In photodynamic therapy (PDT), the concentration of reactive oxygen species (ROS) generated in cells directly determines the therapeutic effect. However, excessive glutathione (GSH) concentration at the tumor site and hypoxic environment strongly reduce the production of ROS. Nitric oxide (NO) has a variety of anti-tumor activities, including the induction of cell apoptosis and sensitization to PDT, so it is in the spotlight in the area of cancer intervention. Therefore, it is very innovative to combine NO therapy with PDT and simultaneously reduce GSH content and relieve hypoxia. Metal-organic framework (MOF) is an emerging drug delivery vehicle that can exert photodynamic effects when a photosensitizer is used as its organic ligand. In this study, we constructed a GSH-responsive NO producing nanosystem to enhance ROS production through GSH depletion and hypoxia alleviation. Briefly, nicorandil (Nic) is encapsulated into porous porphyrinic MOF nanoparticles, and hyaluronic acid (HA) is electrostatically adsorbed on the surface of the MOF nanoparticles for CD44 receptor-targeting and prevention of Nic leakage. Notably, the Nic reacts with GSH to produce NO gas with vasodilation and GSH reduction, thus improving oxygen supply for efficient ROS generation. Moreover, the generated NO can further react with superoxide radical anion to produce highly reactive peroxynitrite (ONOO − ) molecules with higher cytotoxicity. Overall, the [email protected] nanosystem combines NO gas therapy with PDT, resulting in a significant increase in ROS production and greatly enhancing the efficacy of PDT.
Jing Li,Junhua Li,Yuji Pu,Sai Li,Wenxia Gao,Bin He
In this study, we reported a nanocomplex (PAF) of PEGylated polygalacturonic acid, 5,10,15,20-tetrakis (4-aminophenyl) porphyrin (TAPP), and Fe3+ for photodynamic therapy (PDT)-enhanced ferroptosis in cancer treatment. PAF exhibited a size of 135 nm and a TAPP and Fe3+ loading content of 6.99 and 0.77%, respectively. The singlet oxygen (1O2) generation capacity of TAPP can be activated and significantly enhanced at acidic pH (4.5–5.0). Besides, the enhanced near-infrared absorption of TAPP at acidic pH enabled a further increase in 1O2 generation capability by a near-infrared laser (760 nm). The polysaccharide-based polymer carrier offers excellent biocompatibility, and PAF displayed a proliferative effect in both normal (L929) and cancer (B16) cells. However, upon light irradiation, PAF exhibited high toxicity to B16 melanoma cells by intracellular reactive oxygen species elevation, glutathione depletion, and lipid peroxidation. PAF displayed a much better anticancer effect than the nanocomplex containing Fe3+ or TAPP alone, indicating the PDT-enhanced ferroptosis in PAF. This study suggested that PDT-enhanced ferroptosis could be a facile and robust strategy of nanotherapeutics with high potency, tumor selectivity, and excellent biocompatibility.
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