Synthesis and growth studies of Selenium Nanoparticles for biomedical applications

Selenium nanoparticles (SeNPs) have garnered significant interest due to their potential biomedical applications, particularly in cancer therapy. In this study, SeNPs were synthesized via the chemical reduction of sodium selenite (Na₂SeO₃) in the presence of tannic acid as a capping agent and different reducing agents, namely L-cysteine, L-ascorbic acid, and sodium borohydride (NaBH₄). By varying the concentrations of both the reducing and capping agents, we obtained stable SeNPs with tuneable diameters ranging from 50 nm to 150 nm. The influence of washing cycles on nanoparticle size and stability was also investigated to assess potential aggregation or structural modifications. Furthermore, the density of SeNPs was analysed using an analytical centrifuge, revealing deviations from the bulk selenium density, likely due to nanoporous structures within the nanoparticles. Finally, the anticancer properties of the synthesized SeNPs were evaluated against MDA-MB-231 (breast cancer) and OVCAR3 (ovarian cancer) cell lines. The nanoparticles exhibited dose-dependent toxicity, with IC₅₀ values of 1.23 ± 0.06 μg/mL and 0.91 ± 0.09 μg/mL for MDA-MB-231 and OVCAR3, respectively. These findings contribute to the growing body of knowledge on SeNPs, highlighting their potential for biomedical applications and warranting further investigation into their physicochemical properties and mechanisms of action.