Supercritical Fluid-Assisted Fabrication of Indocyanine Green-Encapsulated Silk Fibroin Nanoparticles for Dual-Triggered Cancer Therapy.

Despite the success and advantages over traditional chemotherapeutic strategies, photothermal therapy (PTT) suffers from certain limitations, such as poor stability, low therapeutic efficacy of PTT agents , and their affinity loss during the multistep synthesis process of delivery carriers, among others. To address these limitations, we designed a stable, biocompatible, and dual-triggered formulation of indocyanine green (ICG)-encapsulated silk fibroin (SF) (ICG-SF) nanoparticles using supercritical fluid (SCF) technology. We demonstrated that ICG encapsulation in SF through this environmental-friendly approach has offered excellent photothermal stability, the pH-responsive release of ICG from SF specifically in the tumor acidic environment, and its substantial activation with near-infrared (NIR) light at 808 nm significantly enhanced the PTT efficiency. and photothermal experiments have shown that these ICG-SF nanoparticles were capable of devastating tumor cells merely under light-induced hyperthermia. Together, these results have suggested that the biocompatible ICG-SF nanoparticles prepared by the SCF process resulted in high PTT efficiency and may have a great potential as a delivery system for sustained cancer therapy.