Engineered silk fibroin–new indocyanine green dye nanoassembly for photothermal image-guided breast cancer therapy

Noninvasive diagnostic and treatment strategies have long been pivotal in tumor therapy, with the innovative design of photothermal nanoagents being crucial for enhancing therapeutic outcomes. Herein, we introduce an engineering approach that combines biocompatible silk fibroin with a small photothermal molecule, the new indocyanine green dye, resulting in water-soluble silk fibroin–new indocyanine green nanoparticles (designated as SF@IR820 NPs). The dynamic structural design provides SF@IR820 with nanoscale dimensions, excellent biocompatibility, deep tumor penetration, and significant photothermal imaging and therapeutic effects. When exposed to an 808 nm laser, SF@IR820 effectively eliminates 4T1 tumor cells in vitro and inhibits tumor growth in vivo, all while allowing for photothermal imaging monitoring. This study presents a promising approach for developing highly efficient photothermal reagents for cancer treatment.