ROS-activatable biomimetic interface mediates in-situ bioenergetic remodeling of osteogenic cells for osteoporotic bone repair.

Bioenergy (ATP) is essentially required for supporting the osteogenic differentiation of bone marrow mesenchymal stem cells (MSCs). However, factors such as high ROS levels and decreased glucose metabolism severely limit the bioenergy production in osteoporotic MSCs. We have prepared CaCO3-Quercetin- chromium (CaCO3-Qu-Cr) nanoparticles via ion coordination and packaged them into ROS-responsive gelatin/chitosan coating on titanium surface (Ti/Gel/CaCO3-Qu-Cr), aiming to improve the ATP production and cell mineralization by ameliorating ROS levels via Qu-mediated antioxidative effect and the promotional effect of Qu-Cr combination on glucose metabolism. Characterization results confirmed that Ti/Gel/CaCO3-Qu-Cr could be degraded in an ROS-responsive manner to release CaCO3-Qu-Cr nanoparticles continuously and eliminate excessive ROS in both the MSCs and microenvironment. Meanwhile, Ti/Gel/CaCO3-Qu-Cr significantly increased the glucose uptake and metabolism in osteoporotic MSCs and boosted their ATP and citrate production. This study laid the foundation for the development of functional titanium-based implants for the improvement of osteoporotic osseointegration.