Effects of hydroxybutyl chitosan on improving immunocompetence and antibacterial activities.

Chitosan (CS) has been reported to have utility for various potential applications in biomedicine, tissue engineering, and cosmetics, as well as in the formulation of antibacterial agents because it exhibits a variety of desirable attributes, including low-toxicity, biodegradability, excellent biocompatibility, and broad-spectrum antibacterial activity. However, the full realization of CS's biomedical applications are practically constrained by its poor solubility. The goal of the present study is to prepare hydroxybutyl chitosan (HBCS) and investigate its impacts on immunocompetence, and its antibacterial activity. In the current study, HBCS was synthesized by modifying the hydroxybutyl group on the chitosan molecule using an etherification method. The physicochemical properties of the synthesized HBCS were characterized by various methods. Results showed that hydro-soluble HBCS exhibited excellent hygroscopicity and moisture retention. It was also found that HBCS exhibited notable cytocompatibility when cultured with mouse embryo fibroblasts. HBCS was able regulate immuno-functionality and promote immunocompetence by improving phagocytosis of macrophages and reinforcing lymphocyte activity in vivo and in vitro. Moreover, HBCS was also found to inhibit L-929 cell migration, indicating the impeded migration and metastasis behaviors of fibrosarcoma cells. Additionally, HBCS displayed favorable antimicrobial functionality against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. This study demonstrated that HBCS could in turn lock moisture, can promote immunocompetence activity, can inhibit fibrosarcoma cell migration, and exhibits anti-bacterial functionality. Taken together, these results indicate that HBCS shows substantial promise for applications in cosmetics, biomedicine, and antibacterial therapies.