug carriers. Controlled release of the drugs from hydrogels can reduce dosage, inducing prevention of side effects. However, the hydrophilicity of hydrogels interferes with controlled release of hydrophobic drugs such as anticancer agents or antibiotics. In this study, we developed hydrophobically-modified gelatin (HMG) hydrogel, which was cross-linked only by hydrophobic interaction. HMG does not require toxic chemical cross-linkers to form hydrogel. In addition, the HMG hydrogel has hydrophobic chambers in its structure which hydrophobic drugs can adsorb to and desorb from. In order to control the amount of hydrophobic drugs adsorbed into the hydrogel, hydrophobic alkyl chains with different lengths (C4-C12) were incorporated into gelatin molecules. Uranine was used as a model for hydrophobic drugs. The adsorption test exhibited that the amount of uranine adsorbed in HMG hydrogels could be controlled by varying hydrophobic alkyl chain length and that the drug could be released in a controlled manner. These results show that HMG hydrogels are promising carriers of hydrophobic drugs.
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Du, Bin, Yi Chao, Kenan Yang, Bin Li, Rubai Luo, Shisheng Zhou i Huailin Li. "Stretchable and tough tannic acid-modified graphene oxide/ polyvinyl alcohol conductive hydrogels for strain and pressure sensors". AIP Advances 12, nr 9 (1.09.2022): 095206. http://dx.doi.org/10.1063/5.0098621.
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With the rise of new fields such as wearable devices, human health monitoring, and artificial intelligence, flexible sensors have received extensive attention. Conductive hydrogels combine conductive fillers with the excellent properties of hydrogels, making them ideal materials for building flexible sensors. However, conductive hydrogels suffer from poor mechanical properties and low sensitivity, and designing hydrogels with high electrical conductivity and excellent mechanical properties remains a challenge. In this work, a conductive TA-RGO/PVA hydrogel was developed by incorporating TA-RGO nanocomposites into a PVA matrix. The prepared TA-RGO/PVA hydrogel exhibited excellent electrical conductivity, good elastic strain, and excellent mechanical stress. TA-RGO/PVA hydrogels can be used for stretchable strain and pressure sensors. The strain sensor based on the TA-RGO/PVA hydrogel exhibits excellent tensile strain sensitivity (1.936 78 gage factor in the 1%–280% strain region) with excellent stability. The sensor also maintains high sensitivity when used as a pressure sensor (2.2695 kPa−1 in the 0–9 kPa pressure range). These characteristics offer the TA-RGO/PVA hydrogel great potential in the application of wearable flexible strain/pressure sensors and bioelectrodes.
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Kozicki, Marek, Aleksandra Pawlaczyk, Aleksandra Adamska, Małgorzata Iwona Szynkowska-Jóźwik i Elżbieta Sąsiadek-Andrzejczak. "Golden and Silver–Golden Chitosan Hydrogels and Fabrics Modified with Golden Chitosan Hydrogels". International Journal of Molecular Sciences 23, nr 10 (12.05.2022): 5406. http://dx.doi.org/10.3390/ijms23105406.
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Golden and silver–golden chitosan hydrogels and hydrogel-modified textiles of potential biomedical applications are investigated in this work. The hydrogels are formed by reactions of chitosan with HAuCl4·xH2O. For above the critical concentration of chitosan (c*), chitosan–Au hydrogels were prepared. For chitosan concentrations lower than c*, chitosan–Au nano- and microgels were formed. To characterise chitosan–Au structures, sol–gel analysis, UV–Vis spectrophotometry and dynamic light scattering were performed. Au concentration in the hydrogels was determined by the flame atomic absorption spectrophotometry. Colloidal chitosan–Au solutions were used for the modification of fabrics. The Au content in the modified fabrics was quantified by inductively coupled plasma mass spectrometry technique. Scanning electron microscopy with energy dispersion X-ray spectrometer was used to analyse the samples. Reflectance spectrophotometry was applied to examine the colour of the fabrics. The formation of chitosan–Au–Ag hydrogels by the competitive reaction of Au and Ag ions with the chitosan macromolecules is reported.
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Siahaan, Tanty N., Basuki Basuki, Amir H. Siregar i Dede I. Muthawali. "Morphological Effect on Swelling Behaviour of Carboxymethyl Cellulose–Maleic Acid Hydrogel Modified with Kombucha Bacterial Cellulose". Jurnal Akademika Kimia 12, nr 2 (30.05.2023): 86–91. http://dx.doi.org/10.22487/j24775185.2023.v12.i2.pp86-91.
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The incorporation of bacterial cellulose from kombucha tea in carboxymethyl cellulose / maleic acid (CMC / MA) hydrogels has been successfully conducted. This study aims to analyze the relationship between the pores on the surface of the hydrogel with their water-absorbing ability. Bacterial cellulose from kombucha (KBC) was confirmed by the spectrum of OH, C-O-C, and C-OH functional groups with FT - IR analysis. Filler KBC was added to CMC / MA hydrogel with variations in the concentration of 2, 4, 6, and 8 % wt. The CMC / MA / KBC hydrogels were characterized by swelling test, degree of crosslinking, FTIR, and SEM. The swelling results showed that hydrogels with 2 % KBC produced the best water absorbing ability up to 172 %, water absorption decreased with the increase of KBC concentrations. Furthermore, SEM image results showed that the addition of KBC affects the morphological shape and pore size of the hydrogel. Meanwhile, FTIR analysis showed that there were no major changes in the functional groups of hydrogels.
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Li, Gangrong, Qianhui Wei, Shuhua Wei, Jing Zhang, Qingxi Jin, Guozhi Wang, Jiawei Hu i in. "Acrylamide Hydrogel-Modified Silicon Nanowire Field-Effect Transistors for pH Sensing". Nanomaterials 12, nr 12 (16.06.2022): 2070. http://dx.doi.org/10.3390/nano12122070.
