An olsalazine nanoneedle-embedded inulin hydrogel reshapes intestinal homeostasis in inflammatory bowel disease

Inflammatory bowel disease(IBD)is a chronic and refractory condition characterized by disrupted epithelial barrier,dysregulated immune balance,and altered gut microbiota.Nano-enabled interventions for restoring gut homeostasis have the potential to alleviate inflammation in IBD.Herein,we developed a combination of olsalazine(Olsa)-based nanoneedles and microbiota-regulating inulin gel to reshape intestinal homeostasis and relieve inflammation.The Olsa-derived nanoneedles exhibited reactive oxygen species scavenging ability and anti-inflammatory effects in lipopolysaccharide-simulated macrophages.The composite of nanoneedles and inulin gel(Cu2(Olsa)/Gel)displayed a macroporous structure,improved bio-adhesion,and enhanced colon retention after oral administration.Mechanistically,the composite effectively downregulated pro-inflammatory cytokine levels and promoted epithelial barrier repair through anti-inflammatory and antioxidant therapies,resulting in significant alleviation of colitis in three animal models of IBD.Furthermore,analysis of gut microbiota revealed that Cu2(Olsa)/Gel treatment increased the diversity of intestinal microflora and decreased the relative abundance of pathogenic bacteria such as Proteobacteria.Overall,this study provides a self-delivering nanodrug and dietary fiber hydrogel composite for IBD therapy,offering an efficient approach to restore intestinal homeostasis.

A Mg^(2+)/polydopamine composite hydrogel for the acceleration of infected wound healing

Bacterial infection is a vital factor to delay the wound healing process.The antibiotics abuse leads to drug resistance of some pathogenic bacteria.Non-antibiotic-dependent multifunctional biomaterials with accelerated wound healing performance are urgently desired.Herein,we reported a composite antibacterial hydrogel PDA-PAM/Mg^(2+)that shows excellent self-healing and tissue adhesive property,and photothermal antibacterial functions for accelerating wound healing.The gel was composed of polyacrylamide(PAM),polydopamine(PDA),and magnesium(Mg^(2+))and prepared via a two-step procedure:an alkali-induced dopamine pre-polymerization and followed radical polymerization process.The composite gel shows excellent tissue adhesiveness and Mg^(2+)-synergized photothermal antibacterial activity,inducing a survival rate of 5.29% for S.aureus and 7.06%for E.coli after near infrared light irradiation.The composite hydrogel further demonstrated efficient bacteria inhibition,enhanced wound healing and collagen deposition in a full-thickness skin defect rat model.Together,the PDA-PAM/Mg^(2+) hydrogel presents an excellent wound dressing with excellent tissue adhesion,wound healing,and antibacterial functions.