Core–Shell NiS@SrTiO₃ Nanorods on Titanium for Enhanced Osseointegration via Programmed Regulation of Bacterial Infection, Angiogenesis, and Osteogenesis

Abstract

Developing bone implants with dynamic self-adjustment of antibacterial, angiogenic, and osteogenic functions in line with a bone regenerative cascade is highly required in orthopedics. Herein, a unique core–shell nanorods array featuring a thin layer of NiS coated on each SrTiO3 nanorod (NiS@SrTiO3) was in situ constructed on titanium (Ti) through a two-step hydrothermal treatment. Under near-infrared (NIR) irradiation, the photoresponsive effect of NiS layer in synergy with the physical perforation of SrTiO3 nanorods initially enabled in vitro antibacterial rates of 96.5% to Escherichia coli and 93.1% to Staphylococcus aureus. With the degradation of the NiS layer, trace amounts of Ni ions were released, which accelerated angiogenesis by upregulating the expression of vascular regeneration-related factors, while the gradual exposure of SrTiO3 nanorods could simultaneously enhance the surface hydrophilicity in favor of cell adhesion and slowly release Sr ions to promote the proliferation and differentiation of MC3T3-E1 cells. The in vivo assessment verified not only the satisfactory antibacterial effect but also the superior osteogenic ability of the NiS@SrTiO3/Ti group with the aid of NIR irradiation, finally promoting the osseointegration of the Ti implant. The modification method endowing Ti implant with antibacterial, angiogenic, and osteogenic functions provides a new strategy to improve the long-term reliability of Ti-based devices.

The Effect of Antibacterial-Osteogenic Surface Modification on the Osseointegration of Titanium Implants: A Static and Dynamic Strategy

“…Ti implants with photoresponsive properties can fully utilize the multiple functions of dynamic self-regulation due to the nanocoated structures (NiS@SrTiO 3 , TiO 2 @Qr/LA) on their surfaces (Figure A and C). Under irradiation with 808 nm NIR, the antibacterial rate of NiS@SrTiO 3 against E. coli and S. aureus reached 96.5% and 93.1%, respectively (Figure B).…”

“…Photographs of E. coli and S. aureus colonies (a), relative bacterial survival (b), live/dead staining images of S. aureus (c). and morphology of E. coli and S. aureus on Ti and NiS@SrTiO 3 / Ti after 15 min of 808 nm laser irradiation (d) . Reproduced with permission from ref .…”

“…and morphology of E. coli and S. aureus on Ti and NiS@SrTiO 3 / Ti after 15 min of 808 nm laser irradiation (d) . Reproduced with permission from ref . Copyright 2023 American Chemical Society.…”

Activating Angiogenesis and Immunoregulation to Propel Bone Regeneration via Deferoxamine-Laden Mg-Mediated Tantalum Oxide Nanoplatform

“…Considering that critical bone defects are not self-healing, highly bioactive artificial implants or fillers seem to be the ideal solution for bone repair. A large amount of work has been done for enhancing osteogenic activity, , but reconstruction of critical bone defects is a complex healing process involving endothelial cell (EC)-dominated angiogenesis that can be replenished with oxygen, nutrients, and growth factors, as well as bone marrow mesenchymal stem cell (BMSC)-dominated osteogenesis that generates extracellular matrix (ECM) and mineralization . Bone is a highly vascularized tissue that supports local tissue repair and survival.…”