Oral Delivery of Transformable Bilirubin Self-Assembled System for Targeted Therapy of Colitis

Inflammation-targeted delivery of probiotics for alleviation of colitis and associated cognitive disorders through improved vitality and colonization

Oral probiotic biotherapies hold significant promise for addressing intestinal inflammatory disorders. Nonetheless, due to the challenging pathological microenvironment of the gastrointestinal tract, it is difficult to achieve deliver probiotics in an inflammation-targeted manner while improving their intestinal colonization and minimizing the impact of gastrointestinal environment on their vitality. To address this, an innovative probiotics oral delivery system (EcN-Apt@HG) against ulcerative colitis (UC) was developed by conjugating IL-6 aptamer to the surface of EcN and subsequently encapsulating the probiotics in a hydrogel consisting of aldehyde-functionalized chondroitin sulfate (CS) and Poly(amidoamine) (PAMAM). As expected, the encapsulated EcN demonstrated resistance to gastrointestinal conditions, and the colonization duration of probiotics in the colon was enhanced via the preferential adhesion effect of IL-6 aptamer on the inflammatory site. The EcN-Apt@HG system restored the damaged mucosal layer, suppressed hyperactive immune responses, and reshaped the dysbiosis of intestinal microflora, thereby synergistically alleviating dextran sulfate sodium (DSS)-induced colitis. Notably, EcN-Apt@HG significantly alleviated depression-like behaviors and cognitive impairment in colitis mice through gut-brain axis interaction. This approach provides a simple and promising strategy for inflammation-targeted delivery of probiotics to the intestine and shows great potential for UC therapy and associated cognitive disorders.

Folic acid-based hydrogels co-assembled with protocatechuic acid for enhanced treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) presents a significant therapeutic challenge due to the need for oral drug delivery systems that withstand acidic environment of stomach while effectively targeting intestinal inflammation. To address this issue, we created a novel hydrogel system based on a folic acid (FA)-dopamine (DA) conjugate, co-assembled with protocatechuic acid (PCA), to form F-DP hydrogels. These hydrogels demonstrated robust anti-gastric acid, mucosal adhesive, and injectable properties, enhancing their efficacy for targeted delivery. In DSS-induced colitis mouse models, treatment with F-DP hydrogels resulted in significant therapeutic improvements, including increased body weight, reduced disease activity index (DAI), and maintained colon length. Biochemical assays revealed that F-DP hydrogels significantly enhanced antioxidant enzyme activities (GSH and SOD) and reduced oxidative stress markers (NO and MDA). Histological assessments confirmed effective repair of the colonic mucosal barrier, restoration of tight junction protein ZO-1, and reduction of inflammatory lesions. Furthermore, immunofluorescence staining indicated that F-DP hydrogels facilitated macrophages polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, thereby reducing inflammation and promoting tissue repair. Our study demonstrates that F-DP hydrogels show significant potential for improving IBD treatment through enhanced gastric resistance, intestinal adhesion, and synergistic anti-inflammatory effects, warranting further investigation for clinical applications.

Formononetin alleviates ulcerative colitis via reshaping the balance of M1/M2 macrophage polarization in a gut microbiota-dependent manner

BACKGROUND

Ulcerative colitis (UC), a type of inflammatory bowel disease, presents substantial challenges in clinical treatment due to the limitations of current medications. Formononetin (FN), a naturally compound with widespread availability, exhibits anti-inflammatory, antioxidant, and immunomodulatory properties.

PURPOSE

This study aimed to investigate the efficacy of FN against UC and its potential regulatory mechanism.

METHODS

Here, dextran sulfate sodium (DSS) was employed to replicate experimental colitis in mice with concomitant FN treatment. The distribution and localisation of CD68 and F4/80 macrophages in colonic tissues were visualized by immunofluorescence, their chemokine and inflammatory cytokine concentrations were determined by ELISA, and macrophages and M1/M2 subpopulations were determined by flow cytometry. Additionally, 16 s rRNA and LC-MS techniques were used to detect the colonic intestinal microbiota and metabolite profiles, respectively. Correlation analyses was performed to clarify the interactions between differential bacteria, metabolites and M1/M2 macrophages, and pseudo sterile mice were constructed by depletion of gut flora with quadruple antibiotics, followed by faecal microbial transplantation to evaluate its effects on colitis and M1/M2 macrophage polarisation.

