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Journal articles on the topic 'Molecular hydrogels'
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1
Jiang, Hai Ling. "Network Structure and Water Absorption of Soil Moisture Gel by Coarse-Grained Molecular Dynamics Simulations." International Journal of Engineering Research in Africa 63 (March 30, 2023): 1–12. http://dx.doi.org/10.4028/p-r8o1xc.
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With the wide application of hydrogel materials in agriculture, forestry, flexible electronics, electronic information engineering, environmental detection, flexible electronics, information science, technology and so on, the development of various new functional hydrogel materials has gradually become one of the research hotspots. At present, the research on hydrogel materials is mainly focused on the preparation of various functional hydrogels by experimental methods, there is no fundamental understanding of the relationship between the “stimulus-response” and its inner microstructures. In this paper, the author uses the molecular dynamics simulation method to study the evolution of the hydrogel’s microscopic network structure, the relationship between microstructure and water absorption of hydrogels in the processes of water swelling and “stimulus-response”. The next generation of new super absorbent, high toughness, high strength and other functional hydrogels could be synthesized by the guide of this study, and these new hydrogels have a promising future to apply in new fields of technology such as flexible electronics, and biological medicine.
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Wang, Xinyu, Huiyuan Wang, Hongmin Zhang, Tianxi Yang, Bin Zhao, and Juan Yan. "Investigation of the Impact of Hydrogen Bonding Degree in Long Single-Stranded DNA (ssDNA) Generated with Dual Rolling Circle Amplification (RCA) on the Preparation and Performance of DNA Hydrogels." Biosensors 13, no. 7 (July 23, 2023): 755. http://dx.doi.org/10.3390/bios13070755.
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DNA hydrogels have gained significant attention in recent years as one of the most promising functional polymer materials. To broaden their applications, it is critical to develop efficient methods for the preparation of bulk-scale DNA hydrogels with adjustable mechanical properties. Herein, we introduce a straightforward and efficient molecular design approach to producing physically pure DNA hydrogel and controlling its mechanical properties by adjusting the degree of hydrogen bonding in ultralong single-stranded DNA (ssDNA) precursors, which were generated using a dual rolling circle amplification (RCA)-based strategy. The effect of hydrogen bonding degree on the performance of DNA hydrogels was thoroughly investigated by analyzing the preparation process, morphology, rheology, microstructure, and entrapment efficiency of the hydrogels for Au nanoparticles (AuNPs)–BSA. Our results demonstrate that DNA hydrogels can be formed at 25 °C with simple vortex mixing in less than 10 s. The experimental results also indicate that a higher degree of hydrogen bonding in the precursor DNA resulted in stronger internal interaction forces, a more complex internal network of the hydrogel, a denser hydrogel, improved mechanical properties, and enhanced entrapment efficiency. This study intuitively demonstrates the effect of hydrogen bonding on the preparation and properties of DNA hydrogels. The method and results presented in this study are of great significance for improving the synthesis efficiency and economy of DNA hydrogels, enhancing and adjusting the overall quality and performance of the hydrogel, and expanding the application field of DNA hydrogels.
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Chen, Yifan, Weixuan Huang, Yang Chen, Minqian Wu, Ruohan Jia, and Lijun You. "Influence of Molecular Weight of Polysaccharides from Laminaria japonica to LJP-Based Hydrogels: Anti-Inflammatory Activity in the Wound Healing Process." Molecules 27, no. 20 (October 15, 2022): 6915. http://dx.doi.org/10.3390/molecules27206915.
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In this study, polysaccharides from Laminaria japonica (LJP) were produced by the treatment of ultraviolet/hydrogen peroxide (UV/H2O2) degradation into different molecular weights. Then, the degraded LJP were used to prepare LJP/chitosan/PVA hydrogel wound dressings. As the molecular weight of LJP decreased from 315 kDa to 20 kDa, the swelling ratio of the LJP-based hydrogels rose from 14.38 ± 0.60 to 20.47 ± 0.42 folds of the original weight. However, the mechanical properties of LJP-based hydrogels slightly decreased. With the extension of the UV/H2O2 degradation time, the molecular weight of LJP gradually decreased, and the anti-inflammatory activities of LJP-based hydrogels gradually increased. LJP that were degraded for 60 min (60-gel) showed the best inhibition effects on proinflammatory cytokines, while the contents of TNF-α, IL-6, and IL-1β decreased by 57.33%, 44.80%, and 67.72%, respectively, compared with the Model group. The above results suggested that low Mw LJP-based hydrogels showed great potential for a wound dressing application.
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Parelius Jonášová, Eleonóra, and Bjørn Torger Stokke. "Morpholino Target Molecular Properties Affect the Swelling Process of Oligomorpholino-Functionalized Responsive Hydrogels." Polymers 12, no. 2 (January 26, 2020): 268. http://dx.doi.org/10.3390/polym12020268.
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Responsive hydrogels featuring DNA as a functional unit are attracting increasing interest due to combination of versatility and numerous applications. The possibility to use nucleic acid analogues opens for further customization of the hydrogels. In the present work, the commonly employed DNA oligonucleotides in DNA-co-acrylamide responsive hydrogels are replaced by Morpholino oligonucleotides. The uncharged backbone of this nucleic acid analogue makes it less susceptible to possible enzymatic degradation. In this work we address fundamental issues related to key processes in the hydrogel response; such as partitioning of the free oligonucleotides and the strand displacement process. The hydrogels were prepared at the end of optical fibers for interferometric size monitoring and imaged using confocal laser scanning microscopy of the fluorescently labeled free oligonucleotides to observe their apparent diffusion and accumulation within the hydrogels. Morpholino-based hydrogels’ response to Morpholino targets was compared to DNA hydrogels’ response to DNA targets of the same base-pair sequence. Non-binding targets were observed to be less depleted in Morpholino hydrogels than in DNA hydrogels, due to their electroneutrality, resulting in faster kinetics for Morpholinos. The electroneutrality, however, also led to the total swelling response of the Morpholino hydrogels being smaller than that of DNA, since their lack of charges eliminates swelling resulting from the influx of counter-ions upon oligonucleotide binding. We have shown that employing nucleic acid analogues instead of DNA in hydrogels has a profound effect on the hydrogel response.
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Yao, Xue, Xue Gang Luo, and Ben Chao Han. "Synthesis and Characteristics of Interpenetrating Polymer Network Hydrogels Based on Konjac Glucomannan with Different Molecular Weights and Poly(acrylic acid)." Advanced Materials Research 393-395 (November 2011): 1004–7. http://dx.doi.org/10.4028/www.scientific.net/amr.393-395.1004.
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Konjac glucomannan with different molecular weights/poly(acrylic acid) hydrogels were prepared in this paper. The structure of the IPN hydrogels was characterized by FT-IR and SEM. The swelling ratio of these hydrogels showed they had pH-sensitive properties and the enzymatic degradation tests showed the hydrogels retain the enzymatic degradation character of KGM. Furthermore, hydrogel composed of native KGM degraded sharply in enzymatic degradation test and it had bigger swelling ratio and weight loss ratio than those hydrogels which composed of lower molecular weights KGM. Therefore, hydrogels composed of lower molecular weight might release drug more stable when they were used as drug carrier.
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Jiang, Yuheng, Ying Wang, Qin Li, Chen Yu, and Wanli Chu. "Natural Polymer-based Stimuli-responsive Hydrogels." Current Medicinal Chemistry 27, no. 16 (June 4, 2020): 2631–57. http://dx.doi.org/10.2174/0929867326666191122144916.
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The abilities of intelligent polymer hydrogels to change their structure and volume phase in response to external stimuli have provided new possibilities for various advanced technologies and great research and application potentials in the medical field. The natural polymer-based hydrogels have the advantages of environment-friendliness, rich sources and good biocompatibility. Based on their responsiveness to external stimuli, the natural polymer-based hydrogels can be classified into the temperature-responsive hydrogel, pH-responsive hydrogel, light-responsive hydrogel, electricresponsive hydrogel, redox-responsive hydrogel, enzyme-responsive hydrogel, magnetic-responsive hydrogel, multi-responsive hydrogel, etc. In this review, we have compiled some recent studies on natural polymer-based stimuli-responsive hydrogels, especially the hydrogels prepared from polysaccharides. The preparation methods, properties and applications of these hydrogels in the medical field are highlighted.
