Enhanced biological responses of a hydroxyapatite/TiO<Sub>2</Sub> hybrid structure when surface electric charge is controlled using radiofrequency sputtering

Abstract

We investigated whether surface roughness and control of surface electric charge of a hydroxyapatite (HA)/titanium oxide (TiO2) hybrid coating could enhance biological responses associated with bone formation. After acid etching, a titanium surface was modified with HA and TiO2 by the dual sputtering deposition technique using radiofrequency sputtering. These surfaces were analyzed for surface roughness and surface electric charge intensity. Rat bone marrow-derived osteoblast-like cells were cultured on HA/TiO2 hybrid surfaces with different electric charges. The attachment and spreading behavior of these cells were significantly increased on the hybrid surface (p<0.05). In vivo experiment, the strength of bone-titanium implant integration with a hybrid surface was 3 times that of a control (p<0.05). The dual sputtering deposition technique created a HA/TiO2 hybrid structure. Our results show that the surface electric charge on a titanium surface is an important factor for enhancing biological responses.

MC3T3-E1 cell response to stainless steel 316L with different surface treatments

“…In the past few years, an amount of studies have been performed to investigate the molecular and cellular reactions of the host to the implanted prostheses with different surface treatments, such as composition [9], morphology/roughness [10,11], structure [12], and surface charge [13]. It is demonstrated that the osteoblastic cells tend to attach preferentially to blasted or plasma sprayed surfaces with a rougher topography, while the fibroblast cells favor smooth surfaces [14].…”

Biokinetics and tissue response to ultrananocrystalline diamond nanoparticles employed as coating for biomedical devices

“…Adhesion of the coating to the substrate is a critical issue from the perspective of the mechanical performance and biocompatibility of the coated‐implant . Although UNCD shows strong adhesion to substrates, the potential release of particulate material into the biological milieu cannot be ruled out.…”

“…19 Adhesion of the coating to the substrate is a critical issue from the perspective of the mechanical performance and biocompatibility of the coated-implant. 17,18,33 Although UNCD shows strong adhesion 17 to substrates, the potential release of particulate material into the biological milieu cannot be ruled out. It is therefore important to evaluate its possible biological effects and degree of toxicity as compared to TiO 2 particles that could be released from titanium implants.…”

Vertical bone augmentation induced by ultrathin hydroxyapatite sputtered coated mini titanium implants in a rabbit calvaria model

“…Cellular events present at the interface may be affected by the surface modifications leading to different outcomes on the rate and amount of new bone formation . Hydroxyapatite (HA) coating of dental implants has been used to improve surface characteristics that convert the titanium surface to become bioactive with high bone‐bonding property . Conventional methods such as plasma spraying has been used to coat titanium surface with HA, however, this results in a thick coated layer (50 µm) of HA that has many disadvantages including nonuniformity in the coating density, microcracks on the coating surface, and poor resistance to delamination .…”

“…Recently, improvements in coating techniques can produce an ultrathin layer of HA coating (1 µm thickness) on the surface of titanium using a novel sputtering technique. This technique can produce strong adhesion, compact microstructure, controlled elemental composition, and preserve the surface roughness of the underlying substrate . In vivo study, osseointegration was rapidly enhanced with using the sputtered HA coated implants and no connective tissue was observed .…”