Encapsulation of glucose oxidase in Fe(III)/tannic acid nanocomposites for effective tumor ablation via Fenton reaction.

Increasing the content of reactive oxygen species (ROS) with the assistance of nanoformulations in cancer cells via Fenton reaction is considered to be an effective method to treat cancer. However, the efficiency of Fenton reaction is affected by the level of HO, the selection of iron ions in different nanoformulations, etc. Herein, we use the Fe-tannic acid (FeTA) nanocomposites as the carrier to deliver glucose oxidase (GOD) that can solve the problem of insufficient endogenous HO by catalytically converting the glucose. In comparison with traditional Fe/Fe, FeTA nanocomposites perform higher catalytic activity in converting HO to high toxic hydroxyl radicals (•OH) due to the TA-mediated reduction of Fe. So, the integration of GOD and TA in the construction of nanocomposites significantly enhances the efficiency of Fenton reaction. In vitro experiments show that •OH produced by GOD-Fe TA nanocomposites can not only achieve a good anticancer effect at a low concentration but also promote degradability of the nanocomposites. When it is only 1.08 μg•mL, the cell apoptosis rate has reached 76.91%. And in vivo experiments further demonstrate that GOD-FeTA nanocomposites can significantly inhibit the tumor growth. So this work lays a good foundation for Fenton reaction-based cancer treatment.