Improved Cell Adhesion and Osseointegration on Anodic Oxidation Modified Titanium Implant Surface

Abstract

Although titanium material is currently widely used in dental and orthopedic application, the bio-inertness of Ti impairs its further use. We previously reported the good bioactivity and biocompatibility of TiO 2 nanotube layer fabricated by anodic oxidation technique using in vitro tests. In the present work, we further clarify the cell adhesion and osseointegration properties of anodized surface through both in vitro and in vivo tests. After anodic oxidation (AO), the structure of nanotubes was confirmed by scanning electron microscopy. The surface roughness and hydrophilic properties of the AO and pristine Ti surfaces were evaluated by atomic force microscopy and contact angle measurement test, respectively. It was found that the AO surface displayed moderately higher surface roughness and obviously increased wettability, compared to the original Ti surface. In vitro cellular activity tests demonstrated that osteoblast cells cultured on the AO surface exhibited a much well-spread cytoskeleton organization with more stretched actin filaments, compared to those cultured on the Ti surface. The adherent cell number was also higher on the AO surface than the pure Ti substrate. In addition, we explore the molecular basis of mechanism by analyzing gene expression levels of adhesion and osteogenesis-related genes in MC3T3-E1 cells cultured on different surfaces using quantitative real-time PCR. Increased mRNA levels of vinculin, collagen type 1, osteopontin and osteocalcin were found on the AO surface, compared with the control group. Furthermore, in vivo animal experiment using a rat model revealed that anodized implant surface promotes osseointegration and demonstrated higher bone bonding strength compared to the pure Ti substrate. Our study revealed the superior cell adhesion property, increased adherent and osteogenesis-related gene expressions and enhanced osseointegration by anodized surface, thus implying its enlarged application in future.

The Potential of a Surface-Modified Titanium Implant with Tetrapeptide for Osseointegration Enhancement

“…The surface topography of the implant also affects cell characteristics. The nano-surface will alter the adhesion, motility, spread, proliferation, and differentiation of cells [1,10,29,30]. The nano-surface can also influence cell adhesion selectively, which is why osteoblast adhesion was more than fibroblast [30].…”

“…The success rate of dental implants depends on osseointegration, which is initiated by cell adhesion when the implant surface meets the surrounding tissue [1][2][3][4][5][6][7]. Osseointegration failure is characterized by the instability or loosening of the implant, periimplantitis, and bone resorption [1,[8][9][10][11].…”

“…The success rate of dental implants depends on osseointegration, which is initiated by cell adhesion when the implant surface meets the surrounding tissue [1][2][3][4][5][6][7]. Osseointegration failure is characterized by the instability or loosening of the implant, periimplantitis, and bone resorption [1,[8][9][10][11]. Osseointegration is accomplished through two phases involving primary or mechanical stability, which is recognized after implant placement, and secondary or biological stability related to the healing process [12].…”

Nanostructured titanium dioxide for use in bone implants: a short review

“…The nanoscale structure hastened the growth rate of MC3T3-E1 osteoblastic cells by up to 300% to 400%. Several studies [149,174,185,187,192,194,195] also found that cells attached to the surface of nanotubes became increasingly elongated and formed small filopodia, suggesting that they could be used for orthopedic purposes. Over the years, several researchers [144,188,190,192,193,196] have found that the surfaces of TiO 2 nanotubes immersed in simulated body fluid (SBF) favor the formation of osteoblast-like hydroxyapatite, which is critical for osseointegration, with strong adhesion and binding [230,231].…”

“…The results indicated that TiO 2 nanotubes were uniform and caused no inflammation, and that the tissue was normal and healthy. Li et al [187] evaluated the behavior of MC3T3-E1 osteoblasts in experiments with Sprague Dawley rats. After 4 weeks they observed that the anodized implant surface promoted osseointegration.…”