Search

Hyaluronic acid (HA) is made up of repeating disaccharide units (β-1,4-d-glucuronic acid and β-1,3-N-acetyl-d-glucosamine) and is a major constituent of the extracellular matrix. HA and its derivatives which possess excellent biocompatibility and physiochemical properties have been studied in drug delivery and tissue engineering applications. Tyramine-based HA hydrogel with good compatibility to cell and tissue has been reported recently. However, inferior mechanical property may limit the biomedical application of the HA hydrogel. In this study, HA/graphene oxide (GO) nanocomposite (NC) hydrogel was prepared through a horseradish peroxidase catalyzed in situ cross-linking process. As compared with pure HA hydrogels, incorporation of GO to the HA matrix could significantly enhance the mechanical properties (storage moduli 1800 Pa) of the hydrogel and prolong the release of rhodamine B (RB) as the model drug from the hydrogel (33 h) as well. In addition, due to the multiple interactions between GO and RB, the NC hydrogels showed excellent pH-responsive release behavior. The release of RB from the NC hydrogel was prolonged at low pH (pH 4.0) in the presence of GO, which could be attributed to the enhanced interactions between GO and HA as well as with RB. In situ three-dimensional encapsulation of mouse embryonic fibroblasts (BALB 3T3 cells) in the NC hydrogels and cytotoxicity results indicated the cytocompatibility of both the enzymatic cross-linking process and HA/GO NC hydrogels (cell viability 90.6 ± 4.25%). The enzymatically catalyzed fabrication of NC hydrogels proved to be an easy and mild approach, and had great potential in the construction of both tissue engineering scaffolds and stimuli-responsive drug release matrices.

Hyaluronic acid (HA) is made up of repeating disaccharide units (β-1,4-d-glucuronic acid andβ-1,3-N-acetyl-d-glucosamine) and is a major constituent of the extracellular matrix. HA and its derivatives which possess excellent biocompatibility and physiochemical properties have been studied in drug delivery and tissue engineering applications. Tyramine-based HA hydrogel with good compatibility to cell and tissue has been reported recently. However, inferior mechanical property may limit the biomedical application of the HA hydrogel. In this study, HA/graphene oxide (GO) nanocomposite (NC) hydrogel was prepared through a horseradish peroxidase catalyzedin situcross-linking process. As compared with pure HA hydrogels, incorporation of GO to the HA matrix could significantly enhance the mechanical properties (storage moduli 1800 Pa) of the hydrogel and prolong the release of rhodamine B (RB) as the model drug from the hydrogel (33 h) as well. In addition, due to the multiple interactions between GO and RB, the NC hydrogels showed excellent pH-responsive release behavior. The release of RB from the NC hydrogel was prolonged at low pH (pH 4.0) in the presence of GO, which could be attributed to the enhanced interactions between GO and HA as well as with RB.In situthree-dimensional encapsulation of mouse embryonic fibroblasts (BALB 3T3 cells) in the NC hydrogels and cytotoxicity results indicated the cytocompatibility of both the enzymatic cross-linking process and HA/GO NC hydrogels (cell viability 90.6 ± 4.25%). The enzymatically catalyzed fabrication of NC hydrogels proved to be an easy and mild approach, and had great potential in the construction of both tissue engineering scaffolds and stimuli-responsive drug release matrices. [ABSTRACT FROM AUTHOR]

Abstract: Hyaluronan (HA) and aliphatic oligo-carbonate based biodegradable hydrogels were synthesized via photopolymerization of a methacrylated HA (HA-GMA) with oligo(2,2-dimethyltrimethylene carbonate)-block-poly(ethylene glycol)-block -oligo(2,2-dimethyltrimethylene carbonate) diacrylate (DPD-DA). Hydrogels with tunable physical properties such as swelling behavior, crosslink density, and mesh size were fabricated with different concentrations of HA-GMA or DPD-DA. Hydrogel–bovine serum albumin (BSA) construct was prepared by in situ photopolymerization. BSA release from the construct was evaluated in vitro and the release behavior can be controlled by adjusting the concentration of the precursors. By tailoring the concentration of different precursors in the hydrogels, more sustained release of BSA can be achieved (i.e., 120h). The cytotoxicity of this novel hydrogel was also investigated and the hydrogel proved to be comparably cytocompatible to PEG hydrogels. [Copyright &y& Elsevier]