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In this study, we report a pH-responsive hydrogel-modified silicon nanowire field-effect transistor for pH sensing, whose modification is operated by spin coating, and whose performance is characterized by the electrical curve of field-effect transistors. The results show that the hydrogel sensor can measure buffer pH in a repeatable and stable manner in the pH range of 3–13, with a high pH sensitivity of 100 mV/pH. It is considered that the swelling of hydrogel occurring in an aqueous solution varies the dielectric properties of acrylamide hydrogels, causing the abrupt increase in the source-drain current. It is believed that the design of the sensor can provide a promising direction for future biosensing applications utilizing the excellent biocompatibility of hydrogels.
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Michalicha, Anna, Agata Przekora, Dawid Stefaniuk, Magdalena Jaszek, Anna Matuszewska i Anna Belcarz. "Medical Use of Polycatecholamines + Oxidoreductases-Modified Curdlan Hydrogels—Perspectives". International Journal of Molecular Sciences 23, nr 17 (3.09.2022): 10084. http://dx.doi.org/10.3390/ijms231710084.
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Curdlan (β-1,3-glucan), as a biodegradable polymer, is still an underestimated but potentially attractive matrix for the production of dressing materials. However, due to its lack of susceptibility to functionalization, its use is limited. The proposed curdlan modification, using a functional polycatecholamine layer, enables the immobilization of selected oxidoreductases (laccase and peroxidase) on curdlan hydrogel. The following significant changes of biological and mechanical properties of polycatecholamines + oxidoreductases-modified matrices were observed: reduced response of human monocytes in contact with the hydrogels, modulated reaction of human blood, in terms of hemolysis and clot formation, and changed mechanical properties. The lack of toxicity towards human fibroblasts and the suppression of cytokines released by human monocytes in comparison to pristine curdlan hydrogel, seems to make the application of such modifications attractive for biomedical purposes. The obtained results could also be useful for construction of a wide range of biomaterials based on other polymer hydrogels.
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Li, Rongkai, Qinbing Qi, Chunhua Wang, Guige Hou i Chengbo Li. "Self-Healing Hydrogels Fabricated by Introducing Antibacterial Long-Chain Alkyl Quaternary Ammonium Salt into Marine-Derived Polysaccharides for Wound Healing". Polymers 15, nr 6 (15.03.2023): 1467. http://dx.doi.org/10.3390/polym15061467.
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The development of hydrogels as wound dressings has gained considerable attention due to their promising ability to promote wound healing. However, in many cases of clinical relevance, repeated bacterial infection, which might obstruct wound healing, usually occurs due to the lack of antibacterial properties of these hydrogels. In this study, we fabricated a new class of self-healing hydrogel with enhanced antibacterial properties based on dodecyl quaternary ammonium salt (Q12)-modified carboxymethyl chitosan (Q12-CMC), aldehyde group- modified sodium alginate (ASA), Fe3+ via Schiff bases and coordination bonds (QAF hydrogels). The dynamic Schiff bases and coordination interactions conferred excellent self-healing abilities to the hydrogels, while the incorporation of dodecyl quaternary ammonium salt gave the hydrogels superior antibacterial properties. Additionally, the hydrogels displayed ideal hemocompatibility and cytocompatibility, crucial for wound healing. Our full-thickness skin wound studies demonstrated that QAF hydrogels could result in rapid wound healing with reduced inflammatory response, increased collagen disposition and improved vascularization. We anticipate that the proposed hydrogels, possessing both antibacterial and self-healing properties, will emerge as a highly desirable material for skin wound repair.
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Gadziński, Piotr, Anna Froelich, Barbara Jadach, Monika Wojtyłko, Adam Tatarek, Antoni Białek, Julia Krysztofiak, Michał Gackowski, Filip Otto i Tomasz Osmałek. "Ionotropic Gelation and Chemical Crosslinking as Methods for Fabrication of Modified-Release Gellan Gum-Based Drug Delivery Systems". Pharmaceutics 15, nr 1 (28.12.2022): 108. http://dx.doi.org/10.3390/pharmaceutics15010108.
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Hydrogels have a tridimensional structure. They have the ability to absorb a significant amount of water or other natural or simulated fluids that cause their swelling albeit without losing their structure. Their properties can be exploited for encapsulation and modified targeted drug release. Among the numerous natural polymers suitable for obtaining hydrogels, gellan gum is one gaining much interest. It is a gelling agent with many unique features, and furthermore, it is non-toxic, biocompatible, and biodegradable. Its ability to react with oppositely charged molecules results in the forming of structured physical materials (films, beads, hydrogels, nanoparticles). The properties of obtained hydrogels can be modified by chemical crosslinking, which improves the three-dimensional structure of the gellan hydrogel. In the current review, an overview of gellan gum hydrogels and their properties will be presented as well as the mechanisms of ionotropic gelation or chemical crosslinking. Methods of producing gellan hydrogels and their possible applications related to improved release, bioavailability, and therapeutic activity were described.
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Ilic-Stojanovic, Snezana, Ljubisa Nikolic, Vesna Nikolic, Jela Milic, Jakov Stamenkovic, Goran Nikolic i Slobodan Petrovic. "Synthesis and characterization of thermosensitive hydrogels and the investigation of modified release of ibuprofen". Chemical Industry 67, nr 6 (2013): 901–12. http://dx.doi.org/10.2298/hemind130119038i.
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The method of the synthesis of poly(N-isopropylacrylamide-co-2-hydroxypropyl methacrylate) hydrogels obtained by radical polymerization is described. Their characterization was carried out by the determination of the quantity of residual monomers and by investigating their structure using the FTIR. Three glass transitions were detected by DSC method. The porous surfaces of hydrogels with incorporated ibuprofen were shown in SEM micrographs. The swelling ratio of hydrogels decreased with the temperature increase and the swelling transport mechanism was changed from non-Fickian to Fickian. Ibuprofen was incorporated in hydrogel as a drug carrier and released quantity was monitored by HPLC method depending on the temperature. Hydrogel with the lower cross-linker content had the highest swelling degree (? = 34.72) at 10?C and released the largest amount of ibuprofen (64.21 mg/gxerogel) at 40?C.
