Cytotoxic effects of NIR responsive chitosan-polymersome layer coated melatonin-upconversion nanoparticles on HGC27 and AGS gastric cancer cells: Role of the ROS/PI3K/Akt/mTOR signaling pathway.

In this study, a formulation of NaGdF:Tm/Er@NaGdF (core@shell) UCNPs loaded with melatonin drug was synthesized. The novel melatonin-loaded UCNPs were then encapsulated within NIR-responsive biopolymeric chitosan (CS) based polymersome and investigated against gastric cancer (HGC27 & AGS) cells. The photolysis of the ONB moiety and disruption of the disulfide linkage in the polymersome induced by NIR light facilitated by the NaGdF:Tm/Er@NaGdF UCNPs and GSH results in an increased release of melatonin drug.