Antimicrobial hydroxyapatite reinforced-polyelectrolyte complex nanofibers with long-term controlled release activity for potential wound dressing application

The prevention of wound infection has remained to be a critical step for facilitating wound healing following the application of wound dressing. To overcome such challenge, nano-hydroxyapatite (n-HAP) with high specific surface area, excellent biocompatibility, high mechanical strength and strong adsorption capacity was developed into a novel controlled release system for antimicrobial therapy. In general, n-HAP was loaded with a model antibiotic, tetracycline hydrochloride and was subsequently encapsulated inside chitosan/gelatin polyelectrolyte complex (PEC) nanofibers with a typical core-shell geometry. Firstly, the encapsulation of either tetracycline hydrochloride (TCH) or n-HAP led to the slight shrinkage of fiber diameter and enhancement in the thermotropic stability of PEC nanofiber. Secondly, the good water retention and air transmission properties of PEC was not impaired by the inclusion of n-HAP and TCH. Finally, the n-HAP reinforced PEC nanofiber membrane with encapsulated tetracycline hydrochloride has achieved the effect of long-term drug release, thereby improving the antibacterial efficacy against S. aureus , a common pathogen. Based on the good water retention, high rigidity, long term sustained drug release and prolonged antibacterial therapeutic efficacy, n-HAP reinforced PEC nanofiber membranes will serve as a promising platform for developing into novel antimicrobial wound dressings.