Preparation of a recombinant collagen-peptide (RHC)-conjugated chitosan thermosensitive hydrogel for wound healing.

Thermosensitive chitosan hydrogels have been widely used in drug delivery and tissue repair, but further applications of these hydrogels have been limited by their weak mechanical strength and poor bioactivity. A thermoresponsive hydrogel formed by conjugating recombinant human collagen-peptide (RHC) with chitosan might be better suited for cell encapsulation and wound repair. RHC-chitosan hydrogels were prepared and tested, and the results showed that moderate RHC conjugation led to hydrogels with lower gelation temperature. The prepared RHC-containing hydrogels showed superior mechanical strength to chitosan-only hydrogels. Additionally, cells exhibited superior viability when cultured with RHC-modified hydrogels compared with hydrogels that had not been conjugated with RHC. Finally, RHC-chitosan hydrogels were injected onto the backs of rats with second-degree burns and promoted cell infiltration, vessel formation, and wound healing. Overall, the use of RHC-chitosan hydrogels is a promising and effective therapeutic approach for burn wound treatment.

Electrospinning of in situ crosslinked recombinant human collagen peptide/chitosan nanofibers for wound healing.

Electrospun collagen nanofibers are effective for wound healing; however, many problems, such as the tedious preparation process, weak strength and poor structure integration, limit further applications. In this study, recombinant human collagen (RHC) peptides and a simple one-step crosslinking strategy were used to prepare RHC/chitosan nanofibers. With the nonpathogenic, water-soluble RHC and a mild electrospinning solvent, in situ crosslinked nanofibers (S-CN) not only simplified the preparation procedure but also maintained a more integrated morphology. Compared with the immersed crosslinked nanofibers (I-CN), S-CN showed better performance in moisture retention, degradation and mechanical strength tests. In vitro cell proliferation, morphology and RT-PCR studies confirmed that fibroblasts presented better activities on nanofibers crosslinked in situ. Importantly, after treating with the nanofibers, rapid epidermidalization and angiogenesis were observed in an SD rat scalding model. All these data suggest that electrospun RHC/chitosan nanofibers crosslinked in situ are an ideal candidate that can be used for wound healing applications.