Titanium Oxide Nanoparticles as Posible Antioxidant for Cryopreservation

The original method for synthesizing TiO2-x nanoparticles (NPs) has been described. By varying the amount of nitric acid as a catalyst and peptizing agent, two types of TiO2-x NPs with the same size of approximately 5 nm but different Ti³⁺ (Ti²⁺)/Ti⁴⁺ ratios have been successfully obtained in the form of water colloidal solutions. The structure and properties of the resulting TiO2-x samples have been thoroughly analyzed using TEM, XRD, and XPS techniques. Cytotoxicity studies have confirmed the excellent biocompatibility of both sets of TiO2-x NPs. Furthermore, the efficacy of TiO2-x NPs in cryopreservation has been assessed through slow freezing of NIH 3T3 cell suspensions. This assessment has been conducted using trypan blue exclusion tests, propidium iodide staining, Resazurin assays, and an analysis of cell proliferative activity. Overall, these findings provide valuable insights into the potential applications of TiO2-x NPs in cryopreservation, highlighting their biocompatibility and utility in preserving cell viability during freezing processes.