The Assessment of Photo-Induced Toxicity of [NaYF4:Yb3+, Er3+] Upconversion Nanoparticles on Model Normal and Cancer Cell Lines in Vitro

Upconversion nanoparticles (UCNPs) are promising alternatives to traditional fluorescent labels for cell imaging that have outstanding potential in biological and clinical applications. As we previously established, the co-incubation of synthesized in-house [NaYF 4 :Yb 3+ , Er 3+ ] UCNPs uncoated and coated by SiO 2 shell with the cell lines resulted in particles' uptake. Because of the tendency to particle internalization by cells, the assessment of the biocompatibility of UCNPs intended for biomedical applications and their ability to induce desirable biological effects under the appropriate wavelength irradiation is an important step in UCNPs development. The present work is focused on the assessment of [NaYF 4 :Yb 3+ , Er 3+ ] UCNPs' phototoxicity and changes in human lung-derived embryonic fibroblast (FLEH-104) and human laryngeal epidermoid carcinoma (Hep-2) cell lines' morphology in response to the influence of UCNPs.