Hybrid nanocomposite coatings from PEDOT and BN-TiO₂ nanosheets: Enhanced invitro corrosion resistance, wettability and biocompatibility for biomedical applications

The aim of this study is to develop the polymer nanocomposite coatings based on conducting polymer and hexagonal boron nitride (BN) nanosheets to improve invitro corrosion resistance and biocompatibility of 316L stainless steel (SS) implants. To achieve the highly dispersible BN, the surface of BN was decorated with TiO₂ nanoparticles (~25 nm) and then, the resultant BN-TiO₂ nanosheets was incorporated into poly (3,4-ethylene dioxythiophene) (PEDOT) coatings. Surface and structural characterization results validated the formation of nanocomposite coatings with homogeneous distribution of BN-TiO₂ as well the existing interaction between the BN-TiO₂ and PEDOT matrix. Invitro corrosion analysis of coated 316L SS specimens in simulated body fluid corroborated that the value of corrosion current density (0.0248 μA/cm²) was two orders of magnitude with a lower corrosion rate of 1.4694 × 10⁻³ mmpy for PEDOT/BN-TiO₂ nanocomposite coatings compared with the pure PEDOT. Uncoated 316L SS specimen showed water contact angle (WCA) value of 84.50°, whereas PEDOT/BN-TiO₂ coatings displayed WCA value of about 20°, further inferring the positive role of BN-TiO₂ in the PEDOT matrix. Invitro cell culture analysis on MG63 cells validated the enhanced biocompatibility of developed nanocomposite coatings. Among the studied samples, the PEDOT/10BN-TiO₂ nanocomposite coatings demonstrated enhanced wettability, invitro corrosion resistance, and ability to facilitate osteoblast adhesion. The obtained results suggest that the developed nanocomposite coatings on 316L SS implants have the potential for use in orthopedic applications.