Construction of marine biomaterial fucoidan nanoscavengers and their application in colitis treatment

Ulcerative colitis (UC) is a chronic inflammatory bowel disease that primarily affects the colon and rectum and is characterized by diffuse, superficial inflammation of the colonic mucosa. The excessive production of reactive oxygen species (ROS) plays a pivotal role in immune dysregulation and the pathogenesis of UC. However, current treatment options are limited by poor absorption, rapid metabolism, and systemic side effects due to the lack of targeted delivery. Therefore, there is an urgent need for therapies capable of specifically scavenging ROS. In this study, we developed a ROS-responsive nanoscavenger system, Fucoidan-TK-Resveratrol@Curcumin (FTR@Cur), based on the marine-derived polysaccharide fucoidan, and loaded with the natural compound curcumin (Cur) for the treatment of UC. The nanoscavenger was constructed using fucoidan (Fuc) as the hydrophilic backbone, while resveratrol (Res) was conjugated via a ROS-sensitive thioketal (TK) linker, enabling targeted ROS clearance. The resulting FTR@Cur nanoparticles had a mean particle size of 92.17 nm, a zeta potential of -22.2 mV, and an encapsulation efficiency and drug loading of 69.0% and 5.5%. FTR@Cur exhibited excellent ROS-scavenging ability and biocompatibility, effectively modulating the inflammatory and immune microenvironment in the colon. This system enhanced colonic barrier function, reduced inflammation, and offers a promising therapeutic strategy for UC.