Additively Manufactured SiO₂ and Cu-Added Ti Implants for Synergistic Enhancement of Bone Formation and Antibacterial...

Commercially pure titanium (CpTi), a bioinert metal, is used as an implant material at low load-bearing sites and as a porous coating on Ti6Al4V at high load-bearing sites. There is an unmet need for metallic biomaterials to improve osseointegration and inherent antimicrobial resistance. In this study, we have added 1 wt % SiO₂ and 3 wt % Cu to the CpTi matrix and processed via metal additive manufacturing (AM). Si⁴⁺ ions promote angiogenesis and osteogenesis. CpTi-SiO₂ composition exhibited 4.5 times higher bone formation at the bone-implant interface over CpTi in an in vivo study with a rat distal femur model. In vitro bacterial studies with Gram-positive Staphylococcus aureus bacterium revealed 85% antibacterial efficacy by CpTi-SiO₂-3Cu than CpTi. CpTi-SiO₂-3Cu did not show any inflammatory markers in vivo, indicating the absence of cytotoxicity, but displayed delayed osseointegration compared to CpTi-SiO₂. CpTi-SiO₂-3Cu displayed 3-fold higher mineralized bone formation than CpTi. Our results emphasize the synergistic effect of SiO₂ and Cu addition in CpTi, promoting enhanced early stage osseointegration and inherent antibacterial efficacy, contributing toward implant longevity and stability in vivo.