Inflammatory bowel disease (IBD) is an idiopathic chronic inflammatory bowel disease characterized by inflammation, intestinal barrier injury, and imbalance of gut microbiota. Excess accumulation of reactive oxygen species (ROS) is closely correlated with the development and reoccurrence of IBD. Previous researches demonstrate that procyanidin, as a natural antioxidant, exhibits strong ability of eliminating ROS, thus showing good therapeutic effects in the inflammation-related diseases. Non-etheless, its poor stability and solubility always limits the therapeutic outcomes. Here, we typically designed an antioxidant coordination polymer nanoparticle using the engineering of procyanidin (Pc) and free iron (Fe), named Pc-Fe nanozyme, for effectively scavenging ROS and further inhibiting inflammation while altering the gut microbiome for the treatment of colitis. Furthermore, in vitro experiments uncover that Pc-Fe nanoparticles exert strong multi biomimic activities, including peroxidase, and glutathione peroxidase, for the scavenging of ROS and protecting cells from oxidative injury. In addition, the colon accumulation of Pc-Fe nanozyme effectively protects the intestinal mucosa from oxidative damage while significantly downregulates pro-inflammatory factors, repairs the intestinal barriers and alternates gut microbiome after orally administrated in sodium dextran sulfate (DSS) induced colitis mice. The results collectively illustrate that the multienzyme mimicking Pc-Fe nanozyme owns high potential for treating IBD through scavenging ROS, inhibiting inflammation, repairing gut barriers and alternating gut microbiome, which further promising its clinical translation on IBD treatment and other ROS induced intestinal diseases.

Emerging evidence implicates gut microbiota in the pathogenesis of obesity-related depression (OD); however, the underlying molecular mechanisms remain inadequately explored. This study compared the microbial and transcriptional profiles between patients with OD and healthy individuals. The results revealed an enrichment of Anaerotruncus colihominis (A. colihominis) and glutamate metabolism-related genes in the OD group. Fecal microbiota transplantation (FMT) from patients with OD induced weight gain, compromised barrier function, and intensified depression-like behaviors in high-fat diet (HFD) mice. Microbial analysis in the mice feces corroborated the clinical findings. Single-cell RNA sequencing highlighted the pivotal role of the Efnb2-Ephb2 interaction in cell communication among colon epithelial and hippocampal neuron subtypes in OD mice. Notably, A. colihominis correlated with glutamate levels in the OD mice and patients. It produced glutamate through a glutamic acid metabolism-related DNA sequence, verified in an engineered Escherichia coli MG1655 strain. Both A. colihominis and glutamate reduced barrier proteins in colon epithelial cells and modulated cognitive proteins in neurons. Finally, A. colihominis treatment induced the Efnb2-Ephb2 interaction, exacerbating depression-like behaviors in germ-free HFD mice. Collectively, these findings reveal that A. colihominis and glutamate are potential intervention targets for OD treatment.

Recent advancements in sonodynamic therapy (SDT) for cancer treatment have highlighted the potential of enhancing reactive oxygen species (ROS) generation and improving therapeutic outcomes. This study introduces zinc oxide (ZnO) nanorods (NRs) in situ loaded with silver nanoparticles (ZnO@Ag NRs), designed to optimize ROS production under ultrasound irradiation and offer significant advantages in tumor specificity and biosafety. The transmission electron microscopy and elemental mapping confirmed the consistent size and monodispersed Ag nanoparticle for ZnO@Ag NR. Sonodynamic properties showed that ZnO@Ag NRs produce higher singlet oxygen and hydroxyl radicals under ultrasound. In vitro studies demonstrated excellent biocompatibility and enhanced cell-killing effects of ZnO@Ag NRs on CT-26 cells, while in vivo results confirmed its superior anti-tumor efficacy and biosafety. Furthermore, the ZnO@Ag NRs’ antibacterial properties were also confirmed, suggesting additional benefits in treating cancers associated with bacterial infections. Collectively, these findings establish ZnO@Ag NRs as a potent and safe agent for ultrasound-driven cancer therapy.