PH-triggered drug release of ciprofloxacin from layer-by-layer coatings on titanium

Abstract Implant-associated infections are still a major issue in implant surgery. Biofilms tend to form on implant surfaces, like titanium, and can hardly be reached by the immune system. Additionally, systemic treatments with antibiotics often fail and cause severe side effects for the patient. Direct delivery of the antibiotic from the implant surface to the surrounding tissue is one approach to solve this problem. To realize this, the application of pH-sensitive coatings on implant surfaces, which release their cargo only if an infection arises, is a promising option. This can be triggered by the decrease of the pH value occurring in infected tissue. For such pH-sensitive systems with integrated drug loading capacity layer-by-layer coatings with weak polyelectrolytes can be used. Here, we present a coating applied on titanium substrates by dip-coating. As negatively charged polyelectrolyte polyacrylic acid, as positively charged poly(allylamine hydrochloride) is used. As an effective drug, the antibiotic ciprofloxacin is incorporated into the coating and the release profiles are recorded.