Dual-Functional Nano-Functionalized Titanium Scaffolds to Inhibit Bacterial Growth and Enhance Osteointegration

Implantable biomaterials play a key role for the success of orthopedic surgery procedures. However, infections remain one of the most damaging post-operative complications that lead to the implant failure. Recently, several approaches have been proposed to avoid or manage implant-associated infections. Among these, an appropriate surface functionalization to confer intrinsic antibacterial properties preserving the osteo-integration ability represents an appealing strategy for the development of innovative implant materials. Titanium and its alloys are the most used materials for manufacturing of both articular and bone skull prostheses as well as dental implants. However, to date there is still a significant clinical need to improve their bioactivity, osseointegration and antibacterial activity. In this study, titanium biomimetic scaffolds are prepared by nano-functionalization with TiO₂ (Ti_TiO₂) and γFe₂O₃ (Ti_γFe₂O₃). Both cytocompatibility and antibacterial activity have been evaluated. Data show that both nano-functionalized scaffolds exhibit a good antibacterial activity towards Staphylococcus aureus, reducing colony number to 99.4% (Ti_TiO₂) and 99.9% (Ti_γFe₂O₃), respectively. In addition, an increase of both human adipose-derived mesenchymal stem cells (hADSCs) cell proliferation (up to 4.3-fold for Ti_TiO₂ and 3.7-fold for Ti_γFe₂O₃) and differentiation has been observed. These data suggest that these nano-functionalized titanium substrates represent promising prototypes for new antimicrobial and osteoconductive biomaterials to be used in the orthopedic field to reconstruct significant bone defect.