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Drozdova, Maria, Marina Vodyakova, Tatiana Tolstova, Marina Chernogortseva, Nikita Sazhnev, Tatiana Demina, Nadezhda Aksenova, Peter Timashev, Nataliya Kildeeva, and Elena Markvicheva. "Composite Hydrogels Based on Cross-Linked Chitosan and Low Molecular Weight Hyaluronic Acid for Tissue Engineering." Polymers 15, no. 10 (May 19, 2023): 2371. http://dx.doi.org/10.3390/polym15102371.
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The objectives of the study were as follows: (1) to develop two methods for the preparation of macroporous composite chitosan/hyaluronic acid (Ch/HA) hydrogels based on covalently cross-linked Ch and low molecular weight (Mw) HA (5 and 30 kDa); (2) to investigate some properties (swelling and in vitro degradation) and structures of the hydrogels; (3) to evaluate the hydrogels in vitro as potential biodegradable matrices for tissue engineering. Chitosan was cross-linked with either genipin (Gen) or glutaraldehyde (GA). Method 1 allowed the distribution of HA macromolecules within the hydrogel (bulk modification). In Method 2, hyaluronic acid formed a polyelectrolyte complex with Ch over the hydrogel surface (surface modification). By varying compositions of the Ch/HA hydrogels, highly porous interconnected structures (with mean pore sizes of 50–450 μm) were fabricated and studied using confocal laser scanning microscopy (CLSM). Mouse fibroblasts (L929) were cultured in the hydrogels for 7 days. Cell growth and proliferation within the hydrogel samples were studied via MTT-assay. The entrapment of low molecular weight HA was found to result in an enhancement of cell growth in the Ch/HA hydrogels compared to that in the Ch matrices. The Ch/HA hydrogels after bulk modification promoted better cell adhesion, growth and proliferation than the samples prepared by using Method 2 (surface modification).
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Dannert, Corinna, Bjørn Torger Stokke, and Rita S. Dias. "Nanoparticle-Hydrogel Composites: From Molecular Interactions to Macroscopic Behavior." Polymers 11, no. 2 (February 6, 2019): 275. http://dx.doi.org/10.3390/polym11020275.
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Hydrogels are materials used in a variety of applications, ranging from tissue engineering to drug delivery. The incorporation of nanoparticles to yield composite hydrogels has gained substantial momentum over the years since these afford tailor-making and extend material mechanical properties far beyond those achievable through molecular design of the network component. Here, we review different procedures that have been used to integrate nanoparticles into hydrogels; the types of interactions acting between polymers and nanoparticles; and how these underpin the improved mechanical and optical properties of the gels, including the self-healing ability of these composite gels, as well as serving as the basis for future development. In a less explored approach, hydrogels have been used as dispersants of nanomaterials, allowing a larger exposure of the surface of the nanomaterial and thus a better performance in catalytic and sensor applications. Furthermore, the reporting capacity of integrated nanoparticles in hydrogels to assess hydrogel properties, such as equilibrium swelling and elasticity, is highlighted.
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Vigata, Margaux, Christoph Meinert, Nathalie Bock, Bronwin L. Dargaville, and Dietmar W. Hutmacher. "Deciphering the Molecular Mechanism of Water Interaction with Gelatin Methacryloyl Hydrogels: Role of Ionic Strength, pH, Drug Loading and Hydrogel Network Characteristics." Biomedicines 9, no. 5 (May 19, 2021): 574. http://dx.doi.org/10.3390/biomedicines9050574.
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Water plays a primary role in the functionality of biomedical polymers such as hydrogels. The state of water, defined as bound, intermediate, or free, and its molecular organization within hydrogels is an important factor governing biocompatibility and hemocompatibility. Here, we present a systematic study of water states in gelatin methacryloyl (GelMA) hydrogels designed for drug delivery and tissue engineering applications. We demonstrate that increasing ionic strength of the swelling media correlated with the proportion of non-freezable bound water. We attribute this to the capability of ions to create ion–dipole bonds with both the polymer and water, thereby reinforcing the first layer of polymer hydration. Both pH and ionic strength impacted the mesh size, having potential implications for drug delivery applications. The mechanical properties of GelMA hydrogels were largely unaffected by variations in ionic strength or pH. Loading of cefazolin, a small polar antibiotic molecule, led to a dose-dependent increase of non-freezable bound water, attributed to the drug’s capacity to form hydrogen bonds with water, which helped recruit water molecules in the hydrogels’ first hydration layer. This work enables a deeper understanding of water states and molecular arrangement at the hydrogel–polymer interface and how environmental cues influence them.
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Ščeglovs, Artemijs, and Kristine Salma-Ancane. "Novel Hydrogels and Composite Hydrogels Based on ԑ-Polylysine, Hyaluronic Acid and Hydroxyapatite." Key Engineering Materials 850 (June 2020): 242–48. http://dx.doi.org/10.4028/www.scientific.net/kem.850.242.
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At this work hydrogel and composite hydrogel systems based on ԑ-polylysine (EPL), hyaluronic acid (HA) and nanocrystalline hydroxyapatite (nHAp) were synthesized via chemical cross-linking method followed by in situ precipitation of nHAp into hydrogel copolymer matrix. Molecular structure, phase composition and morphology of EPL-HA and EPL-HA/nHAp systems were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray powder diffractometry (XRD) and scanning electron microscopy (SEM). The fabricated hydrogels and composite hydrogels were evaluated by hydrogels characteristics such as gel fraction and swelling behavior. This study provides a new insight to develop cutting-edge bioactive hydrogels and composite hydrogels for bone tissue engineering as injectable biomaterials due to beneficial properties of system components.
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Craciun, Anda M. "Cinnamyl-Imine-Chitosan Hydrogels. Morphology Control." Acta Chemica Iasi 26, no. 2 (December 1, 2018): 221–32. http://dx.doi.org/10.2478/achi-2018-0014.
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Abstract The study deals with the exploration of the possibilities to control the morphology of cinnamyl-imine-chitosan hydrogels in view of their bio-application. Three series of hydrogels were synthetized from chitosan of three different molecular weights and cinnamaldehyde, varying the molar ratio between the amine groups on chitosan and aldehyde functional groups. The hydrogel morphology has been monitored by scanning electron microscopy. The variation of the hydrogel morphology as a function of chitosan molecular weight, crosslinking degree, and incubation conditions has been monitored. It was concluded that there are multiple possibilities of tuning the morphology of these hydrogels in function of the targeted application.
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Park, Sunjae, Soo-In Kim, Joo-Hee Choi, Se-Eun Kim, Seung-Ho Choe, Youngjun Son, Tae-woong Kang, Jeong-Eun Song, and Gilson Khang. "Evaluation of Silk Fibroin/Gellan Gum Hydrogels with Controlled Molecular Weight through Silk Fibroin Hydrolysis for Tissue Engineering Application." Molecules 28, no. 13 (July 5, 2023): 5222. http://dx.doi.org/10.3390/molecules28135222.
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Hydrogel is a versatile material that can be manipulated to achieve the desired physicochemical properties, such as stiffness, pore size, and viscoelasticity. Traditionally, these properties have been controlled through parameters such as concentration and pH adjustments. In this study, we focused on exploring the potential of hydrolyzed silk fibroin (HSF) as a molecular weight-modulating agent to control the physicochemical properties of double-composite hydrogels. We developed a synergistic dual-crosslinked hydrogel by combining ionically crosslinked silk fibroin with gellan gum (GG). The hydrolysis of silk fibroin not only enhanced its hydrophilicity but also enabled adjustments in its mechanical properties, including the pore size, initial modulus elasticity, and relaxation time. Moreover, biocompatibility assessments based on cell viability tests confirmed the potential of these hydrogels as biocompatible materials. By highlighting the significance of developing an HSF/GG dual-crosslinked hydrogel, this study contributes to the advancement of novel double-composite hydrogels with remarkable biocompatibility. Overall, our findings demonstrate the capability of controlling the mechanical properties of hydrogels through molecular weight modulation via hydrolysis and highlight the development of a biocompatible HSF/GG dual-crosslinked hydrogel with potential biomedical applications.
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Tavakol, Moslem, Ebrahim Vasheghani-Farahani, Mohammad Amin Mohammadifar, and Maryam Dehghan-Niri. "Effect of gamma irradiation on the physicochemical and rheological properties of enzyme-catalyzed tragacanth-based injectable hydrogels." Journal of Polymer Engineering 39, no. 5 (May 1, 2019): 442–49. http://dx.doi.org/10.1515/polyeng-2018-0366.
