Enhancement of Local Osseointegration and Implant Stability of Titanium Implant in Osteoporotic Rats by Biomimetic Multilayered Structures Containing Catalpol

This study examined the surface modification of titanium (Ti) implants to enhance early-stage osseointegration, which reduced the failure rate of internal fixation in osteoporotic fractures that inherently decrease in bone mass and strength. We employed a layer-by-layer electroassembly technique to deposit catalpol-containing hyaluronic acid/chitosan multilayers onto the surface of Ti implants. To evaluate the in vitro osteoinductive effects of catalpol-coated Ti implants, the robust osteoblast differentiation capacity of the murine preosteoblast cell line, MC3T3-E1, was employed. Furthermore, the performance of these implants was evaluated in vivo through femoral intramedullary implantation in Sprague–Dawley rats. The engineered implant effectively regulated catalpol release, promoting increased bone formation during the initial stages of implantation. The in vitro findings demonstrated that catalpol-coated Ti surfaces boosted ALP activity, cell proliferation as measured by CCK-8, and osteogenic protein expression via WB analysis, surpassing the uncoated Ti group (P < 0.05). In vivo micro-computed tomography (CT) and histological analyses revealed that catalpol-coated Ti significantly facilitated the formation and remodeling of new bone in osteoporotic rats at 14 days post-implantation. This study outlines a comprehensive and straightforward methodology for the fabrication of biofunctional Ti implants to address osteoporosis.