Injectable hydrogels based on silk fibroin peptide grafted hydroxypropyl chitosan and oxidized microcrystalline cellulose for scarless wound healing

Scars are consequences of the wound healing process, and eliminating scar formation remains a significant challenge. Here, an injectable HMSC hydrogel was developed based on silk fibroin peptide grafted hydroxypropyl chitosan (HPCS-g-SFP) and oxidized microcrystalline cellulose (OMCC) via Schiff base bonds. The synthesized HPCS-g-SFP copolymer displayed efficient free radical scavenging ability on hydrogen hydroxyl radicals and 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH). The pore size, gelling time, equilibrium swelling rate and water retention properties of HMSC hydrogel could be regulated by changing ratio of OMCC and HPCS-g-SFP. Then, tetramethylpyrazine (TMP) was encapsulated into HMSC hydrogel to obtain TMP-loaded HMSC hydrogel. The TMP-loaded HMSC hydrogel facilitated 95% cell activity retention after culturing with human skin fibroblasts (HSF) or human hypertrophic scar fibroblast (HSFB) cells for 24 h. Additionally, in vivo animal experiments confirmed that TMP-loaded HMSC hydrogel promoted rapid wound healing while preventing scar formation. The designed injectable TMP-loaded HMSC hydrogel has potentials in promoting scarless wound healing. [Display omitted]