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Abstract In the present study, gamma irradiation was applied to promote the mechanical properties of enzyme- mediated in situ forming hydrogels prepared with tyramine-functionalized gum tragacanth (TA-GT). For this purpose, after gamma irradiation of powder or hydrocolloid solution of gum tragacanth (GT), the physiochemical and rheological properties of GT solution, and resultant hydrogel was investigated. In situ forming hydrogels were prepared via horseradish peroxidase catalyzed coupling reaction of TA-GT in the presence of hydrogen peroxide. Gamma irradiation led to a decrease in GT molecular weight and solution viscosity. Also, the solubility of GT improved and the separation of water soluble/swellable part of gum samples became easier, using gamma irradiation. In addition, by gamma irradiation of GT powder at doses of 5–15 kGy, a polymeric solution with higher concentration could be prepared that resulted in the promotion of hydrogels storage modulus. Further increase of irradiation dose did not improve storage modulus due to the extra decrease of gum molecular weight.
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Pereira, Alfredo, Elizabeth Valdés-Muñoz, Adolfo Marican, Gustavo Cabrera-Barjas, Sekar Vijayakumar, Oscar Valdés, Diana Rafael, et al. "Rational Design of Hydrogels for Cationic Antimicrobial Peptide Delivery: A Molecular Modeling Approach." Pharmaceutics 15, no. 2 (January 31, 2023): 474. http://dx.doi.org/10.3390/pharmaceutics15020474.
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In light of the growing bacterial resistance to antibiotics and in the absence of the development of new antimicrobial agents, numerous antimicrobial delivery systems over the past decades have been developed with the aim to provide new alternatives to the antimicrobial treatment of infections. However, there are few studies that focus on the development of a rational design that is accurate based on a set of theoretical-computational methods that permit the prediction and the understanding of hydrogels regarding their interaction with cationic antimicrobial peptides (cAMPs) as potential sustained and localized delivery nanoplatforms of cAMP. To this aim, we employed docking and Molecular Dynamics simulations (MDs) that allowed us to propose a rational selection of hydrogel candidates based on the propensity to form intermolecular interactions with two types of cAMPs (MP-L and NCP-3a). For the design of the hydrogels, specific building blocks were considered, named monomers (MN), co-monomers (CM), and cross-linkers (CL). These building blocks were ranked by considering the interaction with two peptides (MP-L and NCP-3a) as receptors. The better proposed hydrogel candidates were composed of MN3-CM7-CL1 and MN4-CM5-CL1 termed HG1 and HG2, respectively. The results obtained by MDs show that the biggest differences between the hydrogels are in the CM, where HG2 has two carboxylic acids that allow the forming of greater amounts of hydrogen bonds (HBs) and salt bridges (SBs) with both cAMPs. Therefore, using theoretical-computational methods allowed for the obtaining of the best virtual hydrogel candidates according to affinity with the specific cAMP. In conclusion, this study showed that HG2 is the better candidate for future in vitro or in vivo experiments due to its possible capacity as a depot system and its potential sustained and localized delivery system of cAMP.
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Timofejeva, Anna, and Dagnija Loca. "Hydroxyapatite/Polyvinyl Alcohol Composite Hydrogels for Bone and Cartilage Tissue Engineering." Key Engineering Materials 762 (February 2018): 54–58. http://dx.doi.org/10.4028/www.scientific.net/kem.762.54.
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Composite hydrogels on the basis of hydroxyapatite (HAp) and polyvinyl alcohol (PVA) has been proposed as a promising materials for bone and cartilage tissue engineering. HAp/PVA composite hydrogels with phase ratio 50:50wt% and 70:30wt% were obtained via in situ wet chemical precipitation technique in combination with the freeze-thawing approach. The XRD studies of sintered products revealed that HAp/PVA composite hydrogels synthesized from PVA with degree of hydrolysis (DH) 98% and molecular weights (MW) 25 kDa and 78 kDa are more suitable for biomedical purposes due to the formation of stoichiometric HAp. Swelling studies indicated that HAp/PVA 50:50 (78 kDa, 88% and 98%) hydrogels after 24h of immersion swell ~4.25-6.5 times less than identical samples with phase composition of 70:30wt%, which is accounted to different number of intermolecular hydrogen bonds formed. After 16 subsequent freeze-thawing cycles (FTC), HAp/PVA 50:50 (78 kDa, 88% and 98%) hydrogels contain ~1.2 times higher content of crosslinked PVA than HAp/PVA 70:30 (78 kDa, 88% and 98%) hydrogel samples.
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Byrne, Mark E., Kinam Park, and Nicholas A. Peppas. "Molecular imprinting within hydrogels." Advanced Drug Delivery Reviews 54, no. 1 (January 2002): 149–61. http://dx.doi.org/10.1016/s0169-409x(01)00246-0.
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Skopinska-Wisniewska, Joanna, Silvia De la Flor, and Justyna Kozlowska. "From Supramolecular Hydrogels to Multifunctional Carriers for Biologically Active Substances." International Journal of Molecular Sciences 22, no. 14 (July 9, 2021): 7402. http://dx.doi.org/10.3390/ijms22147402.
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Supramolecular hydrogels are 3D, elastic, water-swelled materials that are held together by reversible, non-covalent interactions, such as hydrogen bonds, hydrophobic, ionic, host–guest interactions, and metal–ligand coordination. These interactions determine the hydrogels’ unique properties: mechanical strength; stretchability; injectability; ability to self-heal; shear-thinning; and sensitivity to stimuli, e.g., pH, temperature, the presence of ions, and other chemical substances. For this reason, supramolecular hydrogels have attracted considerable attention as carriers for active substance delivery systems. In this paper, we focused on the various types of non-covalent interactions. The hydrogen bonds, hydrophobic, ionic, coordination, and host–guest interactions between hydrogel components have been described. We also provided an overview of the recent studies on supramolecular hydrogel applications, such as cancer therapy, anti-inflammatory gels, antimicrobial activity, controlled gene drug delivery, and tissue engineering.
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Cheng, Qiuhong, Zhuoer Wang, Aiyou Hao, Pengyao Xing, and Yanli Zhao. "Aromatic vapor responsive molecular packing rearrangement in supramolecular gels." Materials Chemistry Frontiers 4, no. 8 (2020): 2452–61. http://dx.doi.org/10.1039/d0qm00348d.
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Aromatic vapor responsive hydrogels are prepared by crystal transformation of commercially available β-cyclodextrin (β-CD). Hydrogel composites coassembled by clay with β-CD show haze evolution toward aromatic vapor under heating–cooling treatment.
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Sanaeifar, Niuosha, Karsten Mäder, and Dariush Hinderberger. "Molecular-Level Release of Coumarin-3-Carboxylic Acid and Warfarin-Derivatives from BSA-Based Hydrogels." Pharmaceutics 13, no. 10 (October 11, 2021): 1661. http://dx.doi.org/10.3390/pharmaceutics13101661.
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This investigation aimed at developing BSA hydrogels as a controlled release system to study the release behavior of spin-labeled coumarin-3-carboxylic acid (SL-CCS) and warfarin (SL-WFR). The release profiles of these spin-labeled (SL-) pharmaceuticals from BSA hydrogels prepared with different procedures are compared in detail. The mechanical properties of the gels during formation and release were studied via rheology, while a nanoscopic view on the release behavior was achieved by analyzing SL-drugs–BSA interaction using continuous wave electron paramagnetic resonance (CW EPR) spectroscopy. The influence of type of drug, drug concentration, duration of gel formation, and gelation methods on release behavior were characterized by CW EPR spectroscopy, EPR imaging (EPRI), and dynamic light scattering (DLS), which provide information on the interaction of BSA with SL-drugs, the percentage of drug inside the hydrogel and the nature and size of the released structures, respectively. We found that the release rate of SL-CCS and SL-WFR from BSA hydrogels is tunable through drug ratios, hydrogel incubation time and gelation procedures. All of the results indicate that BSA hydrogels can be potentially exploited in controlled drug delivery applications.
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Ohsedo, Yutaka, and Mayumi Sasaki. "Polymeric Hydrogelator-Based Molecular Gels Containing Polyaniline/Phosphoric Acid Systems." Gels 8, no. 8 (July 27, 2022): 469. http://dx.doi.org/10.3390/gels8080469.
