Drug-release dynamics and antibacterial activities of chitosan/cefazolin coatings on Ti implants

Abstract Chitosan/drug (cefazolin) coatings were synthesized on alkali-treated Ti surfaces via electrophoretic deposition to improve the antibacterial activities and corrosion resistances of the surfaces. The coatings exhibited desirable adhesion to the alkali-treated Ti due to the penetration of chitosan and drug into the pores of the substrates. The chitosan were cationic molecules which carried drug and both of them migrated toward the cathode during electrophoretic deposition. At a low potential, the drug dissolved in the chitosan film, whereas at a high potential, the drug aggregated into sheets on the surface of chitosan. The high potential provided the coating with high drug loading and releasing capacity. The total drug release of chitosan/drug coatings with 4.3 and 6.9 μm thickness in Hank's balanced salt solution (HBSS) was about 3 and more than 14 days, respectively. The coatings exhibited increased corrosion resistance than the Ti in HBSS evaluated via potentiostat. Additionally, the coating with high drug loading demonstrated approximate 100% antibacterial activities against Escherichia coli; thus, the proposed coatings can be used as promising Ti coatings to limit bacterial adhesion and proliferation.