The synergistic effect of TiO₂ nanoporous modification and platelet-rich plasma treatment on titanium-implant stability in ovariectomized rats

Abstract

For several decades, titanium and its alloys have been commonly utilized for endosseous implantable materials, because of their good mechanical properties, chemical resistance, and biocompatibility. But associated low bone mass, wear and loss characteristics, and high coefficients of friction have limited their long-term stable performance, especially in certain abnormal bone-metabolism conditions, such as postmenopausal osteoporosis. In this study, we investigated the effects of platelet-rich plasma (PRP) treatment and TiO₂ nanoporous modification on the stability of titanium implants in osteoporotic bone. After surface morphology, topographical structure, and chemical changes of implant surface had been detected by scanning electron microscopy (SEM), atomic force microscopy, contact-angle measurement, and X-ray diffraction, we firstly assessed in vivo the effect of PRP treatment on osseointegration of TiO₂-modified implants in ovariectomized rats by microcomputed tomography examinations, histology, biomechanical testing, and SEM observation. Meanwhile, the potential molecular mechanism involved in peri-implant osseous enhancement was also determined by quantitative real-time polymerase chain reaction. The results showed that this TiO₂-modified surface was able to lead to improve bone implant contact, while PRP treatment was able to increase the implant surrounding bone mass. The synergistic effect of both was able to enhance the terminal force of implants drastically in biomechanical testing. Compared with surface modification, PRP treatment promoted earlier osteogenesis with increased expression of the RUNX2 and COL1 genes and suppressed osteoclastogenesis with increased expression of OPG and decreased levels of RANKL. These promising results show that PRP treatment combined with a TiO₂-nanomodified surface can improve titanium-implant biomechanical stability in ovariectomized rats, suggesting a beneficial effect to support the success of implants in osteoporotic bone.

Keywords:

• TiO₂ nanotubes
• PRP
• titanium implants
• ovariectomized rats

Supplementary materials

Figure S1 Platelet-rich plasma separated by standard two-step centrifugation protocol.

Figure S2 Quantitative analysis of nanopores: radius 20–60 nm, height 10–40 nm.

Notes: (A) AFM scanning image. (B) Quantitative line of A–B and C–D scanning results to reflect the nanopores size. (C) Quantitative result of surface roughness of A–B and C–D scanning line to reflect the nanopores radius.

Abbreviation: AFM, atomic force microscopy.

Table S1 Specific prime sequences of polymerase chain reaction

Acknowledgments

This study was supported by grants from the National Basic Research Program of China (2012CB933902, Program 973) and Science Funds of Yantai (2014WS042).

Disclosure

The authors report no conflicts of interest in this work.