Fabrication of novel cross-linker-free chitosan/strontium bioglass composite for wound healing application

Next-generation cross-linker-free Chitosan (CS) and mesoporous strontium bioglass (SrBG) composites were fabricated [CS/nSrBG (n = 1, 2, 3 wt%)] by freeze-drying. Spectroscopic analyses confirmed the interaction of SrBG ions with amino groups of CS which act as the self-cross linker owing to the chelate effect. Thermal analysis revealed a significant increment in the glass transition temperature of composites (150 °C). The CS nanospheres (10-30 nm) deposited on 1SrBG, result in the formation of flake-like morphology. The swelling behavior of the CS/1SrBG enhanced by 200 % compared to SrBG due to the strong interaction of Ca and Sr ions of CS/SrBG. The drug encapsulation efficiency (22 %), loading efficiency (38 %), and controlled drug release (18 %) are improved compared to the pure CS. The cell viability and proliferation of the composites were significantly enhanced by the incorporation of SrBG into chitosan (CS/3SrBG) confirming their non-toxicity to fibroblast cells. The in vitro scratch test showed better cell migration of fibroblast cells. The in vivo wound healing assay towards zebra fish showed thickened epithelium formation. The overall results indicate that the freeze-dried CS/SrBG developed without a cross-linker is a promising candidate for biomedical applications. Further, paves a path towards the development of cross-linker-free bioglass composites.