Improved osteoblast compatibility of medical‐grade polyetheretherketone using arc ionplated rutile/anatase titanium dioxide films for spinal implants

Abstract

Titanium dioxide (TiO(2)), known to exhibit good biocompatibility, is applied in this study as a thin film formed onto polyetheretherketone (PEEK) substrate, which has been widely used in spinal interbody fusion cages. For successful deposition, an arc ionplating (AIP) technique was applied to deposit TiO(2) at low deposition temperature without damaging PEEK substrate, while providing satisfactory film adhesion. This study systematically investigates the effects of TiO(2) thin film phase composition and surface characteristics, controlled by using different target current and substrate bias, on osteoblast compatibility. Experimental results showed that anatase phase (A-TiO(2)) and/or rutile phase (R-TiO(2) ) TiO(2) coatings, respectively, can be prepared in appropriate deposition conditions. Overall, the TiO(2)-coated PEEK presented better osteoblast compatibility than the bare PEEK material in terms of cell adhesion, cell proliferation, and cell differentiation abilities, as well as osteogenesis performance (as determined by levels of osteopontin, osteocalcin, and calcium content). Surface roughness and hydrophilicity of the AIP-TiO(2) films were found to be responsible for significant osteoblast cell growth. It is also noticeable that the R-TiO(2) exhibited better osteoblast compatibility than the A-TiO(2) due to the presence of negatively charged hydroxyl groups on R-TiO(2) (110) surface in nature.

Anticorrosive, Antimicrobial, and Bioactive Titanium Dioxide Coating for Surface‐modified Purpose on Biomedical Material

“…These three indicators confirmed the osteoblast compatibility of the TiO 2 -coatings deposited on PEEK. Furthermore, the osteogenesis performance (revealed by OPN, OCN, and calcium content as shown in Figure 6(d)-(f) [36], respectively) demonstrated that TiO 2 coatings also significantly increased the osteogenesis performance. This suggests that TiO 2 coatings enhance extracellular bone matrix growth.…”

“…Next, the cell morphology that had attached to the PEEK and TiO 2 -coated PEEK specimens was observed using field emission scanning electron microscopy (FESEM; Hitachi S-4800). Figure 6 shows the osteoblast cell adhesion ability, cell proliferation ability, cell differentiation ability, and osteogenesis performance on the PEEK and TiO 2 -coated PEEK specimens at various deposition conditions [36]. Notably, the osteoblast cell adhesion, proliferation, and differentiation abilities on TiO 2 -coated PEEK specimens were superior to the bare PEEK specimens for all of the deposition conditions.…”

“…Figure 6 [36] also shows that the specimen 90A30V, which was the richest in R-TiO 2 phase, exhibited the most osteoblast compatibility. Figure 7 shows the morphologies of the osteoblast cells after they were cultured for 0.5 and 48 h on PEEK and TiO 2 -coated PEEK specimens at different deposition conditions [36]. Specifically, the morphology of osteoblast cells on the bare PEEK specimens remained spherical without the appearance of filopodium, suggesting the poor adhesion to the specimen.…”

“…Consequently, various surface modification approaches have been developed to promote the hydrophilic and biological characteristics of PEEK, such as using plasma treatment to change the surface chemistry [29], using chemical treatment to graft functional groups [30], and using laser treatment to roughen the surface [31]. Moreover, adding a functional coating to PEEK to create a bioactive surface is a more effective method for enhancing osseointegration performance [32][33][34][35][36][37][38]. Functional coating materials include HA [32], titanium [33,34], TiO 2 [35][36][37], and diamond-like carbon [38].…”

“…Moreover, adding a functional coating to PEEK to create a bioactive surface is a more effective method for enhancing osseointegration performance [32][33][34][35][36][37][38]. Functional coating materials include HA [32], titanium [33,34], TiO 2 [35][36][37], and diamond-like carbon [38]. To date, by taking the advantage of good biocompatibility of titanium with human body, very thick titanium produced over PEEK surface via vacuum plasma spray for spinal implant has been clinically available.…”