Hollow mesoporous silica nano-delivery systems based on ultra-thin biodegradable shells a synergistic integration strategy for chemotherapy and photothermal therapy

Mesoporous silica nanoparticles (MSNs) have been discovered to hold substantial potential in tumor treatment due to their ability to enhance drug tumor-targeting capacity and reduce side effects as a nanoparticle drug delivery system. We rationally designed and successfully synthesized hollow mesoporous silica nanoparticles (HMSNs) with a large cavity structure and ultra-thin shells. By incorporating disulfide bonds (-S-S-) and gold nanoparticles (Au NPs) into the framework of the particles, we endowed the system with biodegradable properties and redox-responsive drug release behavior, resulting in biodegradable HMSNs (BHMSNs). Through optimization of shell thickness and composition, BHMSNs were obtained with an average diameter of 120 ± 5 nm and a shell thickness as low as 11.3 nm, exhibiting a high drug loading capacity (900.2 mg/g for DOX) and significant degradation efficiency. Embedding Au NPs into the biodegradable shell further enhanced their degradation performance. Under near-infrared (NIR) light irradiation, the drug delivery system demonstrated excellent photothermal conversion efficiency. Internalization behavior and cytotoxicity assays demonstrate that DOX-BHMSNs@Au can effectively deliver doxorubicin into cells and exhibit significantly enhanced antitumor activity under near-infrared light. This nanocarrier system possesses redox-responsive biodegradability and controlled drug release capabilities, which are promising for cancer therapy.