Ag-doping regulates the cytotoxicity of TiO2 nanoparticles via oxidative stress in human cancer cells

Abstract

We investigated the anticancer potential of Ag-doped (0.5–5%) anatase TiO2 NPs. Characterization study showed that dopant Ag was well-distributed on the surface of host TiO2 NPs. Size (15 nm to 9 nm) and band gap energy (3.32 eV to 3.15 eV) of TiO2 NPs were decreases with increasing the concentration of Ag dopant. Biological studies demonstrated that Ag-doped TiO2 NP-induced cytotoxicity and apoptosis in human liver cancer (HepG2) cells. The toxic intensity of TiO2 NPs was increases with increasing the amount of Ag-doping. The Ag-doped TiO2 NPs further found to provoke reactive oxygen species (ROS) generation and antioxidants depletion. Toxicity induced by Ag-doped TiO2 NPs in HepG2 cells was efficiently abrogated by antioxidant N-acetyl-cysteine (ROS scavenger). We also found that Ag-doped TiO2 NPs induced cytotoxicity and oxidative stress in human lung (A549) and breast (MCF-7) cancer cells. Interestingly, Ag-doped TiO2 NPs did not cause much toxicity to normal cells such as primary rat hepatocytes and human lung fibroblasts. Overall, we found that Ag-doped TiO2 NPs have potential to selectively kill cancer cells while sparing normal cells. This study warranted further research on anticancer potential of Ag-doped TiO2 NPs in various types of cancer cells and in vivo models.

A titanium dioxide/nitrogen-doped graphene quantum dot nanocomposite to mitigate cytotoxicity: synthesis, characterisation, and cell viability evaluation

“…10 One of the promising strategies to overcome this toxicity issue is via surface modication by fabricating semiconductor heterojunctions. For example, the materials can be incorporated with additional components including transition metals (Cu, Zn and Fe), 11,12 noble metals (Ag, Pt and Pd) 13,14 and other semiconductors (CdS, CdSe and NiO). [15][16][17] Most of conventional transition metals, semiconductors and noble metals are unstable or induce toxicity leading to environmental issues and impeding their benets except Fe metal, since the excited electrons in conduction band is taken up by Fe 3+ .…”

Visible-Light Active Titanium Dioxide Nanomaterials with Bactericidal Properties

“…Conflicting results are reported in the literature regarding the biocompatibility and cytotoxicity of TiO 2 NPs. Some studies indicate a good biocompatibility of TiO 2 NPs with mammalian cells [166,201,309,318], while others reveal the toxic effects of TiO 2 NPs [319][320][321][322][323][324][325]. The discrepancy is attributed to the biological and materials factors involved during in vitro studies.…”

“…Therefore, metal-doped TiO 2 NPs photocatalysts can fulfill the requirement of bactericidal performance, but they pose potential human health and safety hazards following long-term exposure. Recently, Ahamed et al employed MTT and neutral red uptake (NRU) assays to assess the metabolic and lysosomal activities of human liver cancer (HepG2) cells exposed to Ag (0.5-5%)-doped TiO 2 NPs [318]. Their results showed that Ag-doped TiO 2 NPs reduce the cell viability in a dose-dependent manner, as shown in Figure 34a,b.…”

A Safe‐by‐Design Strategy towards Safer Nanomaterials in Nanomedicines

“…Besides, the formation of heterostructures on nanocrystal surfaces can lead to a local change in the energy offset of band structure near the surface (e.g., band bending effect), promoting charge separation in the heterostructure . Both of these events may influence the energy level alignment in the doped nanocrystals and therefore affect its ROS generation and oxidative stress …”