Multifunctional sericin/graphene oxide coating on titanium with antibacterial activity and cytocompatibility

The increasing incidence of bone fractures highlights the urgent need for advanced implant materials. Despite its extensive use, the performance of Ti-6Al-4V implants is often compromised by bacterial infections that hinder osseointegration and long-term stability. In this study, a sericin-based coating was fabricated on Ti-6Al-4V via a layer-by-layer assembly using tannic acid (TA) as a linker and sericin/graphene oxide (GO) as a top layer to enhance antibacterial and bioactive properties. The formation of the TA/sericin/GO multilayered coating was confirmed by scanning electron microscopy, X-ray photoelectron spectroscopy, and water contact angle analyses. The sericin-modified surfaces exhibited enhanced bioactivity, promoting calcium phosphate deposition with a bone-like Ca/P ratio after 14 days in simulated body fluid. Antibacterial evaluation against Staphylococcus aureus showed bacterial reductions of 84.45% and 89.94% for Ti–TA–SS and Ti–TA–SS–GO, respectively. The coatings maintained antibacterial activity after 14 days of immersion, indicating good stability and strong potential for long-term performance under physiological conditions.