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.

In vivo inducing collagen regeneration of biodegradable polymer microspheres

Biodegradable polymer particles have been used as dermal fillers for pre-clinical and clinical trials.The impact of material properties of polymers is very important to develop products for aesthetic medicine such as dermal fillers.Herein,eight biodegradable polymers with different molecular weights,chemical compositions or hydrophilic-hydrophobic properties were prepared and characterized for systematical study for aesthetic medicine applications.Polymer microspheres with 20-100 lmwere prepared.The in vitro degradation study showed that poly(L-lactic-co-glycolic acid)75/25 microspheres degraded the fastest,whereas poly(L-lactic acid)(PLLA)microspheres with intrinsic viscosity of 6.89([g]¼6.89)with the highest molecular weight showed the slowest degradation rate.After these microspheres were fabricated dermal fillers according to the formula of SculptraVR,they were injected subcutaneously into the back skin of rabbits.In vivo results demonstrated that the degradation rate of microspheres strongly correlated with the foreign body reaction and collagen regeneration was induced by microspheres.The microspheres with faster degradation rate induced inflammatory response and the collagen regeneration maintained in shorter time.PLLA([g]¼3.80)microsphere with a moderate molecular weight and degradation rate could strongly regenerate Type I and III collagen to maintain a long-term aesthetic medicine effect.These properties of size,morphology and degradation behavior would influence the foreign body reaction and collagen regeneration.