Surface modification of titanium implants with micro–nano-topography and NIR photothermal property for treating bacterial infection and promoting osseointegration

Abstract: A double acid corrosion and subsequent hydrothermal treatment were used to fabricate a micro–nano-structured Ti substrates (Ti–M–N). Afterward, the mesoporous polydopamine (MPDA) nanoparticles as photothermal agent were prepared and immobilized on the surface of Ti–M–N samples, in order to obtain Ti–M–N-MPDA sample. Unique micro–nanostructure properties and the photothermal effect of the modified Ti implant caused physical stress on the bacteria and the bacterial membrane damage, and eventually led to bacteria death. More importantly, based on excellent bioactivity and cytocompatibility of mussel-inspired materials, MPDA promoted adhesion, proliferation and osteogenic differentiation of mesenchymal stem cells in vitro. Furthermore, animal experiments in vivo further confirmed that the modified Ti implants could enhance osseointegration. Graphic abstract: [Figure not available: see fulltext.]