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To expand the range of applications of hydrogels, researchers are interested in developing novel molecular hydrogel materials that have affinities for the living body and the ability to mediate electrical signals. In this study, a simple mixing method for creating a novel composite molecular gel is employed, which combines a hydrophilic conductive polymer, a polyaniline/phosphoric acid complex, and a polymer hydrogelator as a matrix. The composite hydrogel showed an improved gel-forming ability; more effective mechanical properties, with an increased strain value at the sol–gel transition point compared to the single system, which may be sufficient for paintable gel; and a better electrochemical response, due to the electrically conducting polyaniline component. These findings demonstrate the applicability of the new composite hydrogels to new potential paintable electrode materials.
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Yang, Xin, Bronwin Dargaville, and Dietmar Hutmacher. "Elucidating the Molecular Mechanisms for the Interaction of Water with Polyethylene Glycol-Based Hydrogels: Influence of Ionic Strength and Gel Network Structure." Polymers 13, no. 6 (March 10, 2021): 845. http://dx.doi.org/10.3390/polym13060845.
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The interaction of water within synthetic and natural hydrogel systems is of fundamental importance in biomaterial science. A systematic study is presented on the swelling behavior and states of water for a polyethylene glycol-diacrylate (PEGDA)-based model neutral hydrogel system that goes beyond previous studies reported in the literature. Hydrogels with different network structures are crosslinked and swollen in different combinations of water and phosphate-buffered saline (PBS). Network variables, polyethylene glycol (PEG) molecular weight (MW), and weight fraction are positively correlated with swelling ratio, while “non-freezable bound water” content decreases with PEG MW. The presence of ions has the greatest influence on equilibrium water and “freezable” and “non-freezable” water, with all hydrogel formulations showing a decreased swelling ratio and increased bound water as ionic strength increases. Similarly, the number of “non-freezable bound water” molecules, calculated from DSC data, is greatest—up to six molecules per PEG repeat unit—for gels swollen in PBS. Fundamentally, the balance of osmotic pressure and non-covalent bonding is a major factor within the molecular structure of the hydrogel system. The proposed model explains the dynamic interaction of water within hydrogels in an osmotic environment. This study will point toward a better understanding of the molecular nature of the water interface in hydrogels.
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Kim, Yong Tae, Sara Bohjanen, Nirveek Bhattacharjee, and Albert Folch. "Partitioning of hydrogels in 3D-printed microchannels." Lab on a Chip 19, no. 18 (2019): 3086–93. http://dx.doi.org/10.1039/c9lc00535h.
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We demonstrated a stereolithographically 3D-printed chip for the straightforward injection of hydrogel barriers in microchannels and the facile measurement of molecular diffusivities through these hydrogels.
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Zhang, Meng, Karen C. Waldron, and X. X. Zhu. "Formation of molecular hydrogels from a bile acid derivative and selected carboxylic acids." RSC Advances 6, no. 42 (2016): 35436–40. http://dx.doi.org/10.1039/c6ra04536g.
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Ooi, Huey Wen, Hui Peng, Kevin S. Jack, and Andrew K. Whittaker. "Understanding the Diffusion of Dextrans in ‘Click' PNIPAAm Hydrogels." Australian Journal of Chemistry 67, no. 1 (2014): 85. http://dx.doi.org/10.1071/ch13333.
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Arguably the most important property of a hydrogel is the ability to allow the diffusion of solutes through the crosslinked network. Studies of the diffusion in hydrogels are important for providing information on the rate and extent of the passage of the solute and on the details of the microstructure of the hydrogel. Such knowledge is directly relevant for applications such as controlled drug delivery systems. The structure of novel poly(N-isopropylacrylamide) (PNIPAAm) hydrogels can be revealed by the restricted diffusion of appropriate probe molecules. Dextran molecules, labelled with fluorescent moieties, were incorporated into well-defined PNIPAAm hydrogels to investigate the effects of hydrogel mesh size and dextran molecular size on the diffusivities of solute molecules.
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Kędzierska, Magdalena, Mateusz Jamroży, Anna Drabczyk, Sonia Kudłacik-Kramarczyk, Magdalena Bańkosz, Mateusz Gruca, Piotr Potemski, and Bożena Tyliszczak. "Analysis of the Influence of Both the Average Molecular Weight and the Content of Crosslinking Agent on Physicochemical Properties of PVP-Based Hydrogels Developed as Innovative Dressings." International Journal of Molecular Sciences 23, no. 19 (October 1, 2022): 11618. http://dx.doi.org/10.3390/ijms231911618.
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Hydrogels belong to the group of polymers with a three-dimensional crosslinked structure, and their crosslinking density strongly affects their physicochemical properties. Here, we verified the impact of both the average molecular weight of crosslinking agents used during the photopolymerization of hydrogels and that of their content on selected properties of these materials. First, PVP-based hydrogels modified with Aloe vera juice and L-ascorbic acid were prepared using UV radiation. Next, their surface morphology was characterized via optical scanning electron microscopy, whereas their chemical structure was investigated by FT-IR spectroscopy. Moreover, we verified the tendency of the hydrogels to degrade in selected physiological liquids, as well as their tensile strength, percentage of elongation, and swelling capability. We found that the more crosslinking agent in the hydrogel matrix, the higher its tensile strength and the less elongation. The hydrogels showed the highest stability during incubation in SBF and 2% hemoglobin solution. A sharp decrease in the pH of distilled water observed during the incubation of the hydrogels was probably due to the release of Aloe vera juice from the hydrogel matrices. This was additionally confirmed by the decrease in the intensity of the absorption band derived from the polysaccharides included in this additive and by the decrease in the swelling ratio after 48 h. Importantly, all hydrogels demonstrated swelling properties, and it was proven that the higher content of the crosslinking agent in hydrogels, the lower their swelling ability.
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Mayorova, Oksana A., Ben C. N. Jolly, Roman A. Verkhovskii, Valentina O. Plastun, Olga A. Sindeeva, and Timothy E. L. Douglas. "pH-Sensitive Dairy-Derived Hydrogels with a Prolonged Drug Release Profile for Cancer Treatment." Materials 14, no. 4 (February 5, 2021): 749. http://dx.doi.org/10.3390/ma14040749.
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A novel versatile biocompatible hydrogel of whey protein isolate (WPI) and two types of tannic acid (TAs) was prepared by crosslinking of WPI with TAs in a one-step method at high temperature for 30 min. WPI is one common protein-based preparation which is used for hydrogel formation. The obtained WPI-TA hydrogels were in disc form and retained their integrity after sterilization by autoclaving. Two TA preparations of differing molecular weight and chemical structure were compared, namely a polygalloyl glucose-rich extract-ALSOK 02-and a polygalloyl quinic acid-rich extract-ALSOK 04. Hydrogel formation was observed for WPI solutions containing both preparations. The swelling characteristics of hydrogels were investigated at room temperature at different pH values, namely 5, 7, and 9. The swelling ability of hydrogels was independent of the chemical structure of the added TAs. A trend of decrease of mass increase (MI) in hydrogels was observed with an increase in the TA/WPI ratio compared to the control WPI hydrogel without TA. This dependence (a MI decrease-TA/WPI ratio) was observed for hydrogels with different types of TA both in neutral and acidic conditions (pH 5.7). Under alkaline conditions (pH 9), negative values of swelling were observed for all hydrogels with a high content of TAs and were accompanied by a significant release of TAs from the hydrogel network. Our studies have shown that the release of TA from hydrogels containing ALSOK04 is higher than from hydrogels containing ALSOK 02. Moreover, the addition of TAs, which display a strong anti-cancer effect, increases the cytotoxicity of WPI-TAs hydrogels against the Hep-2 human laryngeal squamous carcinoma (Hep-2 cells) cell line. Thus, WPI-TA hydrogels with prolonged drug release properties and cytotoxicity effect can be used as anti-cancer scaffolds.
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Vilaça, Helena, André Carvalho, Tarsila Castro, Elisabete M. S. Castanheira, Loic Hilliou, Ian Hamley, Manuel Melle-Franco, Paula M. T. Ferreira, and José A. Martins. "Unveiling the Role of Capping Groups in Naphthalene N-Capped Dehydrodipeptide Hydrogels." Gels 9, no. 6 (June 6, 2023): 464. http://dx.doi.org/10.3390/gels9060464.
