Biocompatibility and Surface Properties of TiO2 Thin Films Deposited by DC Magnetron Sputtering

Abstract

We present the study of the biocompatibility and surface properties of titanium dioxide (TiO2) thin films deposited by direct current magnetron sputtering. These films are deposited on a quartz substrate at room temperature and annealed with different temperatures (100, 300, 500, 800 and 1100 °C). The biocompatibility of the TiO2 thin films is analyzed using primary cultures of dorsal root ganglion (DRG) of Wistar rats, whose neurons are incubated on the TiO2 thin films and on a control substrate during 18 to 24 h. These neurons are activated by electrical stimuli and its ionic currents and action potential activity recorded. Through X-ray diffraction (XRD), the surface of TiO2 thin films showed a good quality, homogeneity and roughness. The XRD results showed the anatase to rutile phase transition in TiO2 thin films at temperatures between 500 and 1100 °C. This phase had a grain size from 15 to 38 nm, which allowed a suitable structural and crystal phase stability of the TiO2 thin films for low and high temperature. The biocompatibility experiments of these films indicated that they were appropriated for culture of living neurons which displayed normal electrical behavior.

Cytotoxicity Evaluation of Anatase and Rutile TiO2 Thin Films on CHO-K1 Cells in Vitro

“…The MTT assay demonstrated they had normal mitochondrial function. These results are consistent with previous data where dorsal root ganglion neurons from the rat were maintained in culture for 18 and 24 h on TiO 2 thin films retaining their normal electrophysiological properties, proving they were viable and functionally similar to those grown on the control substrate [12]. In contrast to neuronal cultures where cells do not reproduce, the use of CHO-K1 cells added information about the proliferation and metabolic capabilities of living cells on TiO 2 films.…”

“…The increase in the annealing temperature increased the average roughness up to 8.08 nm (Table 2) due to a transformation from the anatase to rutile phase [12,31] as the X-ray diffraction patterns for TiO 2 thin films annealed at different temperatures show (Figure 5). The X-ray diffraction pattern of the TiO 2 thin film, post-deposition-annealed at 800 °C, revealed the coexistence of anatase and rutile phases; the intensity of the rutile phase compared to the anatase phase increased as a result of the increment of the thermal annealing treatment.…”

“…Previous studies have shown that the surface of TiO 2 thin films deposited by direct current magnetron sputtering had good quality, homogeneity, roughness, and biocompatibility. These films were suitable for the culture of functional living neurons that display normal electrical behavior [12]. On account of these findings, we proposed these TiO 2 thin films to be deposited on the microelectrode surface and the readout circuit of complementary metal oxide semiconductor and micro-electromechanical systems (CMOS-MEMS) for biomedical applications [12,13], for which evaluation of their potential cytotoxicity is required.…”

“…These films were suitable for the culture of functional living neurons that display normal electrical behavior [12]. On account of these findings, we proposed these TiO 2 thin films to be deposited on the microelectrode surface and the readout circuit of complementary metal oxide semiconductor and micro-electromechanical systems (CMOS-MEMS) for biomedical applications [12,13], for which evaluation of their potential cytotoxicity is required. In order to avoid experimental animal exposure to unjustified risk, studying in vitro cytotoxicity is an essential step prior to the use of TiO 2 thin films on living animals [14,15].…”

Atomic layer deposition of nano-TiO_2 thin films with enhanced biocompatibility and antimicrobial activity for orthopedic implants

“…[21][22][23][24][25][26] In selecting an appropriate deposition technology for this specific application, several criteria have to be considered such as coating morphology, deposition rate and coverage, interfacial quality, and industrial applicability. Among these methods, the ALD process is based on the sequential use of self-terminating surface reactions, which is perfect for the deposition of metal oxide layers with atomic layer control on geometrical nanostructures with high aspect ratios.…”