Development, characterization and biological studies of Mn-doped ZnO/Ti biomaterials for regenerative medicine

Bone disease diseases massively affect the world population, with more than two million of surgeries performed worldwide every year. Bone has limited capability to repair very large defects and the use of engineered biomaterials isa mandatory but some clinical issues are observed like rejection and possible infections. Therefore, the development of new biomaterials promoting bone tissue repair and prevent post-surgery infections represents one of the main challenge in regenerative medicine. Titanium is the most used material for implants but it not free from infections. Therefore the modification of Ti surface could represent a valuable strategy to improve both antibacterial and osteo-inductive properties. In this work, we developed a Mn-doped ZnO/Ti biomaterial and evaluated its ability to prevent infections, preserving the osteo-integration. Results indicate that the biomaterial is very effective in antibacterial activity with a bacterial reduction of more than 80% in the case of Staphylococcus aureus, and of 44.4% and 53.6% in the case of Pseudomonas aeruginosa, while maintaining both biocompatibility and the ability to promote osteogenic differentiation, as confirmed by upregulation of key genes (ALP, IBSP, SPARC) in human osteoblasts. This paves the way for a new class of biomaterials for regenerative medicine applications.