Biodegradable Silica-Based Nanoparticles with Improved and Safe Delivery of Protoporphyrin IX for the In Vivo Photodynamic Therapy of Breast Cancer

Silica-based nanoplatforms are highly versatile and attractive delivery systems for cancer treatment. These platforms have been used for the effective delivery of pharmacological agents in preclinical settings. Though silicon oxide is found naturally in the human body, a major limitation associated with silica-based nanoparticles is their slow biodegradability. Therefore, the potential risks related to the longer bioaccumulation of these materials can be significant. In this work, the synthesis and application of a novel silica-based nanoplatform, polysilsesquioxane nanoparticles (PSilQ NPs) is reported. The developed PSilQ material contains stimuli-responsive properties, and improves biodegradability for the efficient delivery of a clinically relevant photosensitizer, protoporphyrin IX. Herein, it is demonstrated that the PSilQ nanoplatform is biocompatible and exhibits enhanced biodegradability in an immune-competent mouse model. In addition, PSilQ NPs show phototherapeutic efficiency for reducing the tumor burden in an orthotopic model of triple-negative breast cancer. These results may pave the way for the future clinical evaluation of this silica-based nanoplatform. (AU)