Cytotoxicity Evaluation and Subcellular Location of Titanium Dioxide Nanotubes

Advantages and prospects of stem cells in nanotoxicology

Nanomaterials have been widely used in many fields, especially in biomedical and stem cell therapy. However, the potential risks associated with nanomaterials applications are also gradually increasing. Therefore, effective and robust toxicology models are critical to evaluate the developmental toxicity of nanomaterials. The development of stem cell research provides a new idea of developmental toxicology. Recently, many researchers actively investigated the effects of nanomaterials with different sizes and surface modifications on various stem cells (such as embryonic stem cells (ESCs), adult stem cells, etc.) to study the toxic effects and toxic mechanisms. In this review, we summarized the effects of nanomaterials on the proliferation and differentiation of ESCs, mesenchymal stem cells and neural stem cells. Moreover, we discussed the advantages of stem cells in nanotoxicology compared with other cell lines. Finally, combined with the latest research methods and new molecular mechanisms, we analyzed the application of stem cells in nanotoxicology.

Acute and Subacute Toxicity Study of Graphene-Based Tumor Cell Nucleus-Targeting Fluorescent Nanoprobes

Graphene-based tumor cell nuclear targeting fluorescent nanoprobes (GTTNs) were synthesized in our laboratory as a kind of nanomaterial and showed good performance for both in vivo and in vitro imaging. GTTNs directly cross the cell membrane and specifically target the tumor cell nucleus via a cell membrane permeability targeting (CMPT) mechanism, which takes advantage of the increased permeability of the tumor cell membranes. GTTNs with a CMPT mechanism achieve high targeting efficiency in tumor tissues. With the tumor cell nucleus-targeting characterization, the GTTN distinguishes tumor cells at the single-cell level and recognizes the tumor tissue interface in a very early stage and shows great potential in clinical applications. Toxicity studies are extremely critical for clinical applications. Therefore, we studied the acute and subacute toxicity of GTTNs using an in vivo method and examined the following experimental indicators: mouse body weight, organ coefficients, serum biochemical parameters, and histological changes. The results showed that there were no significant differences in any indicators between the experimental and control mice. We also used an in vitro method to study the cytotoxicity of GTTNs in GES-1 (gastric epithelial cell) cells. Surprisingly, the results demonstrated over 80% cell viability when the incubation time reached up to 72 h under a 200 mg/L concentration of GTTNs, which indicated that GTTNs had low cytotoxicity. GTTNs barely showed any acute or subacute toxicity or cytotoxicity in vivo and in vitro, respectively, which supports their use for clinical applications.

Insights into Theranostic Properties of Titanium Dioxide for Nanomedicine

Titanium dioxide (TiO2) nanostructures exhibit a broad range of theranostic properties that make them attractive for biomedical applications. TiO2 nanostructures promise to improve current theranostic strategies by leveraging the enhanced quantum confinement, thermal conversion, specific surface area, and surface activity. This review highlights certain important aspects of fabrication strategies, which are employed to generate multifunctional TiO2 nanostructures, while outlining post-fabrication techniques with an emphasis on their suitability for nanomedicine. The biodistribution, toxicity, biocompatibility, cellular adhesion, and endocytosis of these nanostructures, when exposed to biological microenvironments, are examined in regard to their geometry, size, and surface chemistry. The final section focuses on recent biomedical applications of TiO2 nanostructures, specifically evaluating therapeutic delivery, photodynamic and sonodynamic therapy, bioimaging, biosensing, tissue regeneration, as well as chronic wound healing.