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Self-assembled peptide-based hydrogels are archetypical nanostructured materials with a plethora of foreseeable applications in nanomedicine and as biomaterials. N-protected di- and tri-peptides are effective minimalist (molecular) hydrogelators. Independent variation of the capping group, peptide sequence and side chain modifications allows a wide chemical space to be explored and hydrogel properties to be tuned. In this work, we report the synthesis of a focused library of dehydrodipeptides N-protected with 1-naphthoyl and 2-naphthylacetyl groups. The 2-naphthylacetyl group was extensively reported for preparation of peptide-based self-assembled hydrogels, whereas the 1-naphthaloyl group was largely overlooked, owing presumably to the lack of a methylene linker between the naphthalene aromatic ring and the peptide backbone. Interestingly, dehydrodipeptides N-capped with the 1-naphthyl moiety afford stronger gels, at lower concentrations, than the 2-naphthylacetyl-capped dehydrodipeptides. Fluorescence and circular dichroism spectroscopy showed that the self-assembly of the dehydrodipeptides is driven by intermolecular aromatic π–π stacking interactions. Molecular dynamics simulations revealed that the 1-naphthoyl group allows higher order aromatic π–π stacking of the peptide molecules than the 2-naphthylacetyl group, together with hydrogen bonding of the peptide scaffold. The nanostructure of the gel networks was studied by TEM and STEM microscopy and was found to correlate well with the elasticity of the gels. This study contributes to understanding the interplay between peptide and capping group structure on the formation of self-assembled low-molecular-weight peptide hydrogels. Moreover, the results presented here add the 1-naphthoyl group to the palette of capping groups available for the preparation of efficacious low-molecular-weight peptide-based hydrogels.
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Ye, Jing, Gang Yang, Jing Zhang, Zhenghua Xiao, Ling He, Han Zhang, and Qi Liu. "Preparation and characterization of gelatin-polysaccharide composite hydrogels for tissue engineering." PeerJ 9 (March 15, 2021): e11022. http://dx.doi.org/10.7717/peerj.11022.
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Background Tissue engineering, which involves the selection of scaffold materials, presents a new therapeutic strategy for damaged tissues or organs. Scaffold design based on blends of proteins and polysaccharides, as mimicry of the native extracellular matrix, has recently become a valuable strategy for tissue engineering. Objective This study aimed to construct composite hydrogels based on natural polymers for tissue engineering. Methods Composite hydrogels based on blends of gelatin with a polysaccharide component (chitosan or alginate) were produced and subsequently enzyme crosslinked. The other three hydrogels, chitosan hydrogel, sodium alginate hydrogel, and microbial transglutaminase-crosslinked gelatin (mTG/GA) hydrogel were also prepared. All hydrogels were evaluated for in vitro degradation property, swelling capacity, and mechanical property. Rat adipose-derived stromal stem cells (ADSCs) were isolated and seeded on (or embedded into) the above-mentioned hydrogels. The morphological features of ADSCs were observed and recorded. The effects of the hydrogels on ADSC survival and adhesion were investigated by immunofluorescence staining. Cell proliferation was tested by thiazolyl blue tetrazolium bromide (MTT) assay. Results Cell viability assay results showed that the five hydrogels are not cytotoxic. The mTG/GA and its composite hydrogels showed higher compressive moduli than the single-component chitosan and alginate hydrogels. MTT assay results showed that ADSCs proliferated better on the composite hydrogels than on the chitosan and alginate hydrogels. Light microscope observation and cell cytoskeleton staining showed that hydrogel strength had obvious effects on cell growth and adhesion. The ADSCs seeded on chitosan and alginate hydrogels plunged into the hydrogels and could not stretch out due to the low strength of the hydrogel, whereas cells seeded on composite hydrogels with higher elastic modulus, could spread out, and grew in size. Conclusion The gelatin-polysaccharide composite hydrogels could serve as attractive biomaterials for tissue engineering due to their easy preparation and favorable biophysical properties.
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Li, Yanxia, Juanjuan Tan, Lu Huang, Yiting Chen, and Qi Lin. "A Portable Visual Sensor by Molecularly Imprinted Hydrogels for HRP Recognition." Current Analytical Chemistry 16, no. 6 (August 13, 2020): 800–808. http://dx.doi.org/10.2174/1573411015666190723151351.
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Background: Molecular imprinting is a technology used to produce artificial receptors that simulate the molecular recognition in the nature and prepare the polymer network structure in the presence of template molecule. Molecularly imprinted visual sensor combines the advantages of specific recognition via molecular imprinting and fast response speed via visualization. The aims of this paper are to prepare a portable visual sensor for Horseradish Peroxidase (HRP) recognition based on molecularly imprinted hydrogel. Methods: At first, HRP-imprinted polyacrylamide hydrogels with 1 mm thickness were obtained by one-step synthesis via radical induced in-situ polymerization of acrylamide using acrylamide (AAm) as the functional monomer, N,N'-Methylenebisacrylamide (MBA) as the crosslink agent and HRP as the template molecule. Results: Compared with nonimprinted hydrogels, the HRP-imprinted hydrogel sensor showed significant color changes in response to the target HRP. This visual sensor was constructed based on 3, 3', 5, 5'- tetramethyl benzidine (TMB) - H2O2 color reaction system by HRP catalyzing to produce color change through digital photography and image analysis (RGB system). The HRP-imprinted hydrogel showed good response in the range of 0.001-0.5 mg/mL and had a significant specific recognition compared to other proteins via selective test. Conclusion: The proposed portable visual sensor could be used for qualitative and semi-quantitative analysis of HRP with high selectivity and reasonable regeneration. The sensor has the advantages of simple operation, low cost, no special equipment, and can be applied to serum sample with less sample consumption and no need of sample preparation. It has wide application prospects in microfluidic devices, biomimetic sensors, flexible biosensor and membrane separation technology.
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Lee, Seongwon, Joohee Choi, Jina Youn, Younghun Lee, Wooyoup Kim, Seungho Choe, Jeongeun Song, Rui L. Reis, and Gilson Khang. "Development and Evaluation of Gellan Gum/Silk Fibroin/Chondroitin Sulfate Ternary Injectable Hydrogel for Cartilage Tissue Engineering." Biomolecules 11, no. 8 (August 11, 2021): 1184. http://dx.doi.org/10.3390/biom11081184.
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Hydrogel is in the spotlight as a useful biomaterial in the field of drug delivery and tissue engineering due to its similar biological properties to a native extracellular matrix (ECM). Herein, we proposed a ternary hydrogel of gellan gum (GG), silk fibroin (SF), and chondroitin sulfate (CS) as a biomaterial for cartilage tissue engineering. The hydrogels were fabricated with a facile combination of the physical and chemical crosslinking method. The purpose of this study was to find the proper content of SF and GG for the ternary matrix and confirm the applicability of the hydrogel in vitro and in vivo. The chemical and mechanical properties were measured to confirm the suitability of the hydrogel for cartilage tissue engineering. The biocompatibility of the hydrogels was investigated by analyzing the cell morphology, adhesion, proliferation, migration, and growth of articular chondrocytes-laden hydrogels. The results showed that the higher proportion of GG enhanced the mechanical properties of the hydrogel but the groups with over 0.75% of GG exhibited gelling temperatures over 40 °C, which was a harsh condition for cell encapsulation. The 0.3% GG/3.7% SF/CS and 0.5% GG/3.5% SF/CS hydrogels were chosen for the in vitro study. The cells that were encapsulated in the hydrogels did not show any abnormalities and exhibited low cytotoxicity. The biochemical properties and gene expression of the encapsulated cells exhibited positive cell growth and expression of cartilage-specific ECM and genes in the 0.5% GG/3.5% SF/CS hydrogel. Overall, the study of the GG/SF/CS ternary hydrogel with an appropriate content showed that the combination of GG, SF, and CS can synergistically promote articular cartilage defect repair and has considerable potential for application as a biomaterial in cartilage tissue engineering.
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Lin, Xinyi, Borui Xu, Hong Zhu, Jinrun Liu, Alexander Solovev, and Yongfeng Mei. "Requirement and Development of Hydrogel Micromotors towards Biomedical Applications." Research 2020 (July 10, 2020): 1–15. http://dx.doi.org/10.34133/2020/7659749.
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With controllable size, biocompatibility, porosity, injectability, responsivity, diffusion time, reaction, separation, permeation, and release of molecular species, hydrogel microparticles achieve multiple advantages over bulk hydrogels for specific biomedical procedures. Moreover, so far studies mostly concentrate on local responses of hydrogels to chemical and/or external stimuli, which significantly limit the scope of their applications. Tetherless micromotors are autonomous microdevices capable of converting local chemical energy or the energy of external fields into motive forces for self-propelled or externally powered/controlled motion. If hydrogels can be integrated with micromotors, their applicability can be significantly extended and can lead to fully controllable responsive chemomechanical biomicromachines. However, to achieve these challenging goals, biocompatibility, biodegradability, and motive mechanisms of hydrogel micromotors need to be simultaneously integrated. This review summarizes recent achievements in the field of micromotors and hydrogels and proposes next steps required for the development of hydrogel micromotors, which become increasingly important for in vivo and in vitro bioapplications.
