CONICET | Buscador de Institutos y Recursos Humanos

Metals are used in several orthopedic applications as fixation elements for the stabilization of fractures or as prostheses. One of the most common orthopedic bio materials in many developing countries is surgical grade stainless steel (SS). However, its use as permanent implant in orthopaedic surgery is conditioned due to its limited corrosion resistance, osseointegration and absence of antibacterial effect. The aim of this work is to generate a degradable coating with antibacterial properties for stainless steel to be used in implantable medical devices. The coating is composed of a biopolymer/silica-gentamicin nanoparticle composite obtained by electrophoretic deposition (EPD) on surgical grade stainless steel plates. The coating surface was characterized by microscopic examination and in vitro performance was evaluated after immersion in phosphate buffered saline (PBS) solution, simulated body fluid (SBF) and cell medium, to analyse coating degradation, antibiotics release, cell attachment (ST-2 stromal cells) and antibacterial (Escherichia coli and Staphylococcus aureus) properties. EPD coatings were uniform and copy the surface of the SS substrate. Also the distribution of silica-gentamicin nanoparticles was homogeneous in all of the coated area. The degradation of the chitosan-gelatin coatings was evident after 7 days of immersion. The gentamicin release showed excellent antibacterial behavior at 24h meanwhile the cell proliferation at 7 days was not inhibited. The results show that the coating system presents a promising behavior to prevent hospital infections at early implantation times.