Additively Manufactured SiO 2 and Cu-Added Ti Implants for Synergistic Enhancement of Bone Formation and Antibacterial Efficacy.

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 % SiO 2 and 3 wt % Cu to the CpTi matrix and processed via metal additive manufacturing (AM). Si 4+ ions promote angiogenesis and osteogenesis. CpTi-SiO 2 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-SiO 2 -3Cu than CpTi. CpTi-SiO 2 -3Cu did not show any inflammatory markers in vivo , indicating the absence of cytotoxicity, but displayed delayed osseointegration compared to CpTi-SiO 2 . CpTi-SiO 2 -3Cu displayed 3-fold higher mineralized bone formation than CpTi. Our results emphasize the synergistic effect of SiO 2 and Cu addition in CpTi, promoting enhanced early stage osseointegration and inherent antibacterial efficacy, contributing toward implant longevity and stability in vivo .