Integration of chemotherapy and phototherapy based on a pH/ROS/NIR multi-responsive polymer-modified MSN drug delivery system for improved antitumor cells efficacy

Abstract

Due to the difference of the intracellular microenvironment between tumor and normal cells, many stimuli-responsive drug carriers have been developed for precise drug delivery and improved treatment effect. In this paper, a multi responsive drug delivery system based on mesoporous silica nanoparticle (MSN) was prepared. A pH/ROS-sensitive polymer was designed and used to attach to the MSN surface, which acted as a smart nano-valve to prevent premature leakage of drugs. The carrier has been proved to release drugs selectively in simulated tumor microenvironment with lower pH and higher ROS content. And, by co-loading a photosensitizer with antitumor drug, the carrier could produce exogenous ROS under the near-infrared light irradiation, resulting in much quicker removing of the polymer and more drug release. Furtherly, the antitumor effect was evaluated by CCK-8 assay using normal and tumor liver cells. In short, the results of drug release and cell experiments both showed that the carriers had excellent anti-tumor cells effects.