Gentamicin sulfate attachment and release from anodized Ti-6A1-4V orthopedic materials

A novel method has been developed to attach, retain, and release antibiotics from titanium based materials. This technique consists of forming porous surface coatings by anodizing and using the surface chemical properties of the oxide coatings to attach antibiotics. Coatings with pores in the size range 0.1-0.5 micron have been formed in acid solutions. The attachment and retainment of gentamicin sulfate, a cationic antibiotic, to the coatings has been investigated using microbiological methods. In vitro test results have shown that the duration of antimicrobial activity on the surface of anodized materials is dependent on the porosity and isoelectric point of the coatings. Using microporous oxide coatings formed in phosphoric acid solutions, it has been found that antimicrobial activity could be retained for more than 2 weeks.