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Kuzina, S. I., I. A. Shilova, V. F. Ivanov, and A. I. Mikhailov. "Molecular mobility of nanocellulose hydrogels." Russian Journal of Physical Chemistry B 10, no. 5 (September 2016): 839–43. http://dx.doi.org/10.1134/s1990793116050067.
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Zhao, Fan, Man Lung Ma, and Bing Xu. "Molecular hydrogels of therapeutic agents." Chemical Society Reviews 38, no. 4 (2009): 883. http://dx.doi.org/10.1039/b806410p.
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Croitoriu, Alexandra, Loredana E. Nita, Aurica P. Chiriac, Alina G. Rusu, and Maria Bercea. "New Physical Hydrogels Based on Co-Assembling of FMOC–Amino Acids." Gels 7, no. 4 (November 12, 2021): 208. http://dx.doi.org/10.3390/gels7040208.
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In the last years, physical hydrogels have been widely studied due to the characteristics of these structures, respectively the non-covalent interactions and the absence of other necessary components for the cross-linking processes. Low molecular weight gelators are a class of small molecules which form higher ordered structures through hydrogen bonding and π–π interactions. In this context it is known that the formation of hydrogels based on FMOC–amino acids is determined by the primary structures of amino acids and the secondary structure arrangement (alpha–helix or beta–sheet motifs). The present study aimed to obtain supramolecular gels through co-assembly phenomenon using FMOC–amino acids as low molecular weight gelators. The stability of the new structures was evaluated by the vial inversion test, while FTIR spectra put into evidence the interaction between the compounds. The gel-like structure is evidenced by viscoelastic parameters in oscillatory shear conditions. SEM microscopy was used to obtain the visual insight into the morphology of the physical hydrogel network while DLS measurements highlighted the sol-gel transition. The molecular arrangement of gels was determined by circular dichroism, fluorescence and UV-Vis spectroscopy.
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Vitale, Mattia, Cosimo Ligorio, Ian P. Smith, Stephen M. Richardson, Judith A. Hoyland, and Jordi Bella. "Incorporation of Natural and Recombinant Collagen Proteins within Fmoc-Based Self-Assembling Peptide Hydrogels." Gels 8, no. 5 (April 21, 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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Yan, Caiping, Xingkuan Wang, Chao Xiang, Yong Wang, Chaoyu Pu, Lu Chen, Ke Jiang, and Yuling Li. "Applications of Functionalized Hydrogels in the Regeneration of the Intervertebral Disc." BioMed Research International 2021 (August 19, 2021): 1–19. http://dx.doi.org/10.1155/2021/2818624.
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Intervertebral disc degeneration (IDD) is caused by genetics, aging, and environmental factors and is one of the leading causes of low back pain. The treatment of IDD presents many challenges. Hydrogels are biomaterials that possess properties similar to those of the natural extracellular matrix and have significant potential in the field of regenerative medicine. Hydrogels with various functional qualities have recently been used to repair and regenerate diseased intervertebral discs. Here, we review the mechanisms of intervertebral disc homeostasis and degeneration and then discuss the applications of hydrogel-mediated repair and intervertebral disc regeneration. The classification of artificial hydrogels and natural hydrogels is then briefly introduced, followed by an update on the development of functional hydrogels, which include noncellular therapeutic hydrogels, cellular therapeutic hydrogel scaffolds, responsive hydrogels, and multifunctional hydrogels. The challenges faced and future developments of the hydrogels used in IDD are discussed as they further promote their clinical translation.
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Kocak, Fatma Z., Muhammad Yar, and 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, no. 10 (May 11, 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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Wei, Lai, Jianying Tan, Li Li, Huanran Wang, Sainan Liu, Junying Chen, Yajun Weng, and Tao Liu. "Chitosan/Alginate Hydrogel Dressing Loaded FGF/VE-Cadherin to Accelerate Full-Thickness Skin Regeneration and More Normal Skin Repairs." International Journal of Molecular Sciences 23, no. 3 (January 23, 2022): 1249. http://dx.doi.org/10.3390/ijms23031249.
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The process of full-thickness skin regeneration is complex and has many parameters involved, which makes it difficult to use a single dressing to meet the various requirements of the complete regeneration at the same time. Therefore, developing hydrogel dressings with multifunction, including tunable rheological properties and aperture, hemostatic, antibacterial and super cytocompatibility, is a desirable candidate in wound healing. In this study, a series of complex hydrogels were developed via the hydrogen bond and covalent bond between chitosan (CS) and alginate (SA). These hydrogels exhibited suitable pore size and tunable rheological properties for cell adhesion. Chitosan endowed hemostatic, antibacterial properties and great cytocompatibility and thus solved two primary problems in the early stage of the wound healing process. Moreover, the sustained cytocompatibility of the hydrogels was further investigated after adding FGF and VE-cadherin via the co-culture of L929 and EC for 12 days. The confocal 3D fluorescent images showed that the cells were spherical and tended to form multicellular spheroids, which distributed in about 40–60 μm thick hydrogels. Furthermore, the hydrogel dressings significantly accelerate defected skin turn to normal skin with proper epithelial thickness and new blood vessels and hair follicles through the histological analysis of in vivo wound healing. The findings mentioned above demonstrated that the CS/SA hydrogels with growth factors have great potential as multifunctional hydrogel dressings for full-thickness skin regeneration incorporated with hemostatic, antibacterial, sustained cytocompatibility for 3D cell culture and normal skin repairing.
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Ma, Haohua, Xin Qiao, and Lu Han. "Advances of Mussel-Inspired Nanocomposite Hydrogels in Biomedical Applications." Biomimetics 8, no. 1 (March 22, 2023): 128. http://dx.doi.org/10.3390/biomimetics8010128.
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Hydrogels, with 3D hydrophilic polymer networks and excellent biocompatibilities, have emerged as promising biomaterial candidates to mimic the structure and properties of biological tissues. The incorporation of nanomaterials into a hydrogel matrix can tailor the functions of the nanocomposite hydrogels to meet the requirements for different biomedical applications. However, most nanomaterials show poor dispersion in water, which limits their integration into the hydrophilic hydrogel network. Mussel-inspired chemistry provides a mild and biocompatible approach in material surface engineering due to the high reactivity and universal adhesive property of catechol groups. In order to attract more attention to mussel-inspired nanocomposite hydrogels, and to promote the research work on mussel-inspired nanocomposite hydrogels, we have reviewed the recent advances in the preparation of mussel-inspired nanocomposite hydrogels using a variety of nanomaterials with different forms (nanoparticles, nanorods, nanofibers, nanosheets). We give an overview of each nanomaterial modified or hybridized by catechol or polyphenol groups based on mussel-inspired chemistry, and the performances of the nanocomposite hydrogel after the nanomaterial’s incorporation. We also highlight the use of each nanocomposite hydrogel for various biomedical applications, including drug delivery, bioelectronics, wearable/implantable biosensors, tumor therapy, and tissue repair. Finally, the challenges and future research direction in designing mussel-inspired nanocomposite hydrogels are discussed.
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Bayer, Ilker S. "A Review of Sustained Drug Release Studies from Nanofiber Hydrogels." Biomedicines 9, no. 11 (November 4, 2021): 1612. http://dx.doi.org/10.3390/biomedicines9111612.
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Polymer nanofibers have exceptionally high surface area. This is advantageous compared to bulk polymeric structures, as nanofibrils increase the area over which materials can be transported into and out of a system, via diffusion and active transport. On the other hand, since hydrogels possess a degree of flexibility very similar to natural tissue, due to their significant water content, hydrogels made from natural or biodegradable macromolecular systems can even be injectable into the human body. Due to unique interactions with water, hydrogel transport properties can be easily modified and tailored. As a result, combining nanofibers with hydrogels would truly advance biomedical applications of hydrogels, particularly in the area of sustained drug delivery. In fact, certain nanofiber networks can be transformed into hydrogels directly without the need for a hydrogel enclosure. This review discusses recent advances in the fabrication and application of biomedical nanofiber hydrogels with a strong emphasis on drug release. Most of the drug release studies and recent advances have so far focused on self-gelling nanofiber systems made from peptides or other natural proteins loaded with cancer drugs. Secondly, polysaccharide nanofiber hydrogels are being investigated, and thirdly, electrospun biodegradable polymer networks embedded in polysaccharide-based hydrogels are becoming increasingly popular. This review shows that a major outcome from these works is that nanofiber hydrogels can maintain drug release rates exceeding a few days, even extending into months, which is an extremely difficult task to achieve without the nanofiber texture. This review also demonstrates that some publications still lack careful rheological studies on nanofiber hydrogels; however, rheological properties of hydrogels can influence cell function, mechano-transduction, and cellular interactions such as growth, migration, adhesion, proliferation, differentiation, and morphology. Nanofiber hydrogel rheology becomes even more critical for 3D or 4D printable systems that should maintain sustained drug delivery rates.