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Głąb, Magdalena, Anna Drabczyk, Sonia Kudłacik-Kramarczyk, Marcel Krzan i Bożena Tyliszczak. "Physicochemical Characteristics of Chitosan-Based Hydrogels Modified with Equisetum arvense L. (Horsetail) Extract in View of Their Usefulness as Innovative Dressing Materials". Materials 14, nr 24 (8.12.2021): 7533. http://dx.doi.org/10.3390/ma14247533.
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This work focused on obtaining and characterizing hydrogels with their potential application as dressing materials for chronic wounds. The research included synthesizing chitosan-based hydrogels modified with Equisetum arvense L. (horsetail) extract via photopolymerization, and their characteristics determined with regard to the impact of both the modifier and the amount of crosslinker on their properties. The investigations included determining their sorption properties and tensile strength, evaluating their behavior in simulated physiological liquids, and characterizing their wettability and surface morphology. The release profile of horsetail extract from polymer matrices in acidic and alkaline environments was also verified. It was proved that hydrogels showed swelling ability while the modified hydrogels swelled slightly more. Hydrogels showed hydrophilic nature (all contact angles were <77°). Materials containing horsetail extract exhibited bigger elasticity than unmodified polymers (even by 30%). It was proved that the extract release was twice as effective in an acidic medium. Due to the possibility of preparation of hydrogels with specific mechanical properties (depending on both the modifier and the amount of crosslinker used), wound exudate sorption ability, and possibility of the release of active substance, hydrogels show a great application potential as dressing materials.
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Michalicha, Anna, Anna Tomaszewska, Vladyslav Vivcharenko, Barbara Budzyńska, Magdalena Kulpa-Greszta, Dominika Fila, Robert Pązik i Anna Belcarz. "Poly(levodopa)-Functionalized Polysaccharide Hydrogel Enriched in Fe3O4 Particles for Multiple-Purpose Biomedical Applications". International Journal of Molecular Sciences 24, nr 9 (28.04.2023): 8002. http://dx.doi.org/10.3390/ijms24098002.
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In recent years, there has been a significant increase in interest in the use of curdlan, a naturally derived polymer, for medical applications. However, it is relatively inactive, and additives increasing its biomedical potential are required; for example, antibacterial compounds, magnetic particles, or hemostatic agents. The stability of such complex constructs may be increased by additional functional networks, for instance, polycatecholamines. The article presents the production and characterization of functional hydrogels based on curdlan enriched with Fe3O4 nanoparticles (NPs) or Fe3O4–based heterostructures and poly(L-DOPA) (PLD). Some of the prepared modified hydrogels were nontoxic, relatively hemocompatible, and showed high antibacterial potential and the ability to convert energy with heat generation. Therefore, the proposed hydrogels may have potential applications in temperature-controlled regenerative processes as well as in oncology therapies as a matrix of increased functionality for multiple medical purposes. The presence of PLD in the curdlan hydrogel network reduced the release of the NPs but slightly increased the hydrogel’s hemolytic properties. This should be taken into account during the selection of the final hydrogel application.
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Budianto, Emil, i Annissa Amalia. "Swelling behavior and mechanical properties of Chitosan-Poly(N-vinyl-pyrrolidone) hydrogels". Journal of Polymer Engineering 40, nr 7 (27.08.2020): 551–60. http://dx.doi.org/10.1515/polyeng-2019-0169.
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AbstractIn this research, three modified chitosan-based hydrogels are synthesized, i.e., a crosslinked chitosan hydrogel and semi- and fully-interpenetrating polymer network (IPN) chitosan hydrogels fabricated using poly(N-vinyl-pyrrolidone). A non-modified chitosan hydrogel was also synthesized as a control. These samples were compared regarding their swelling behavior and mechanical properties. The hydrogels were characterized by Fourier Transform Infrared (FTIR) analysis and microscopy observations. The effect of crosslinking on the swelling capacity and on the swelling kinetics were evaluated in distilled water, simulated gastric fluid (SGF), and simulated intestinal fluid (SIF) at 37 °C, and the data were interpreted using various kinetic models. Finally, the mechanical properties were evaluated based on the tensile strength using a universal tensile testing machine. The results revealed that the swelling process conformed to the Schott model (pseudo-second-order kinetics), with Fickian diffusion as the diffusion mechanism type. The hydrogels all showed similar trends in their swelling kinetics. However, the full-IPN hydrogel exhibited the lowest equilibrium swelling capacity and the highest swelling rate. The mechanical test results indicate that the crosslinking model affects the resulting tensile strength.
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Kocak, Fatma Z., Muhammad Yar i Ihtesham U. Rehman. "Hydroxyapatite-Integrated, Heparin- and Glycerol-Functionalized Chitosan-Based Injectable Hydrogels with Improved Mechanical and Proangiogenic Performance". International Journal of Molecular Sciences 23, nr 10 (11.05.2022): 5370. http://dx.doi.org/10.3390/ijms23105370.
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The investigation of natural bioactive injectable composites to induce angiogenesis during bone regeneration has been a part of recent minimally invasive regenerative medicine strategies. Our previous study involved the development of in situ-forming injectable composite hydrogels (Chitosan/Hydroxyapatite/Heparin) for bone regeneration. These hydrogels offered facile rheology, injectability, and gelation at 37 °C, as well as promising pro-angiogenic abilities. In the current study, these hydrogels were modified using glycerol as an additive and a pre-sterile production strategy to enhance their mechanical strength. These modifications allowed a further pH increment during neutralisation with maintained solution homogeneity. The synergetic effect of the pH increment and further hydrogen bonding due to the added glycerol improved the strength of the hydrogels substantially. SEM analyses showed highly cross-linked hydrogels (from high-pH solutions) with a hierarchical interlocking pore morphology. Hydrogel solutions showed more elastic flow properties and incipient gelation times decreased to just 2 to 3 min at 37 °C. Toluidine blue assay and SEM analyses showed that heparin formed a coating at the top layer of the hydrogels which contributed anionic bioactive surface features. The chick chorioallantoic membrane (CAM) assay confirmed significant enhancement of angiogenesis with chitosan-matrixed hydrogels comprising hydroxyapatite and small quantities of heparin (33 µg/mL) compared to basic chitosan hydrogels.
