Osteoconductive, Osteogenic, and Antipathogenic Plasma Electrolytic Oxidation Coatings on Titanium Implants with BMP-2.

We report a one-pot plasma electrolytic oxidation (PEO) strategy for forming a multi-element oxide layer on the titanium surface using complex electrolytes containing Na 2 HPO 4 , Ca(OH) 2 , (NH 2 ) 2 CO, Na 2 SiO 3 , CuSO 4 , and KOH compounds. For even better bone implant ingrowth, PEO coatings were additionally loaded with bone morphogenetic protein-2 (BMP-2). The samples were tested in vivo in a mouse craniotomy model. Tests for bactericidal and fungicidal activity were carried out using clinically isolated multi-drug-resistant Escherichia coli ( E. coli ) K261, E. coli U20, methicillin-resistant Staphylococcus aureus ( S. aureus ) CSA154 bacterial strains, and Neurospora crassa ( N. crassa ) and Candida albicans ( C. albicans ) D2528/20 fungi. The PEO-Cu coating effectively inactivated both Gram-positive and Gram-negative bacteria at low concentrations of Cu 2+ ions: minimal bactericidal concentration for E. coli and N. crassa (99.9999%) and minimal inhibitory concentration (99.0%) for S. aureus were 5 ppm. For all studied bacterial and fungal strains, PEO-Cu coating completely prevented the formation of bacterial and fungal biofilms. PEO and PEO-Cu coatings demonstrated bone remodeling and moderate osteoconductivity in vivo , while BMP-2 significantly enhanced osteoconduction and osteogenesis. The obtained results are encouraging and indicate that Ti-based materials with PEO coatings loaded with BMP-2 can be widely used in customized medicine as implants for orthopedics and cranio-maxillofacial surgery.