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Araiza-Verduzco, Fernanda, Eustolia Rodríguez-Velázquez, Harold Cruz, Ignacio A. Rivero, Delvis R. Acosta-Martínez, Georgina Pina-Luis, and Manuel Alatorre-Meda. "Photocrosslinked Alginate-Methacrylate Hydrogels with Modulable Mechanical Properties: Effect of the Molecular Conformation and Electron Density of the Methacrylate Reactive Group." Materials 13, no. 3 (January 22, 2020): 534. http://dx.doi.org/10.3390/ma13030534.
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Hydrogels for load-bearing biomedical applications, such as soft tissue replacement, are required to be tough and biocompatible. In this sense, alginate-methacrylate hydrogels (H-ALGMx) are well known to present modulable levels of elasticity depending on the methacrylation degree; however, little is known about the role of additional structural parameters. In this work, we present an experimental-computational approach aimed to evaluate the effect of the molecular conformation and electron density of distinct methacrylate groups on the mechanical properties of photocrosslinked H-ALGMx hydrogels. Three alginate-methacrylate precursor macromers (ALGMx) were synthesized: alginate-glycidyl methacrylate (ALGM1), alginate-2-aminoethyl methacrylate (ALGM2), and alginate-methacrylic anhydride (ALGM3). The macromers were studied by Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H-NMR), and density functional theory method (DFT) calculations to assess their molecular/electronic configurations. In parallel, they were also employed to produce H-ALGMx hydrogels, which were characterized by compressive tests. The obtained results demonstrated that tougher hydrogels were produced from ALGMx macromers presenting the C=C reactive bond with an outward orientation relative to the polymer chain and showing free rotation, which favored in conjunction the covalent crosslinking. In addition, although playing a secondary role, it was also found that the presence of acid hydrogen atoms in the methacrylate unit enables the formation of supramolecular hydrogen bonds, thereby reinforcing the mechanical properties of the H-ALGMx hydrogels. By contrast, impaired mechanical properties resulted from macromer conditions in which the C=C bond adopted an inward orientation to the polymer chain accompanied by a torsional impediment.
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Ayhan, Fatma, Sabiha Demirci, and Hakan Ayhan. "Poly (Ethylene Glycol) / Gelatin Composite Hydrogels for Drug Delivery." Journal of Composites and Biodegradable Polymers 2, no. 1 (February 5, 2014): 36–45. http://dx.doi.org/10.12974/2311-8717.2014.02.01.5.
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Hydrogels are three dimentional, hydrophilic, and polymeric networks that have been designed and fabricated to fulfill the needs of the pharmaceutical and medical fields. Many biomedical applications including controlled drug delivery have developed based on hydrogel technologies. Various composite hydrogels including synthetic and natural materials can be produced to create controllable systems in drug delivery applications. In this study, poly(ethylene glycol) (PEG-DA) based composite hydrogels were prepared by photopolymerization method and 2,2-dimethoxy-2-phenylacetophenone (DMPA) was used as photoinitiator. Macromer mixtures were prepared by mixing 30 % PEG-DA and 0.5 % DMPA. Photocuring was achieved by cross-linking with 3 % ethylene glycol diacrylate (EGDMA) after addition of drug and gelatin solutions under mild conditions. The effect of gelatin concentration and molecular weight on the gentamicin release was studied with 75, 100, 225, and 300 bloom gelatin for 0.1, 0.5, and 1.0 w/w ratios. Drug release kinetics from loaded composite hydrogels were tested by spectrophotometric method in phosphate (pH 7.4) and citrate buffer (pH 1.2) representing small intestine and stomach media, respectively. New biopolymer containing composite hydrogels enhanced drug release rates for all compositions and gentamicin release was found to be adversely effected by concentration and molecular weight. Hydrogels were morphologically characterized by SEM images which indicated the presence of pinholes like structures with smaller sizes for larger molecular weights.
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Wang, Xiaohui, Qingqing Dai, Haoquan Zhong, Xinxin Liu, and Junli Ren. "Fast-responsive temperature-sensitive hydrogels." BioResources 14, no. 4 (September 12, 2019): 8543–58. http://dx.doi.org/10.15376/biores.14.4.8543-8558.
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Temperature fast-responsive and magnetic poly(N-isopropylacrylamide-co-acrylamide) (CMX-MNP-PNIPAm/Fe3O4) hydrogels were developed using carboxymethyl xylan (CMX) as a pore-forming agent and a NaCl solution as the reaction medium, followed by fabricating Fe3O4 nanoparticles in situ within the hydrogel matrix. It was found that NaCl played a role in the phase separation and was used as the electrolyte to shield CMX molecular chains. The obtained hydrogels exhibited a fast, temperature-responsive behavior, and the water retention was less than 15% for 1 min under 60 °C. The prepared hydrogels showed enhanced mechanical properties and magnetic properties due to the presence of Fe3O4 particles. The lower critical solution temperature of the hydrogels was in the range of 35 to 39 °C, which was acquired through adjusting the amount of hydrophilic monomer (AM). The magnetic and thermosensitive hydrogel had the attractive photothermal conversion ability and could be heated to 40 °C within 2 min, and to 69 °C within 7 min under near infrared irradiation.
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Balçık Tamer, Yasemin. "A New Design of Poly(N-Isopropylacrylamide) Hydrogels Using Biodegradable Poly(Beta-Aminoester) Crosslinkers as Fertilizer Reservoirs for Agricultural Applications." Gels 9, no. 2 (February 3, 2023): 127. http://dx.doi.org/10.3390/gels9020127.
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Poly(N-isopropylacrylamide) (P(NIPAAm)) hydrogels were prepared by free-radical polymerization with biodegradable poly (β-amino ester) (PBAE) crosslinkers at 1 wt% and 3 wt% ratio, and compared with conventional N,N′-methylene bisacrylamide (MBA)-crosslinked hydrogel. The influence of the type, molecular weight, and diacrylate/amine ratio of the crosslinker on the crosslink density, compressive strength, and swelling and biodegradation behavior of the hydrogels was investigated. The hydrogels synthesized with lower molecular weight PBAE crosslinkers showed higher crosslinking degrees and compressive strength and lower swelling ratios. To reveal the controlled release behavior of the fertilizer, KNO3 was used as the model, and its loading and release behavior from these hydrogels was also examined. The N/T5/1 sample with 1.5/1.0 diacrylate/amine molar ratio and 1 wt% PBAE ratio demonstrated the most controlled release of KNO3 with 66.9% after 18 days in soil. In addition, the hydrogel with the porosity of 71.65% and crosslinking degree of 2.85 × 10−5 mol cm−3 showed a swelling ratio of 69.44 g/g, biodegradation rate of 23.9%, and compressive strength of 1.074 MPa. Thus, it can be concluded that the new designed biodegradable P(NIPAAm) hydrogels can be promising materials as nitrate fertilizer reservoirs and also for controlled fertilizer release in soil media for agricultural applications.
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Stealey, Samuel T., Akhilesh K. Gaharwar, and Silviya Petrova Zustiak. "Laponite-Based Nanocomposite Hydrogels for Drug Delivery Applications." Pharmaceuticals 16, no. 6 (May 31, 2023): 821. http://dx.doi.org/10.3390/ph16060821.
