Bioactivatable Self-quenched Nanogel for Targeted Photodynamic Therapy

Photodynamic therapy attracted significant attention due to its localized treatment advantage. However, the non-specific distribution of photosensitizer and subsequent potential toxicity caused by sunshine exposure hinders its wild adoption in cancer treatment. To minimize this unwanted effect and improve its efficacy, we developed a bioactivatable self-quenched nanogel, which remains in its inactivated state in healthy tissues. Anti-EGFR Affibody decorated nanogels can effectively target head and neck cancer and liberate activated Pheophorbide A in a reducing environment, such as a tumor stroma and cytoplasm. Consequently, the EGFR targeted nanogel coupled with NIR irradiation alleviate tumor burden by 94.5% while not inducing systemic toxicity.