Osteogenic capability of strontium and icariin-loaded TiO₂ nanotube coatings in vitro and in osteoporotic rats

Abstract

Titanium (Ti) and Ti alloys are widely used biomaterials, but they lack osteogenic capability for rapid bone integration. To improve osseointegration of Ti implants, TiO2 nanotubes were prepared using the anodizing oxidation technique, and strontium (Sr) combined with icariin (ICA) was loaded on TiO2 nanotube coatings. Cell adhesion and proliferation of MC3T3-E1 cells, alkaline phosphatase (ALP) activity, mineralization of extracellular matrix, and bone formation around titanium implants in ovariectomized rats, were examined separately. The results showed that compared with pure Ti, TiO2 and Sr-loaded TiO2 coatings, the coatings loaded with both Sr and ICA showed better effect on cell adhesion and proliferation, higher ALP activity and more red-stained mineralized nodules. Furthermore, more bone was formed around implants loaded with both Sr and ICA in osteoporotic rats. Therefore, coating with Sr and ICA is valuable for clinical application to strengthen the osseointegration of titanium implants, especially in osteoporotic patients.

Macrophage-like Cells Are Responsive to Titania Nanotube Intertube Spacing—An In Vitro Study

“…A possible explanation may be that these nanostructures, mainly TNT80, allowed macrophages to overcome the surface spatial limitations, leading to a higher number of filopodia and implicitly to an enhanced cell adhesion. For instance, this increase in cell attachment was reported to activate actin stress fibres (RhoA)/Rho-associated protein kinase (ROCK) signalling pathway, inducing macrophage activation and sequentially their switch towards a M2 phenotype [ 70 , 71 ].…”

Advances in Multifunctional Bioactive Coatings for Metallic Bone Implants

“…TiO2 nanotubes produced by anodizing and loaded with Sr combined with icariin (ICA) showed a better effect on cell adhesion, proliferation and higher mineralization activity than pure Ti and TiO2 coatings. Furthermore, in osteoporotic rats, more bone was formed around the implants loaded with Sr and ICA [207]. Similarly, Y-doped TiO2 coatings on Ti6Al4V produced by PEO demonstrated good biocompatibility on osteoblastic precursor cells and fibroblast cells with increasing doping concentration of yttrium and excellent antibacterial activity against E. coli and S. aureus [208].…”

Construction of Local Drug Delivery System on Titanium-Based Implants to Improve Osseointegration

“…For instance, Zhu et al loaded ICA on the TNTs and confirmed that ICA-loaded TNTs could accelerate osseointegration via enhancing ECM mineralization and new bone formation. These effects were more remarkable after joining Sr [ 162 ]. Furthermore, the addition of composite coating optimized the local drug delivery system.…”