Preparation of Thermosensitive Hydroxybutyl Chitosan/Silk Fibroin Hybrid Hydrogels

Endowing silk fibroin (SF) with the thermosensitivity of rapid in situ gelation remains a challenge in the field of silk fibroin-based tissue engineering scaffolds and injectable soft tissue fillers. In this study, thermosensitive hydroxybutyl chitosan (HBC)/SF hybrid hydrogels are prepared by physical interaction between HBC and SF. In HBC/SF hybrid system, hydrophobic segments of HBC are aggregated to form microaggregates at physiological temperature, which induce hydrophobic segments of SF to aggregate to the microaggregates by hydrophobic interaction, thus achieving the sol-gel transformation of the two components jointly. The observations and tests of the gelation process show that HBC/SF hybrids with mass ratios of 95/5, 90/10, 85/15, 80/20, 75/25, and 70/30 can complete sol-gel transition rapidly within 5-8 min at 37 degrees C, and have the reversibility of sol-gel transition. CCK-8 assay results reveal that the cytotoxicity of HBC hydrogel is effectively reduced by the introduction of SF component. Thermosensitive HBC/SF hybrids have the potential to be used as injectable tissue engineering scaffolds and soft tissue filler.