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Głąb, Magdalena, Anna Drabczyk, Sonia Kudłacik-Kramarczyk, Martin Duarte Guigou, Agnieszka Makara, Paweł Gajda, Josef Jampilek i Bożena Tyliszczak. "Starch Solutions Prepared under Different Conditions as Modifiers of Chitosan/Poly(aspartic acid)-Based Hydrogels". Materials 14, nr 16 (8.08.2021): 4443. http://dx.doi.org/10.3390/ma14164443.
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Recently, there has been great interest in the application of polysaccharides in the preparation of diverse biomaterials which result from their biocompatibility, biodegradability and biological activity. In this work, the investigations on chitosan/poly(aspartic acid)-based hydrogels modified with starch were described. Firstly, a series of hydrogel matrices was prepared and investigated to characterize their swelling properties, structure via FT-IR spectroscopy, elasticity and tensile strength using the Brookfield texture analyzer as well as their impact on simulated physiological liquids. Hydrogels consisting of chitosan and poly(aspartic acid) in a 2:1 volume ratio were elastic (9% elongation), did not degrade after 30-day incubation in simulated physiological liquids, exhibited a relative biocompatibility towards these liquids and similar swelling in each absorbed medium. This hydrogel matrix was modified with starch wherein two of its form were applied—a solution obtained at an elevated temperature and a suspension obtained at room temperature. Hydrogels modified with hot starch solution showed higher sorption that unmodified materials. This was probably due to the higher starch inclusion (i.e., a larger number of hydrophilic groups able to interact with the adsorbed liquid) when this polysaccharide was given in the form of a hot solution. Hydrogels modified with a cold starch suspension had visible heterogeneous inequalities on their surfaces and this modification led to the obtainment materials with unrepeatable structures which made the analysis of their properties difficult and may have led to misleading conclusions.
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Okay, Oguz. "Re-Entrant Conformation Transition in Hydrogels". Gels 7, nr 3 (20.07.2021): 98. http://dx.doi.org/10.3390/gels7030098.
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Hydrogels are attractive materials not only for their tremendous applications but also for theoretical studies as they provide macroscopic monitoring of the conformation change of polymer chains. The pioneering theoretical work of Dusek predicting the discontinuous volume phase transition in gels followed by the experimental observation of Tanaka opened up a new area, called smart hydrogels, in the gel science. Many ionic hydrogels exhibit a discontinuous volume phase transition due to the change of the polymer–solvent interaction parameter χ depending on the external stimuli such as temperature, pH, composition of the solvent, etc. The observation of a discontinuous volume phase transition in nonionic hydrogels or organogels is still a challenging task as it requires a polymer–solvent system with a strong polymer concentration dependent χ parameter. Such an observation may open up the use of organogels as smart and hydrophobic soft materials. The re-entrant phenomenon first observed by Tanaka is another characteristic of stimuli responsive hydrogels in which they are frustrated between the swollen and collapsed states in a given solvent mixture. Thus, the hydrogel first collapses and then reswells if an environmental parameter is continuously increased. The re-entrant phenomenon of hydrogels in water–cosolvent mixtures is due to the competitive hydrogen-bonding and hydrophobic interactions leading to flow-in and flow-out of the cosolvent molecules through the hydrogel moving boundary as the composition of the solvent mixture is varied. The experimental results reviewed here show that a re-entrant conformation transition in hydrogels requires a hydrophobically modified hydrophilic network, and a moderate hydrogen-bonding cosolvent having competitive attractions with water and polymer. The re-entrant phenomenon may widen the applications of the hydrogels in mechanochemical transducers, switches, memories, and sensors.
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Mikušová, Veronika, Jarmila Ferková, Dominika Žigrayová, Daniel Krchňák i Peter Mikuš. "Comparative Study of Polysaccharide-Based Hydrogels: Rheological and Texture Properties and Ibuprofen Release". Gels 8, nr 3 (7.03.2022): 168. http://dx.doi.org/10.3390/gels8030168.
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Polysaccharides are attractive gelling agents in pharmacy due to their safety, biocompatibility, biodegradability, relatively easy way of preparation, and low price. Due to their variable physical-chemical properties, polysaccharides have potentialities to be used for designing new drug delivery systems for controlled drug release. In this comparative study, rheological and texture properties as well as the in vitro release of model drug ibuprofen (IBU) with 11 polysaccharide-based hydrogels were investigated. The in vitro release of IBU significantly differed between (i) neutral (hydroxy/alkylcelluloses), (ii) anionic (carboxyalkylcellulose and its sodium salt, tragacanth, carrageenan, xanthan gum), and (iii) cationic (chitosans) hydrogels due to different contribution of provided interactions and viscosity within the hydrogel groups. The drug release kinetics of each hydrogel system was evaluated for five kinetic models. Several combinations of cationic hydrogels with neutral or anionic ones were performed to illustrate possibilities of providing modified IBU release profiles. In this context, chitosan was presented as an effective modifier of diffusion profiles for negatively charged drugs formulated into combined polymeric systems, providing their prolonged release. The most appropriate hydrogel for the topical application (i.e., providing favorable rheological and texture properties along with the highest drug release) was selected from a studied series of polysaccharide-based hydrogels.
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Kudłacik-Kramarczyk, Sonia, Anna Drabczyk, Magdalena Głąb, Paweł Gajda, Anna Jaromin, Anna Czopek, Agnieszka Zagórska i Bożena Tyliszczak. "Synthesis and Physicochemical Evaluation of Bees’ Chitosan-Based Hydrogels Modified with Yellow Tea Extract". Materials 14, nr 12 (18.06.2021): 3379. http://dx.doi.org/10.3390/ma14123379.
