ROS-responsive nanocarrier for oral delivery of monascin and enhanced alleviation of oxidative stress.

Oxidative stress, caused by excessive production of reactive oxygen species (ROS), plays a crucial role in the occurrence and development of various diseases. Monascin can scavenge ROS and alleviate oxidative stress but with a low fermentation rate and bioavailability. Here, we optimized the fermentation process to increase the production of monascin (508.6 U/mL), and then systematically characterized its structure via HPLC, HPLC-MS, ¹H NMR, and ¹³C NMR. Additionally, we innovatively modified carboxymethylcellulose sodium with selenium (CMC-Se) to encapsulate monascin (monascin@CMC-Se), which can sensitively respond to ROS and release monascin to effectively scavenge excessive ROS. Besides, the monascin@CMC-Se can significantly increase the bioaccessibility of monascin and alleviate cellular oxidative stress by enhancing its cellular uptake rate. Collectively, our work provides proof-of-principle evidence that the CMC-Se can precise delivery of monascin to an oxidatively stressed environment with high resistance to gastric fluids, laying a foundation to overcome inflammation-related diseases in the colon.