Antibacterial properties and biocompatibility of coated titanium substrates

LAURA E. VALENTI; LAURA V. BONNET; MAURICIO R. GALIANO; CARLA E. GIACOMELLI

Buenos Aires

Congreso; Reunión conjunta de Sociedades de Biociencias; 2017

Titanium and titanium alloys have excellent mechanical strength, goodcorrosion resistance and biocompatibility and they have been widely used forproducing orthopedic implants. Osteointegration is a critical response to thelong-term success of these implants. Focusing the attention on the surface ofthe biomaterials, a hydroxiapatite (HA) coating on the implant surface canimprove a direct implant fixation to bone. Even when the interaction ofbiomaterials with living tissues is favored, the problems of bacterial infections persist. A possible solution involves the surface modification with an antibacterial coating which maintains good biocompatibility. Incorporating silver nanoparticles (Ag-NPs) into a HA coating is an effective method to impartsimultaneously both properties to the surface of the biomaterial. The objectiveof this work is to evaluate the antibacterial properties and biocompatibility ofTi6Al4V coated with Ag-NP and HA.To prepare the coatings, a two steps strategy was optimized involving theelectrodeposition of HA and the impregnation with Ag-NP. Coated Ti6Al4Vsubstrates were characterized by spectroscopy and microscopy. For theantimicrobial activity assays, the substrates were incubated with a S. aureusculture and observed by confocal fluorescence spectroscopy, while the viablebacteria were quantified by serial dilution plates. The biocompatibility wasevaluated directly, by culturing human osteosarcoma cells (U-2OS) on thecoated substrates and indirectly, by studying the effect of the extract from thecoated material on the cell culture. The cell viability was quantified by resazurinassay. HA/Ag-NP coating inhibits completely the bacterial adhesion anddiminishes three logs units the number of viable planktonic bacteria with aminimum cytotoxic effect. Therefore, the HA/Ag-NP coating is very promising todevelop more effective orthopedic implants exhibiting antibacterial propertieswithout a detriment in the biocompatibility.