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The novelty of the research involves designing the measurement methodology aimed at determining the structure–property relationships in the chitosan-based hydrogels containing yellow tea extract. Performed investigations allowed us to determine the swelling properties of hydrogels in selected time intervals, evaluate the mutual interactions between the hydrogels and simulated physiological liquids via pH measurements and directly assess the impact of such interactions on the chemical structure of hydrogels using Fourier transform infrared (FT-IR) spectroscopy and their wettability by the measurements of the flatness of the drop on the surface of the tested samples via the static drop method. Next, the surface morphology of hydrogels was characterized by the Scanning Electron Miscorcopy (SEM) and their elasticity under the tension applied was also verified. It was proved that incubation in simulated physiological liquids resulted in a decrease in contact angles of hydrogels, even by 60%. This also caused their certain degradation which was reflected in lower intensities of bands on FT-IR spectra. Further, 23% v/v yellow tea extract in hydrogel matrices caused the decrease of their tensile strength. An increase in the amount of the crosslinker resulted in a decrease in the sorption capacity of hydrogels wherein their modification caused greater swelling ability. In general, the investigations performed provided much information on the tested materials which may be meaningful considering their application, e.g., as dressing materials.
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Prabahar, Joshua, Babak Vafaei i Ali Ghahremaninezhad. "The Effect of Hydrogels with Different Chemical Compositions on the Behavior of Alkali-Activated Slag Pastes". Gels 8, nr 11 (10.11.2022): 731. http://dx.doi.org/10.3390/gels8110731.
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The effect of in-house synthesized hydrogels with different chemical compositions on the properties of alkali-activated slag pastes was examined. It was found that the teabag test and modified teabag test as a direct method and the flow test as an indirect method showed a similar trend in hydrogel absorption; however, the absorption values differ noticeably between the direct and indirect methods. The alkali-activated slag pastes with hydrogels demonstrated a significant reduction in autogenous shrinkage compared to the pastes without hydrogels. The creation of macrovoids by the hydrogels and change in pore structure resulted in a decrease in compressive strength and electrical resistivity of the pastes with hydrogels. The absorption and desorption of hydrogels in the pastes were tracked using X-ray microcomputed tomography (micro-CT), and it was shown that the onset of hydrogel desorption approximately coincided with the final setting time of the pastes.
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Juriga, David, Eszter Eva Kalman, Krisztina Toth, Dora Barczikai, David Szöllősi, Anna Földes, Gabor Varga, Miklos Zrinyi, Angela Jedlovszky-Hajdu i Krisztina S. Nagy. "Analysis of Three-Dimensional Cell Migration in Dopamine-Modified Poly(aspartic acid)-Based Hydrogels". Gels 8, nr 2 (18.01.2022): 65. http://dx.doi.org/10.3390/gels8020065.
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Several types of promising cell-based therapies for tissue regeneration have been developing worldwide. However, for successful therapeutical application of cells in this field, appropriate scaffolds are also required. Recently, the research for suitable scaffolds has been focusing on polymer hydrogels due to their similarity to the extracellular matrix. The main limitation regarding amino acid-based hydrogels is their difficult and expensive preparation, which can be avoided by using poly(aspartamide) (PASP)-based hydrogels. PASP-based materials can be chemically modified with various bioactive molecules for the final application purpose. In this study, dopamine containing PASP-based scaffolds is investigated, since dopamine influences several cell biological processes, such as adhesion, migration, proliferation, and differentiation, according to the literature. Periodontal ligament cells (PDLCs) of neuroectodermal origin and SH-SY5Y neuroblastoma cell line were used for the in vitro experiments. The chemical structure of the polymers and hydrogels was proved by 1H-NMR and FTIR spectroscopy. Scanning electron microscopical (SEM) images confirmed the suitable pore size range of the hydrogels for cell migration. Cell viability assay was carried out according to a standardized protocol using the WST-1 reagent. To visualize three-dimensional cell distribution in the hydrogel matrix, two-photon microscopy was used. According to our results, dopamine containing PASP gels can facilitate vertical cell penetration from the top of the hydrogel in the depth of around 4 cell layers (~150 μm). To quantify these observations, a detailed image analysis process was developed and firstly introduced in this paper.
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Drury, Jeanie L., Tanyarut Boontheekul i David J. Mooney. "Cellular Cross-linking of Peptide Modified Hydrogels". Journal of Biomechanical Engineering 127, nr 2 (18.11.2004): 220–28. http://dx.doi.org/10.1115/1.1865194.
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Peptide modification of hydrogel-forming materials is being widely explored as a means to regulate the phenotype of cells immobilized within the gels. Alternatively, we hypothesized that the adhesive interactions between cells and peptides coupled to the gel-forming materials would also enhance the overall mechanical properties of the gels. To test this hypothesis, alginate polymers were modified with RGDSP-containing peptides and the resultant polymer was used to encapsulate C2C12 myoblasts. The mechanical properties of these gels were then assessed as a function of both peptide and cell density using compression and tensile tests. Overall, it was found that above a critical peptide and cell density, encapsulated myoblasts were able to provide additional mechanical integrity to hydrogels composed of peptide-modified alginate. This occurred presumably by means of cell-peptide cross-linking of the alginate polymers, in addition to the usual Ca++ cross-linking. These results are potentially applicable to other polymer systems and important for a range of tissue engineering applications.
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Choe, Ranjoo, i Seok Il Yun. "Fmoc-diphenylalanine-based hydrogels as a potential carrier for drug delivery". e-Polymers 20, nr 1 (24.08.2020): 458–68. http://dx.doi.org/10.1515/epoly-2020-0050.
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AbstractSelf-assembled hydrogels from 9-fluorenylmethoxycarbonyl-modified diphenylalanine (Fmoc-FF) peptides were evaluated as potential vehicles for drug delivery. During self-assembly of Fmoc-FF, high concentrations of indomethacin (IDM) drugs were shown to be incorporated into the hydrogels. The β-sheet arrangement of peptides was found to be predominant in Fmoc-FF–IDM hydrogels regardless of the IDM content. The release mechanism for IDM displayed a biphasic profile comprising an initial hydrogel erosion-dominated stage followed by the diffusion-controlled stage. Small amounts of polyamidoamine dendrimer (PAMAM) added to the hydrogel (Fmoc-FF 0.5%–IDM 0.5%–PAMAM 0.03%) resulted in a more prolonged IDM release compared with Fmoc-FF 0.5%–IDM 0.5% hydrogel. Furthermore, these IDM-loaded hydrogels demonstrated excellent thixotropic response and injectability, which make them suitable candidates for use as injectable self-healing matrices for drug delivery.
