# Nanozymes based on functionalized iridium oxide-modified gold nanoparticles for combination therapy

## TL;DR

Researchers developed nanozymes combining iridium oxide and gold nanoparticles for effective cancer treatment using light.

## Contribution

A new nanozyme (PIrS@Au) is developed for tumor combination therapy with improved photothermal and catalytic properties.

## Key findings

- PIrS@Au nanozymes were effectively taken up by HeLa and HepG2 cells.
- Inhibition of cell growth was observed after near-infrared irradiation in an oxidative environment.
- At 400 µg mL−1, HeLa and HepG2 cell survival rates dropped to 35.6% and 46.8%, respectively.

## Abstract

Combination therapy has become the trend in cancer treatments. Iridium oxide-based nanoparticles have shown potential for application in tumour therapy due to their excellent photophysical-chemical and hydrogen peroxide-like enzymatic activities. However, during the practical application of functionalized iridium oxide, it was observed that a high-power near-infrared laser (NIR) is required to achieve better results. The excellent photothermal conversion efficiency of gold nanoparticles has been widely verified. Based on these facts, nanozymes based on functionalized iridium oxide-modified gold nanoparticles (PIrS@Au) were developed. PIrS@Au with good photothermal conversion efficiency, photochemical activity, catalase-like activity and biocompatibility could be effectively taken up by HeLa and HepG2 cells. In vitro, the growth of HeLa and HepG2 cells cultured with PIrS@Au in an oxidative environment was inhibited after irradiation with 808 nm near-infrared light for 5 minutes (2.2 W cm−2) twice. In particular, in the experimental group, where the concentration of PIrS@Au was the highest at 400 µg mL−1, the survival rates of HeLa and HepG2 cells were 35.6% and 46.8%, respectively. In conclusion, PIrS@Au shows potential application in tumour combination therapy.

A facile strategy to prepare nanozymes based on functionalized iridium oxide-modified gold nanorod is presented.