Prolongation of bactericidal efficiency of chitosan — Bioactive glass coating by drug controlled release

Multifunctional bone implant coatings are developing for promoting osseointegration and bactericidal efficiency, simultaneously. In present study, chitosan/bioactive glass nanoparticles/vancomycin composite was coated on hydrothermally etched titanium substrate by drop casting method. For prolongation of antibacterial activity during long term, vancomycin was immobilized on bioactive glass nanoparticles, then the modified nanoparticles were deposited with chitosan on hydrothermally etched titanium. SEM, EDS, FT-IR and wettability test were used for materials characterization. The immobilization of vancomycin onto bioactive glass nanoparticles was proved by FT-IR. Release of vancomycin was measured by UV-spectroscopy for up to 14 days. Antibacterial performance against Methicillin Resistance Staphylococcus Aureus (MRSA) strain, both planktonic and in biofilm, was evaluated for up to 14 days. Conjugation of vancomycin revealed a prolonged release profile and bactericidal activity compared to coating without conjugation of the drug. In vitro, coatings with immobilized vancmycin completely eliminated, or reduced the number of planktonic and adherent MRSA by up to 4 and 2 orders of magnitude in initial and later stages, respectively. Vancomycin burst release made a delay in ALP enzyme secretion from MC3T3 cells, while in coating with immobilized vancomycin, the burst release decreased and consequently the delay in ALP enzyme secretion disappeared. The release profile of conjugated vancomycin fitted with Korsmeyer-Peppas model.