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Belousov, Andrei, Aleksandra Patlay, Vladimir Silant’ev, Valeri V. Kovalev i Vadim Kumeiko. "Preparation of Hydrogels Based on Modified Pectins by Tuning Their Properties for Anti-Glioma Therapy". International Journal of Molecular Sciences 24, nr 1 (30.12.2022): 630. http://dx.doi.org/10.3390/ijms24010630.
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The extracellular matrix (ECM) of the central nervous system (CNS), characterized by low stiffness and predominance of carbohydrates on protein components, mediates limited cell proliferation and migration. Pectins are polysaccharides derived from plants and could be very promising for a tunable hydrogel design that mimics the neural ECM. Aiming to regulate gel structure and viscoelastic properties, we elaborated 10 variants of pectin-based hydrogels via tuning the concentration of the polymer and the number of free carboxyl groups expressed in the degree of esterification (DE). Viscoelastic properties of hydrogels varied in the range of 3 to 900 Pa for G′ and were chosen as the first criteria for the selection of variants suitable for CNS remodeling. For extended reciprocal characterization, two pairs of hydrogels were taken to test pectins with opposite DEs close to 0% and 50%, respectively, but with a similar rheology exceeding 100 Pa (G′), which was achieved by adjusting the concentration of pectin. Hydrogel swelling properties and in vitro stability, together with structure characterization using SEM and FTIR spectroscopy, displayed some differences that may sense for biomedical application. Bioassays on C6 and U87MG glioblastoma cultures testified the potential prospects of the anti-glioma activity of hydrogels developed by decreasing cell proliferation and modulating migration but supporting the high viability of neural cells.
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Bin Song, Bin Song, Tao Ke Tao Ke i Chutong Shi and Haibin Gu Chutong Shi and Haibin Gu. "Catechol/Pyrogallol-Modified Chitosan Composite Conductive Hydrogel as Strain Sensor for Human Movement Monitoring". Journal of the chemical society of pakistan 44, nr 5 (2022): 408. http://dx.doi.org/10.52568/001128/jcsp/44.05.2022.
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Conductive hydrogels have great application and development value in the field of functional materials including flexible wearable devices, electronic skin and health detectors. Herein, chitosan (CS) was firstly modified with 3,4-dihydroxybenzaldehyde and 2,3,4-trihydroxybenzaldehyde, respectively, through the Schiff base reaction and NaBH3CN reduction, and the resulting products (CCS and PCS) with improved water solubility were then used as the cross-linking agents for polyvinyl alcohol (PVA) to fabricate the corresponding CCS/PVA and PCS/PVA composite hydrogels through the freezing-thawing method. AlCl3 was further introduced into the two composite systems to give the hydrogels good conductivity. As flexible strain sensors, both CCS/PVA/AlCl3 and PCS/PVA/AlCl3 hydrogels could monitor human movements such as finger bending, wrist rotation, elbow bending, foot rotation and nodding. In addition, the conductive hydrogels can also respond regularly to small facial movements such as mouth opening-closing cycle and frowning. In general, the present CCS/PVA/AlCl3 and PCS/PVA/AlCl3 conductive hydrogels are expected to have good application prospect in smart wearable devices and other functional fields.
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Araszkiewicz, Antonina M., Eduarda P. Oliveira, Terje Svendsen, Katarzyna Drela, Piotr Rogujski, Izabela Malysz-Cymborska, Michal Fiedorowicz i in. "Manganese-Labeled Alginate Hydrogels for Image-Guided Cell Transplantation". International Journal of Molecular Sciences 23, nr 5 (23.02.2022): 2465. http://dx.doi.org/10.3390/ijms23052465.
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Cell transplantation has been studied extensively as a therapeutic strategy for neurological disorders. However, to date, its effectiveness remains unsatisfactory due to low precision and efficacy of cell delivery; poor survival of transplanted cells; and inadequate monitoring of their fate in vivo. Fortunately, different bio-scaffolds have been proposed as cell carriers to improve the accuracy of cell delivery, survival, differentiation, and controlled release of embedded stem cells. The goal of our study was to establish hydrogel scaffolds suitable for stem cell delivery that also allow non-invasive magnetic resonance imaging (MRI). We focused on alginate-based hydrogels due to their natural origin, biocompatibility, resemblance to the extracellular matrix, and easy manipulation of gelation processes. We optimized the properties of alginate-based hydrogels, turning them into suitable carriers for transplanted cells. Human adipose-derived stem cells embedded in these hydrogels survived for at least 14 days in vitro. Alginate-based hydrogels were also modified successfully to allow their injectability via a needle. Finally, supplementing alginate hydrogels with Mn ions or Mn nanoparticles allowed for their visualization in vivo using manganese-enhanced MRI. We demonstrated that modified alginate-based hydrogels can support therapeutic cells as MRI-detectable matrices.
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Poranki, D., C. Goodwin i M. Van Dyke. "Assessment of Deep Partial Thickness Burn Treatment with Keratin Biomaterial Hydrogels in a Swine Model". BioMed Research International 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/1803912.
