Regulating water states by vacancies for cancer therapy

Abstract

The conversion of bulk water to confined water in biological tissues has been proposed to benefit the treatments of diseases. However, regulating the states of water in vivo is still a challenge. Herein, we constructed nanocatalysts (BiOCl) containing abundant superficial vacancies to confine water in situ and investigated the potential utilization in cancer radiotherapy. Vacancies absorbed bulk water, transformed its structure and converted it to confined water. Enhanced reactivity of confined water increased the efficiency of water radiolysis and the yield of hydroxyl radicals (·OH) from radiation exposure. The results validated the feasibility of water-confinement-based radiosensitization strategy. These findings not only provide a method of constructing confined water in vivo , but also present the potentials of confined water for biological applications. We constructed BiOCl nanocatalysts containing bismuth vacancies to confine water for enhanced radiotherapy. Vacancies absorbed bulk water, transformed its structure and converted it to confined water. Enhanced reactivity of confined water increased the efficiency of water radiolysis and the yield of hydroxyl radicals (·OH) in radiotherapy. The results validated the feasibility of water-confinement-based radiosensitization strategy. • Constructing confined water in vivo is achieved by using superficial defects of nanocatalysts. • Confined water could promote the generation of hydroxyl radicals during the process of radiotherapy. • Increasing the reactivity of water during the process of radiotherapy is a feasible way for radiosensitization.