EGF Conjugation Improves Safety and Uptake Efficacy of Titanium Dioxide Nanoparticles

Titanium dioxide nanoparticles (TiO(2) NPs) have a strong potential for cancer therapeutic and bioimaging applications such as photodynamic therapy (PDT) and photodynamic diagnosis (PDD). Our previous results have shown that TiO(2) NPs have a low cellular uptake and can induce cell proliferation. This suggests that TiO(2) NPs could increase the risk of tumor overgrowth while being used for PDD and PDT. To solve this problem, we constructed epidermal growth factor-ligated polyethylene glycol-coated TiO(2) NPs (EGF-TiO(2) PEG NPs). In this work, we studied the effect of EGF conjugation on the cellular uptake of TiO(2) PEG NPs. Then, we investigated the effect of both non-conjugated and EGF-TiO(2) PEG NPs on the A431 epidermal cancer cell line, proliferation and growth via the investigation of EGFR localization and expression. Our results indicated that TiO(2) PEG NPs induced EGFRs aggregation on the A431 cells surface and induced cell proliferation. In addition, EGF-TiO(2) PEG NPs induced the internalization of EGFRs inside of cells with increased cellular NPs uptake and decreased cellular proliferation compared to TiO(2) PEG NPs-treated cells. These findings suggest that EGF conjugation can increase the efficacy of TiO(2) PEG NPs for biomedical applications such as PDD and PDT with decreased risk of tumor overgrowth.