Combined chemo and photo therapy of programmable prodrug carriers to overcome delivery barriers against nasopharyngeal carcinoma.

Indocyanine green (ICG) has been employed in medical diagnostics due to its superior photophysical characteristics. However, these advantages are offset by its quick body clearance and inferior photo-stability. In this work, programmable prodrug carriers for chemotherapy/PDT/PTT against nasopharyngeal carcinoma (NPC) were created in order to increase photo-stability and get around biochemical hurdles. The programmable prodrug carriers (PEG-PLA@DIT-PAMAM) that proactively penetrated deeply into NPC tumors and produced the deep phototherapy and selective drug release under laser irradiation was created by dendrimer-DOX/ICG/TPP (DIT-PAMAM) and PEGylated poly (α-lipoic acid) (PLA) copolymer. Long circulation times and minimal toxicity to mammalian cells are two benefits of PEG-coated carriers. The overexpressed GSH on the tumor cell or vascular endothelial cell of the NPC disintegrated the PEG-g-PLA chains and released the DIT-PAMAM nanoparticles after the carriers had reached the NPC tumor periphery. Small, positively charged DIT-PAMAM nanoparticles may penetrate tumors effectively and remain inside tumor for an extended period of time. In addition, the induced ROS cleaved the thioketal linkers for both DOX and nanoparticles and product hyperthermia (PTT) to kill cancer cells under laser irradiation, facilitating faster diffusion of nanoparticles and more effective tumor penetration with a programmable publication of DOX. The programmable prodrug carries showed high photo-stability high photo-stability, which enabled very effective PDT, PTT, and tumor-specific DOX release. With the goal of combining the effects of chemotherapy, PDT, and PTT against NPC, this research showed the great efficacy of programmable prodrug carriers.