Simple UV-Grafting of PolyAcrylic and PolyMethacrylic Acid on Silicone Breast Implant Surfaces: Chemical and Mechanical Characterizations

Poly(dimethyl siloxane) (PDMS) is one of the most widely used materials in the biomedical field. Despite its numerous advantages, its hydrophobic character promotes bacterial adhesion and biofilm formation. For breast implants, biocompatibility is challenged due to the biofilm formed around the implant that can degenerate to severe capsular contracture over time. Thus, the laboratory has set up strategies to prevent bacterial contamination by grafting covalently hydrophilic bioactive polymers on the surface of implants. In this study, poly(methacrylic acid) (PMAc) and poly(acrylic acid) (PAAc) were chosen as non-toxic and biocompatible bioactive polymers known for reducing bacteria adhesion. These polymers are also good candidates to lend reactivity on the surface for further functionalization. X-ray photoelectron Spectroscopy (XPS) and Fourier-Transform Infrared spectroscopy (FTIR) analysis have highlighted the covalent grafting of these polymers. Apparent water contact angle measurements have shown the change in hydrophilicity on the surface, and a colorimetric assay allowed us to assess the grafting rate of PMAc and PAAc. Tensile strength assays were performed to ensure that the functionalization process does not significantly alter the material's mechanical properties. Analyses of the surface aspect and roughness by Scanning Electron Microscope (SEM) and optical profilometer allow us to formulate hypotheses to approach the understanding of the behavior of the polymer once grafted.