Antibiotic-eluting bioresorbable composite fibers for wound healing applications: Microstructure, drug delivery and mechanical properties

Novel antibiotic-eluting composite fibers designed for use as basic wound dressing elements were developed and studied. These structures were composed of a polyglyconate core and a porous poly(dl-lactic-co-glycolic acid) shell loaded with one of three antibiotic drugs: mafenide acetate, gentamicin sulphate and ceftazidime pentahydrate. The shell was prepared by the freeze-drying of inverted emulsions. The fiber investigation focused on the effects of the emulsion's formulation on the shell microstructure and on the resulting profile of drug release from the fibers. Albumin was found to be the most effective surfactant for stabilizing the inverted emulsions and also to have a beneficial holdup effect on the release kinetics of the hydrophilic antibiotic drugs, especially mafenide acetate, probably through a specific interaction. An increase in the organic:aqueous phase ratio, polymer content or molecular weight of the host polymer resulted in a decrease in the burst release and a more moderate release profile due to changes in shell microstructure. The first two parameters were found to be more effective than the third. The diverse release profiles obtained in the current study and the good mechanical properties indicate that our new composite fibers have good potential for use in wound healing applications.