Formulation and in vitro characterization of a composite biodegradable scaffold as antibiotic delivery system and regenerative device for bone

A biodegradable composite scaffold, useful as tridimensional bone regenerative scaffold (3D) and antibiotic delivery system (DDs), is here formulated and characterized. The device, called as 3D-DDS, is an injectable or moldable scaffold based on chitosan chloride crosslinked with glycerol 2-phosphate disodium salt and laden with bovine bone substitute (BBs) granules and gentamicin loaded polylactide-coglycolide-co-poly ethilenglycol (PLGA-PEG) microparticles. 3D-DDS characterization results show that microparticles are homogeneously distributed in the composite matrix, and do not interfere with scaffold stability. The lyophilized 3D-DDS has high rehydration ability and is able to restrain physically bovine bone granules and microparticles up to 45 days in in vitro simulated conditions. Bactericidal action is high in the first 4 h and it accounts for superimposable effect of gentamicin release and bacteriostatic chitosan properties; sustained gentamicin bactericidal effect is evident up to 14 days.