Urethanes PDMS-based: Functional hybrid coatings for metallic dental implants

In this study, we propose new polymeric coatings for metallic implants that impart biocompatibility and antibacterial features to such surfaces. The starting material, poly(cyclic carbonate)-polydimethylsiloxane, was prepared from carbon dioxide fixation and then sequentially reacted by aminolysis with an organoaminosilane, affording the formation of an urethanic polydimethylsiloxane-based material. Finally, a hybrid coating was obtained by performing a sol-gel process on the metallic surfaces, catalyzed by phosphotungstic acid. We provide evidence that due to the polydimethylsiloxane segments governing the surface termination, the hybrid coatings show a hydrophobic character. Furthermore, due the presence of phosphotungstic acid in the upper surface, the adhesion of Gram-positive and Gram-negative bacteria is suppressed in 4 h of contact with aqueous bacterial cultures. In addition, the coatings presented a > 70% cytocompatibility besides a low cytotoxicity, making them interesting candidates as biocompatible materials and an alternative to avoiding the biofilm associated with bacterial infections.