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Partial thickness burns can advance to full thickness after initial injury due to inadequate tissue perfusion and increased production of inflammatory cytokines, which has been referred to as burn wound progression. In previous work, we demonstrated that a keratin biomaterial hydrogel appeared to reduce burn wound progression. In the present study, we tested the hypothesis that a modified keratin hydrogel could reduce burn wound progression and speed healing. Standardized burn wounds were created in Yorkshire swine and treated within 30 minutes with keratin hydrogel (modified and unmodified), collagen hydrogel, or silver sulfadiazine (SSD). Digital images of each wound were taken for area measurements immediately prior to cleaning and dressing changes. Wound tissue was collected and assessed histologically at several time points. Wound area showed a significant difference between hydrogels and SSD groups, and rates of reepithelialization at early time points showed an increase when keratin treatment was used compared to both collagen and SSD. A linear regression model predicted a time to wound closure of approximately 25 days for keratin hydrogel while SSD treatment required 35 days. There appeared to be no measurable differences between the modified and unmodified formulations of keratin hydrogels.
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Vales, Temmy Pegarro, Jun-Pil Jee, Won Young Lee, Sung Cho, Gye Myung Lee, Ho-Joong Kim i Jung Suk Kim. "Development of Poly(2-Methacryloyloxyethyl Phosphorylcholine)-Functionalized Hydrogels for Reducing Protein and Bacterial Adsorption". Materials 13, nr 4 (20.02.2020): 943. http://dx.doi.org/10.3390/ma13040943.
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A series of hydrogels with intrinsic antifouling properties was prepared via surface-functionalization of poly(2-hydroxyethyl methacrylate) [p(HEMA)]-based hydrogels with the biomembrane-mimicking zwitterionic polymer, poly(2-methacryloyloxyethyl phosphorylcholine) [p(MPC)]. The p(MPC)-modified hydrogels have enhanced surface wettability, high water content retention (61.0%–68.3%), and good transmittance (>90%). Notably, the presence of zwitterionic MPC moieties at the hydrogel surfaces lowered the adsorption of proteins such as lysozyme and bovine serum albumin (BSA) by 73%–74% and 59%–66%, respectively, and reduced bacterial adsorption by approximately 10%–73% relative to the unmodified control. The anti-biofouling properties of the p(MPC)-functionalized hydrogels are largely attributed to the dense hydration layer formed at the hydrogel surfaces by the zwitterionic moieties. Overall, the results demonstrate that biocompatible and antifouling hydrogels based on p(HEMA)-p(MPC) structures have promising potential for application in biomedical materials.
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Lan, Tianshu, Jingyi Guo, Xiaoming Bai, Zengjiong Huang, Zhimin Wei, Guicheng Du, Guoliang Yan, Lebin Weng i Xue Yi. "RGD-modified injectable hydrogel maintains islet beta-cell survival and function". Journal of Applied Biomaterials & Functional Materials 18 (styczeń 2020): 228080002096347. http://dx.doi.org/10.1177/2280800020963473.
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Objective: A potential solution for islet transplantation and drug discovery vis-à-vis treating diabetes is the production of functional islets in a three-dimensional extracellular matrix. Although several scaffold materials have been reported as viable candidates, a clinically applicable one that is injectable and can maintain long-term functionality and survival of islet pancreatic beta-cells (β-cells) is far from being established. Results: In the current study, we evaluated a ready-to-use and injectable hydrogel’s impact on β-cells’ function and viability, both in vitro and in vivo. We found that β-cells in high concentration with hydrogels functionalized via Arg-Gly-Asp (RGD) demonstrated better viability and insulin secretory capacity in vitro. Moreover, it is a biocompatible hydrogel that can maintain β-cell proliferation and vascularization without stimulating inflammation after subcutaneous injection. Meanwhile, modifying the hydrogel with RGD can maintain β-cells’ secretion of insulin, regulating the blood glucose levels of mice with streptozotocin-induced diabetes. Conclusions: Thus, these preliminary results indicate that this RGD-modified hydrogel is a potential extracellular matrix for islet transplantation at extrahepatic sites, and they also provide a reference for future tissue engineering study.
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Șerban, Mirela Violeta, Simona-Rebeca Nazarie (Ignat), Sorina Dinescu, Ionuț-Cristian Radu, Cătălin Zaharia, Elena-Alexandra Istrătoiu, Eugenia Tănasă i in. "Silk ProteinsEnriched Nanocomposite Hydrogels Based on Modified MMT Clay and Poly(2-hydroxyethyl methacrylate-co-2-acrylamido-2-methylpropane Sulfonic Acid) Display Favorable Properties for Soft Tissue Engineering". Nanomaterials 12, nr 3 (31.01.2022): 503. http://dx.doi.org/10.3390/nano12030503.
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Due to their remarkable structures and properties, three-dimensional hydrogels and nanostructured clay particles have been extensively studied and have shown a high potential for tissue engineering as solutions for tissue defects. In this study, four types of 2-hydroxyethyl methacrylate/2-acrylamido-2-methylpropane sulfonic acid/montmorillonite (HEMA/AMPSA/MMT) hydrogels enriched with sericin, and fibroin were prepared and studied in the context of regenerative medicine for soft tissue regenerative medicine. Our aim was to obtain crosslinked hydrogel structures using modified montmorillonite clay as a crosslinking agent. In order to improve the in vitro and in vivo biocompatibility, silk proteins were further incorporated within the hydrogel matrix. Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) were performed to prove the chemical structures of the modified MMT and nanocomposite hydrogels. Swelling and rheological measurements showed the good elastic behavior of the hydrogels due to this unique network structure in which modified MMT acts as a crosslinking agent. Hydrogel biocompatibility was assessed by MTT, LDH and LIVE/DEAD assays. The hydrogels were evaluated for their potential to support adipogenesis in vitro and human stem cells isolated from adipose tissue were seeded in them and induced to differentiate. The progress was assessed by evaluation of expression of adipogenic markers (ppar-γ2, perilipin) evaluated by qPCR. The potential of the materials to support tissue regeneration was further evaluated on animal models in vivo. All materials proved to be biocompatible, with better results on the 95% HEMA 5% AMPSA enriched with sericin and fibroin material. This composition promoted a better development of adipogenesis compared to the other compositions studied, due the addition of sericin and fibroin. The results were confirmed in vivo as well, with a better progress of soft tissue regeneration after implantation in mice. Therefore, hydrogel 95% HEMA 5% AMPSA enriched with sericin as well as fibroin showed the best results that recommend it for future soft tissue engineering application.
