Engineered Titanium Surfaces with Electrophoretically Deposited Graphene Oxide-Mesoporous Bioglass Nanocoatings for Enhanced Bone Regeneration and Antibacterial Activity

Abstract

Multifunctional surface engineering of titanium implants that integrates osteogenic activity with localized antibacterial function is highly desirable yet remains challenging. Here, we report a nanostructured graphene oxide/mesoporous bioactive glass nanoparticle (GO/MBGN) nanocoating fabricated via electrophoretic deposition (EDP) using a chitosan-assisted strategy. An amine-functionalized mesoporous bioactive glass nanoparticle (MBGN-NH₂) enables co-deposition with negatively charged GO, resulting in uniform and stable coatings with tunable nanotopography and composition. Structural and microscopic analyses confirm homogeneous incorporation of MBGN within the GO matrix while preserving the amorphous mesoporous structure, essential for ion release and drug loading. The GO/MBGN nanocoatings significantly enhance cellular responses in a composition-dependent manner. Notably, GO-10MBGN promotes improved cell spreading, focal adhesion, and proliferation of rat bone marrow-derived mesenchymal stem cells. Osteogenic differentiation is markedly upregulated, as evidenced by increased expression of alkaline phosphatase (ALP), collagen type I (COL I), and osteocalcin (OCN), attributed to combined effects of nanoscale surface features and sustained release of Ca²⁺ and SiO₄^4– ions. Furthermore, gentamicin sulfate (GENT)-loaded MBGN endow controlled drug release, exhibiting an initial burst followed by sustained delivery over 6 weeks. This results in effective antibacterial activity against Staphylococcus aureus, with enhanced inhibition observed for higher MBGN content. Collectively, this work establishes that GO/MBGN nanocoatings possess both osteoinductive and antibacterial functionalities, offering a promising strategy for advanced titanium implants.