A pH-response multifunctional nanoplatform based on NaGdF4:Yb,Er,Fe@Ce6@mSiO2-DOX for synergistic photodynamic/chemotherapy of cancer cells

Cancer is one of the major diseases that seriously threaten human health. Drug delivery nanoplatforms for tumor treatment have attracted increasing attention owing to their unique advantages such as good specificity and few side effects. This study aimed to fabricate a pH responsive drug release multifunctional nanoplatform NaGdF4:Yb,Er,Fe@Ce6@mSiO2-DOX. In the platform, Fe3+ doping enhanced the fluorescence intensity of NaGdF4:Yb, Er by 5.8 folds, and the mSiO2 shell substantially increased the specific surface area of nanomaterials (559.257 m2/g). The loading rates of chlorin e6 and doxorubicin hydrochloride (DOX) on NaGdF4: Yb,Er,Fe@Ce6@mSiO2-DOX reached 28.58 +/- 0.85% and 87.53 +/- 5.53%, respectively. Additionally, the DOX release rate from the nanoplatform was only 24.4% after 72 h at pH 7.4. However, under tumor microenvironment conditions (pH 5.0), the release rate of DOX increased to 85.3% after 72 h. The nanoplatform could generate reactive oxygen species (ROS) under 980 nm near infrared excitation. Moreover, the nanoplatform exhibited a strong comprehensive killing efficiency against cancer cells. The viabilities of HeLa, MCF-7, and HepG2 cancer cells were only 18.5, 11.4, and 9.3%, respectively, after being treated with a combination of photodynamic therapy and chemotherapy. The constructed nanoplatform exhibits great application potential in cancer treatment. (c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).