<i>In vivo</i>drug release and antibacterial properties of vancomycin loaded hydroxyapatite/chitosan composite

The present study was designed to investigate the in vivo drug release and antibacterial properties of a novel mesoporous hydroxyapatite/chitosan (mesoHA-CS) composite loaded with vancomycin (VCM). VCM-mesoHA/CS composite was prepared via a freeze-drying method. The successful loading of VCM in the composite scaffold was verified by FT IR analyses. SEM observation revealed the mesoporous structure of the VCM-mesoHA/CS composite with the pore size of 50-100 µm. Medicated composites were then implanted into the muscular pockets of extremity in rabbits. The results demonstrated that local VCM concentration in muscle tissue could maintain higher than the minimum inhibitory concentration at the site of implantation for long time (i.e. 4 weeks). As a result, the number of viable methicillin-resistant Staphylococcus aureus (MRSA) on mesoHA/CS could be significantly suppressed after the VCM-mesoHA/CS implantation. These results indicated that the mesoHA/CS composite may be promising scaffold as drug storage and release vehicle applied for local antibacterial drug release and bone repair.