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

Abstract

Cytotoxicity of titanium dioxide (TiO2) thin films on Chinese hamster ovary (CHO-K1) cells was evaluated after 24, 48 and 72 h of culture. The TiO2 thin films were deposited using direct current magnetron sputtering. These films were post-deposition annealed at different temperatures (300, 500 and 800 °C) toward the anatase to rutile phase transformation. The root-mean-square (RMS) surface roughness of TiO2 films went from 2.8 to 8.08 nm when the annealing temperature was increased from 300 to 800 °C. Field emission scanning electron microscopy (FESEM) results showed that the TiO2 films’ thickness values fell within the nanometer range (290–310 nm). Based on the results of the tetrazolium dye and trypan blue assays, we found that TiO2 thin films showed no cytotoxicity after the aforementioned culture times at which cell viability was greater than 98%. Independently of the annealing temperature of the TiO2 thin films, the number of CHO-K1 cells on the control substrate and on all TiO2 thin films was greater after 48 or 72 h than it was after 24 h; the highest cell survival rate was observed in TiO2 films annealed at 800 °C. These results indicate that TiO2 thin films do not affect mitochondrial function and proliferation of CHO-K1 cells, and back up the use of TiO2 thin films in biomedical science.

Electrospun titania fiber mats spin coated with thin polymer films as nanofibrous scaffolds for enhanced cell proliferation

“…Carballo‐Vila et al () prepared rutile surfaces with a homogeneous grain structure that permits good adherence and axonal growth of cultured rat cerebral cortex neurons. Similarly, crystalline TiO 2 thin films showed no cytotoxicity towards CHO‐K1 cells after 72 hr of culture as recently reported by Cervantes et al (), and they observed higher cell viability and proliferation on TiO 2 thin films containing more rutile. Unlike the TiO 2 NPs that can easily penetrate into the cell membrane and are sequestered inside vesicles (Pan et al, ; Uboldi et al, ), the high surface area and an interconnected three‐dimensional porous network of TiO 2 ‐T‐60 fibre mats provide similar characteristics to the fibrous structure of native ECM, thus favouring the attachment and proliferation of fibroblasts on these substrates.…”

Materials and Techniques for Implantable Nutrient Sensing Using Flexible Sensors Integrated with Metal–Organic Frameworks

“…The corresponding fluorescent images in Figure a–c shows the viable (green) and dead (red) cells dyed by Calcein‐AM/PI double‐stain assay after Cu‐MOF, Co‐MOF, and bare electrodes were immersed for 24 h. The images show that there are more than 99% of living cells with and without the presence of MOFs, suggesting that the MOF‐modified sensors are biologically safe. The cytotoxicity was also conducted using 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide (MTT) assay, the cells viability within the culture solution immersed with sensors modified with Cu‐MOF and Co‐MOF is 95% and 84% compared with the control group (Figure d), satisfying the required 70% cell viability as recommended by USP(ISO 10993‐5) . The better cell viability of Cu‐MOF may suggest that stable Cu‐MOF may be more biocompatible to cells.…”

Crystallinity of TiO2 nanotubes and its effects on fibroblast viability, adhesion, and proliferation

“…These data corroborate with our results, where there was a slight increase in cell proliferation on day 7 for the samples annealed at 530 and 630°C. In another study, Cervantes et al [59] observed an increase of CHO-K1 ovary cells viability on TiO 2 thin films, annealed at >500°C. The authors attributed this cell's growth to the increase in average roughness at the nanoscale due to transformation from anatase to rutile.…”