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Yang, Ning, Lu Shi, Yi Bin Guo, Hao Zhang i Li Chen. "Heparin Modified Temperature-Sensitive Hydrogels and Biocompatibility Research". Materials Science Forum 809-810 (grudzień 2014): 527–32. http://dx.doi.org/10.4028/www.scientific.net/msf.809-810.527.
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Chitosan/Heparin (CS/Hep) modified temperature sensitive hydrogels of γ-PGA were prepared by layer-by-layer self-assembly process. The chemical structure of the hydrogels and the surface elements were characterized by FT-IR spectrograph, XPS and TBO staining. The biocompatibility of the CS/Hep modified ploy (γ-PGA-co-NIPAAm) hydrogels were analyzed by the experiments of cell adhesion, cell proliferation and low-temperature induced cell detachment. A temperature-sensitive hydrogels carrier that could specific binding to growth factor was prepared in this research.
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Lu, Jingqiong, Yinhui Li, Deng Hu, Xiaoling Chen, Yongmei Liu, Liping Wang i Yansheng Zhao. "Synthesis and Properties of pH-, Thermo-, and Salt-Sensitive Modified Poly(aspartic acid)/Poly(vinyl alcohol) IPN Hydrogel and Its Drug Controlled Release". BioMed Research International 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/236745.
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Modified poly(aspartic acid)/poly(vinyl alcohol) interpenetrating polymer network (KPAsp/PVA IPN) hydrogel for drug controlled release was synthesized by a simple one-step method in aqueous system using poly(aspartic acid) grafting 3-aminopropyltriethoxysilane (KH-550) and poly(vinyl alcohol) (PVA) as materials. The hydrogel surface morphology and composition were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The thermal stability was analyzed by thermogravimetric analysis (TGA). The swelling properties and pH, temperature, and salt sensitivities of KPAsp, KPAsp/PVA semi-interpenetrating polymer network (semi-IPN), and KPAsp/PVA IPN hydrogels were also investigated. All of the three hydrogels showed ampholytic pH-responsive properties, and swelling behavior was also extremely sensitive to the temperature, ionic strength, and cationic species. Finally, the drug controlled release properties of the three hydrogels were evaluated and results indicated that three hydrogels could control drug release by external surroundings stimuli. The drug controlled release properties of KPAsp/PVA IPN hydrogel are the most outstanding, and the correlative measured release profiles of salicylic acid at 37°C were 32.6 wt% at pH = 1.2 (simulated gastric fluid) and 62.5 wt% at pH = 7.4 (simulated intestinal fluid), respectively. These results indicated that KPAsp/PVA IPN hydrogels are a promising carrier system for controlled drug delivery.
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Enache, Andra-Cristina, Corneliu Cojocaru, Petrisor Samoila, Adrian Bele, Andra-Cristina Bostanaru, Mihai Mares i Valeria Harabagiu. "Evaluation of Physically and/or Chemically Modified Chitosan Hydrogels for Proficient Release of Insoluble Nystatin in Simulated Fluids". Gels 8, nr 8 (10.08.2022): 495. http://dx.doi.org/10.3390/gels8080495.
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To avoid fungal spreading in the bloodstream and internal organs, many research efforts concentrate on finding appropriate candidiasis treatment from the initial stage. This paper proposes chitosan-based physically or chemically cross-linked hydrogels aimed to provide sustained release of micronized nystatin (NYSm) antifungal drug, known for its large activity spectrum. Nystatin was demonstrated itself to provide hydrodynamic/mechanic stability to the chitosan hydrogel through hydrophobic interactions and H-bonds. For chemical cross-linking of the succinylated chitosan, a non-toxic diepoxy-functionalized siloxane compound was used. The chemical structure and composition of the hydrogels, also their morphology, were evidenced by infrared spectroscopy (FTIR), by energy dispersive X-ray (EDX) analysis and by scanning electron microscopy (SEM), respectively. The hydrogels presented mechanical properties which mimic those of the soft tissues (elastic moduli < 1 MPa), necessary to ensure matrix accommodation and bioadhesion. Maximum swelling capacities were reached by the hydrogels with higher succinic anhydride content at both pH 7.4 (429%) and pH 4.2 (471%), while higher amounts of nystatin released in the simulative immersion media (57% in acidic pH and 51% in pH 7.4) occurred from the physical cross-linked hydrogel. The release mechanism by non-swellable matrix diffusion and the susceptibility of three Candida strains make all the hydrogel formulations effective for NYSm local delivery and for combating fungal infections.
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Heger, Richard, Martin Kadlec, Monika Trudicova, Natalia Zinkovska, Jan Hajzler, Miloslav Pekar i Jiri Smilek. "Novel Hydrogel Material with Tailored Internal Architecture Modified by “Bio” Amphiphilic Components—Design and Analysis by a Physico-Chemical Approach". Gels 8, nr 2 (13.02.2022): 115. http://dx.doi.org/10.3390/gels8020115.
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Nowadays, hydrogels are found in many applications ranging from the industrial to the biological (e.g., tissue engineering, drug delivery systems, cosmetics, water treatment, and many more). According to the specific needs of individual applications, it is necessary to be able to modify the properties of hydrogel materials, particularly the transport and mechanical properties related to their structure, which are crucial for the potential use of the hydrogels in modern material engineering. Therefore, the possibility of preparing hydrogel materials with tunable properties is a very real topic and is still being researched. A simple way to modify these properties is to alter the internal structure by adding another component. The addition of natural substances is convenient due to their biocompatibility and the possibility of biodegradation. Therefore, this work focused on hydrogels modified by a substance that is naturally found in the tissues of our body, namely lecithin. Hydrogels were prepared by different types of crosslinking (physical, ionic, and chemical). Their mechanical properties were monitored and these investigations were supplemented by drying and rehydration measurements, and supported by the morphological characterization of xerogels. With the addition of natural lecithin, it is possible to modify crucial properties of hydrogels such as porosity and mechanical properties, which will play a role in the final applications.