In Vitro and In Vivo Evaluation of Tetracycline Loaded Chitosan-Gelatin Nanosphere Coatings for Titanium Surface Functionalization.

Owing to the biocompatibility of titanium surface, titanium implants are suitable substrates for microbial colonization and biofilm formation, which is still a serious clinical threat. Current research trends have been focused on the development of antibacterial coatings on titanium substrate or adhesion resistant surface. In our previous study, tetracycline (Tc) loaded chitosan-gelatin (CSG) nanosphere coatings are successfully fabricated on titanium substrates via electrophoretic deposition. These coatings show nanosphere structure, and excellent antibacterial property in vitro. However, further in vitro and in vivo evaluation of the coatings is required for the future application. Therefore, in the present study, the authors investigate the coatings' mechanical, swelling and degradation property, in vitro cellular response to preosteoblast cells, and the antibacterial property in rabbits. Results show that Tc incorporation can improve the tensile bond strength of the coating, decrease the swelling ratio, and accelerate the degradation of the coating. Although high Tc concentration group exhibits cytotoxicity to MC3T3-E1 cells, its in vivo antibacterial property is preferred, and shows better outcome than the prophylactic administration of Tc. Tc loaded CSG nanosphere coatings are suitable antibacterial coatings for titanium surface functionalization.