Strontium-cerium surface functionalization of titanium scaffold: unlocking the potential of element incorporation for bone implant application

This study focused on developing Strontium (Sr) and Cerium (Ce), dual-element incorporated nanonetwork structured titania layered surface over titanium (Ti) metal for enhanced biocompatibility. Here, by utilizing the alkali-mediated surface modification approach, both elements were successfully incorporated into the Ti metal surface, as evidenced by SEM-EDX and further confirmed by XPS and HR-TEM analysis. Improved surface morphology, hydrophilicity, surface roughness, and surface phase formation were also examined using FE-SEM images, WCA measurements, AFM analysis, and laser Raman spectroscopy to verify the role of this surface modification approach in augmenting the surface characteristics. SrCe incorporated surfaces demonstrated antibacterial activity against both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria and were also evaluated for their in vitro cytocompatibility towards MG-63 cells and in vivo osseointegration properties in the rat (Rattus norvegicus) model. Better cell adhesion, cytoskeletal organization, non-cytotoxicity, protein adsorption, mitochondrial membrane potential, and extracellular matrix mineralization of the dual element incorporated surface further favoured the improved bone formation over the modified 3D printed scaffolds compared to the unmodified. In vivo assessments in the rat-tibial-defect model by radiographic, micro-CT imaging, and RT-PCR-based osteogenic marker genes expression profiles further highlighted improved bone regeneration and osseointegration at the modified surface. Thus, the combinatorial effect of surface-incorporated Ce and Sr ions over the Ti could be beneficial in advancing its potential for applications in tissue engineering and regenerative medicine.