Engineered photo-responsive materials for near-infrared-triggered drug delivery

Abstract

Near-infrared (NIR) light-responsive drug delivery systems have gained increasing interest in biomedical applications due to their spatiotemporal and on-demand drug release. This review summarizes recent progress in development of various photo-responsive materials for NIR light-triggered drug release, with particular emphasis on their molecular designs and formulations as well as photo-reaction mechanisms. Various NIR light-responsive materials have been developed mainly by incorporating NIR light-responsive photochromic moieties. The photo-reaction mechanisms of NIR light-responsive materials for NIR light-triggered drug release include photo-induced transition of hydrophobicity–hydrophilicity, photo-cleavage reaction, and photo-induced heating, which induce disruption of the drug carriers for drug release. This review also highlights an emerging technology of utilizing upconverting nanoparticles (UCNPs) to significantly enhance the NIR light-sensitivity of the currently developed photo-responsive drug carriers. This review demonstrates that NIR-responsive drug delivery systems capable of spatiotemporal and on-demand drug release are highly desired to translate the promise of drug delivery for clinical therapy.