Titanium implants with antiaging effect to repair senile osteoporosis fracture

Accelerated population ageing has brought a great burden to the development of society. Repairing senile osteoporosis fractures is a great challenge, but a desirable way to address this issue is by developing multifunctional titanium(Ti) implants with antiaging and pro-osteogenic effects. Herein, to endow TI substrate with an antiaging effect for enhanced bone formation, an exercise-induced myokine(irisin) was loaded on titanium dioxide nanotubes(TNTs) and then a multilayered structure composed of chitosan(Chi) and gelatin(Gel) was constructed on the substrates via a layer-by-layer-assembly technique(TNT-IR-LBL). The surface topography of TNT-IR-LBL was characterized by scanning electron microscopy (SEM), atomic force microscopy(AFM), X-ray photoelectron spectroscopy(XPS) and water contact angle measurements, respectively. As an exercise-induced myokine, the irisin secreted from skeletal muscle exhibits strong activity for against the chronic diseases. The implants synthesized here displayed good biocompatibility towards osteoblasts. Moreover, irisin was sustainably released from TNT-IR-LBL for more than 3 weeks. In vitro studies indicated the TNT-IR-LBL substrates promoted osteoblast differentiation. In addition, compared to bare titanium, TNT-IR-LBL significantly promoted new bone formation around the implant interface in senile osteoporosis rats 4 weeks after implantation. Overall, this study provides a promising candidate to develop Ti-based orthopaedic implants to repair senile osteoporosis fractures.