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Hydrogels are widely used for therapeutic delivery applications due to their biocompatibility, biodegradability, and ability to control release kinetics by tuning swelling and mechanical properties. However, their clinical utility is hampered by unfavorable pharmacokinetic properties, including high initial burst release and difficulty in achieving prolonged release, especially for small molecules (<500 Da). The incorporation of nanomaterials within hydrogels has emerged as viable option as a method to trap therapeutics within the hydrogel and sustain release kinetics. Specifically, two-dimensional nanosilicate particles offer a plethora of beneficial characteristics, including dually charged surfaces, degradability, and enhanced mechanical properties within hydrogels. The nanosilicate–hydrogel composite system offers benefits not obtainable by just one component, highlighting the need for detail characterization of these nanocomposite hydrogels. This review focuses on Laponite, a disc-shaped nanosilicate with diameter of 30 nm and thickness of 1 nm. The benefits of using Laponite within hydrogels are explored, as well as examples of Laponite–hydrogel composites currently being investigated for their ability to prolong the release of small molecules and macromolecules such as proteins. Future work will further characterize the interplay between nanosilicates, hydrogel polymer, and encapsulated therapeutics, and how each of these components affect release kinetics and mechanical properties.
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Kobayashi, Mako, Junpei Kadota, Yoshihide Hashimoto, Toshiya Fujisato, Naoko Nakamura, Tsuyoshi Kimura, and Akio Kishida. "Elastic Modulus of ECM Hydrogels Derived from Decellularized Tissue Affects Capillary Network Formation in Endothelial Cells." International Journal of Molecular Sciences 21, no. 17 (August 31, 2020): 6304. http://dx.doi.org/10.3390/ijms21176304.
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Recent applications of decellularized tissue have included the use of hydrogels for injectable materials and three-dimensional (3D) bioprinting bioink for tissue regeneration. Microvascular formation is required for the delivery of oxygen and nutrients to support cell growth and regeneration in tissues and organs. The aim of the present study was to evaluate the formation of capillary networks in decellularized extracellular matrix (d-ECM) hydrogels. The d-ECM hydrogels were obtained from the small intestine submucosa (SIS) and the urinary bladder matrix (UBM) after decellularizing with sodium deoxycholate (SDC) and high hydrostatic pressure (HHP). The SDC d-ECM hydrogel gradually gelated, while the HHP d-ECM hydrogel immediately gelated. All d-ECM hydrogels had low matrix stiffness compared to that of the collagen hydrogel, according to a compression test. D-ECM hydrogels with various elastic moduli were obtained, irrespective of the decellularization method or tissue source. Microvascular-derived endothelial cells were seeded on d-ECM hydrogels. Few cells attached to the SDC d-ECM hydrogel with no network formation, while on the HHP d-ECM hydrogel, a capillary network structure formed between elongated cells. Long, branched networks formed on d-ECM hydrogels with lower matrix stiffness. This suggests that the capillary network structure that forms on d-ECM hydrogels is closely related to the matrix stiffness of the hydrogel.
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Tavakoli, Shima, and Agnes S. Klar. "Advanced Hydrogels as Wound Dressings." Biomolecules 10, no. 8 (August 11, 2020): 1169. http://dx.doi.org/10.3390/biom10081169.
Full textAbstract:
Skin is the largest organ of the human body, protecting it against the external environment. Despite high self-regeneration potential, severe skin defects will not heal spontaneously and need to be covered by skin substitutes. Tremendous progress has been made in the field of skin tissue engineering, in recent years, to develop new skin substitutes. Among them, hydrogels are one of the candidates with most potential to mimic the native skin microenvironment, due to their porous and hydrated molecular structure. They can be applied as a permanent or temporary dressing for different wounds to support the regeneration and healing of the injured epidermis, dermis, or both. Based on the material used for their fabrication, hydrogels can be subdivided into two main groups—natural and synthetic. Moreover, hydrogels can be reinforced by incorporating nanoparticles to obtain “in situ” hybrid hydrogels, showing superior properties and tailored functionality. In addition, different sensors can be embedded in hydrogel wound dressings to provide real-time information about the wound environment. This review focuses on the most recent developments in the field of hydrogel-based skin substitutes for skin replacement. In particular, we discuss the synthesis, fabrication, and biomedical application of novel “smart” hydrogels.
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Mazzarotta, Alessia, Tania Mariastella Caputo, Luca Raiola, Edmondo Battista, Paolo Antonio Netti, and Filippo Causa. "Small Oligonucleotides Detection in Three-Dimensional Polymer Network of DNA-PEG Hydrogels." Gels 7, no. 3 (July 12, 2021): 90. http://dx.doi.org/10.3390/gels7030090.
Full textAbstract:
The control of the three-dimensional (3D) polymer network structure is important for permselective materials when specific biomolecule detection is needed. Here we investigate conditions to obtain a tailored hydrogel network that combines both molecular filtering and molecular capture capabilities for biosensing applications. Along this line, short oligonucleotide detection in a displacement assay is set within PEGDA hydrogels synthetized by UV radical photopolymerization. To provide insights on the molecular filter capability, diffusion studies of several probes (sulforhodamine G and dextrans) with different hydrodynamic radii were carried out using NMR technique. Moreover, fluorometric analyses of hybridization of DNA oligonucleotides inside PEGDA hydrogels shed light on the mechanisms of recognition in 3D, highlighting that mesh size and crowding effect greatly impact the hybridization mechanism on a polymer network. Finally, we found the best probe density and diffusion transport conditions to allow the specific oligonucleotide capture and detection inside PEGDA hydrogels for oligonucleotide detection and the filtering out of higher molecular weight molecules.
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Zhao, Chenjia, Jingyuan Ji, Tianjun Yin, Jing Yang, Yuan Pang, and Wei Sun. "Affinity-Controlled Double-Network Hydrogel Facilitates Long-Term Release of Anti-Human Papillomavirus Protein." Biomedicines 9, no. 10 (September 23, 2021): 1298. http://dx.doi.org/10.3390/biomedicines9101298.
Full textAbstract:
Hydrogels have recently received attention as delivery carriers owing to their good biocompatibility and structural similarity to natural extracellular matrices. However, the utilization of traditional single-network (SN) hydrogels is limited by poor mechanical properties and burst drug release. Therefore, we developed a novel double-network (DN) hydrogel, which employs an alginate (ALG)/polyethylene glycol diacrylate (PEGDA) network to adjust the mechanical strength and a positively charged monomer AETAC (2-(acryloyloxy)ethyl]trimethyl-ammonium chloride) to regulate the release curve of the electronegative anti-human papillomavirus (HPV) protein (bovine β-lactoglobulin modified with 3-hydroxyphthalic anhydride) based on an affinity-controlled delivery mechanism. The results show that the double-network hydrogel strongly inhibits the burst release, and the burst release amount is about one-third of that of the single-network hydrogel. By changing the concentration of the photoinitiator, the mechanical strength of the DN hydrogels can be adjusted to meet the stiffness requirements for various tissues within the range of 0.71 kPa to 10.30 kPa. Compared with the SN hydrogels, the DN hydrogels exhibit almost twice the mechanical strength and have smaller micropores. Cytotoxicity tests indicated that these SN and DN hydrogels were not cytotoxic with the result of over 100% relative proliferation rate of the HUVECs. Furthermore, DN hydrogels can significantly alleviate the burst release of antiviral proteins and prolong the release time to more than 14 days. Finally, we utilized digital light processing (DLP) technology to verify the printability of the DN hydrogel. Our study indicates that ALG/PEGDA-AETAC DN hydrogels could serve as platforms for delivering proteins and show promise for diverse tissue engineering applications.
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Lusina, Aleksandra, and Michał Cegłowski. "Molecularly Imprinted Polymers as State-of-the-Art Drug Carriers in Hydrogel Transdermal Drug Delivery Applications." Polymers 14, no. 3 (February 8, 2022): 640. http://dx.doi.org/10.3390/polym14030640.
Full textAbstract:
Molecularly Imprinted Polymers (MIPs) are polymeric networks capable of recognizing determined analytes. Among other methods, non-covalent imprinting has become the most popular synthesis strategy for Molecular Imprinting Technology (MIT). While MIPs are widely used in various scientific fields, one of their most challenging applications lies within pharmaceutical chemistry, namely in therapeutics or various medical therapies. Many studies focus on using hydrogel MIPs in transdermal drug delivery, as the most valuable feature of hydrogels in their application in drug delivery systems that allow controlled diffusion and amplification of the microscopic events. Hydrogels have many advantages over other imprinting materials, such as milder synthesis conditions at lower temperatures or the increase in the availability of biological templates like DNA, protein, and nucleic acid. Moreover, one of the most desirable controlled drug delivery applications is the development of stimuli-responsive hydrogels that can modulate the release in response to changes in pH, temperature, ionic strength, or others. The most important feature of these systems is that they can be designed to operate within a particular human body area due to the possibility of adapting to well-known environmental conditions. Therefore, molecularly imprinted hydrogels play an important role in the development of modern drug delivery systems.