Excessive
reactive oxygen species (ROS) is a hallmark of both the
onset and progression of inflammatory bowel disease (IBD), where a
continuous cycle of ROS and inflammation drives the progression of
diseases. The design of oral antioxidant nanoenzymes for scavenging
ROS has emerged as a promising strategy to intervene in IBD. However,
the practical application of these nanoenzymes is limited due to their
single catalytical property and significantly impacted by substantial
leakage in the upper gastrointestinal tract. This study introduces
a novel oral delivery system, SP@CS-SeNPs, combining natural microalgae Spirulina platensis (SP), which possesses superoxide
dismutase (SOD)-like activity, with chitosan-functionalized selenium
nanoparticles (CS-SeNPs) that exhibit catalase-like activity. The
SP@CS-SeNPs system leverages the dual catalytic capabilities of these
components to initiate a cascade reaction that first converts superoxide
anion radicals (O2
•–) into hydrogen
peroxide (H2O2), and then catalyzes the decomposition
of H2O2 into water and oxygen. This system not
only utilizes the resistance of the microalgae carrier to gastric
acid and its efficient capture by intestinal villi, thereby enhancing
intestinal distribution and retention but also demonstrates significant
anti-inflammatory effects and effective repair of the damaged intestinal
barrier in a colitis mice model. These results demonstrate that this
oral delivery system successfully combines the features of microalgae
and nanozymes, exhibits excellent biocompatibility, and offers a novel
approach for antioxidant nanozyme intervention in IBD.