RESULTS

FN dose-dependently alleviated clinical symptoms and inflammatory injury in colonic tissues of colitis mice, with its high-dose efficacy comparable to that of 5-ASA. Concurrently, FN not only inhibited inflammatory infiltration of macrophages and their M1/M2 polarisation balance in colitis mice, but also improved the composition of colonic microbiota and metabolite profiles. However, FN lost its protective effects against DSS-induced colitis and failed to restore the equilibrium of M1/M2 macrophage differentiation following intestinal flora depletion through quadruple antibiotic treatment. Importantly, fecal microbiota transplantation from FN-treated mice restored FN's protective effects against DSS-induced colitis and reestablished its regulatory role in M1/M2 macrophage polarization.

CONCLUSION

Collectively, FN ameliorated UC through modulating the balance of M1/M2 macrophage polarization in a gut microbiota-dependent manner.

Oral food-derived whey protein isolate-Tremella fuciformis polysaccharides pickering emulsions with adhesive ability to delivery magnolol for targeted treatment of ulcerative colitis

Magnolol (Mag) is a promising natural compound with therapeutic potential for ulcerative colitis (UC). Here we designed and fabricated an oral food-grade whey protein isolate-Tremella fuciformis polysaccharides (WPI-TFPS) stabilized pickering emulsions to encapsulate Mag (Mag-WPI-TFPS) for targeted treatment of UC. With the assistance of the WPI-TFPS, pickering emulsions were well encapsulated and formed stable microparticles with a particle size of approximately 9.49 ± 0.047 μm, a 93.63 ± 0.21 % encapsulation efficiency and a loading efficiency of 21.53 ± 0.01 %. In vitro, the formulation exhibited sustained-release properties in simulated colon fluid with a cumulative release rate of 60.78 % at 48 h. In vivo, the Mag-WPI-TFPS specifically accumulated in the colon tissue for 24 h with stronger fluorescence intensity, which demonstrated that TFPS and WPI had a good adherence ability to inflamed mucosa by electrostatic attraction and ligand-receptor interactions. As expected, compared with Free-Mag, the oral administration of Mag-WPI-TFPS remarkably alleviated the symptoms of UC and protected the colon tissue in DSS-induced UC mice. More importantly, WPI-TFPS enhanced gut microbiota balance by increasing the diversity and relative abundances of Lactobacillaceae and Firmicutes. Overall, this study presents a convenient, eco-friendly, food-derived oral formulation with potential as a dietary supplement for targeted UC treatment.

Berberine and magnolol exert cooperative effects on ulcerative colitis in mice by self-assembling into carrier-free nanostructures

The risk of ulcerative colitis (UC) is increasing worldwide with limited success using classical drugs, which has underscored the development of novel agents. Recently, carrier-free molecular assembly has been proven to be an effective drug delivery system, but it has yet to be examined for UC drug development using phytochemicals. Based on traditional Chinese medicine compatibility and potential medicinal uses, a pair of natural compounds, berberine (BBR) and magnolol (MAG), were found to self-assemble into nanostructures in aqueous solutions. Spectral analysis revealed that the assembly mechanisms of BBR and MAG were mediated through charge interactions and π-π stacking. Pharmacokinetic studies and animal imaging showed that BBR-MAG self-assembly (BM) effectively promoted the oral bioavailability and biodistribution of BBR in the colon. BM exhibited superior effects in regulating inflammatory factors, maintaining colon barrier integrity, and regulating gut microbiota in a dextran sulfate sodium salt-induced colitis mouse model. Additionally, no apparent signs of toxicity were observed, suggesting that BM has a favorable safety profile. This study presents a new strategy for UC management and highlights the cooperative effects of combined phytochemicals.

Enzyme/ROS dual-sensitive nanoplatform with on-demand Celastrol release capacity for enhanced ulcerative colitis therapy by ROS scavenging, microbiota rebalancing, inflammation alleviating

BACKGROUND

The oral administration of drugs for treating ulcerative colitis (UC) is hindered by several factors, including inadequate gastrointestinal stability, insufficient accumulation in colonic lesions, and uncontrolled drug release.

METHODS

A multiple sensitive nano-delivery system comprising β-cyclodextrin (CD) and 4-(hydroxymethyl)phenylboronic acid (PAPE) with enzyme/reactive oxygen species (ROS) sensitivity was developed to load celastrol (Cel) as a comprehensive treatment for UC.

RESULTS

Owing to the positive charge in the site of inflamed colonic mucosa, the negatively charged nanomedicine (Cel/NPs) could efficiently accumulate. Expectedly, Cel/NPs showed excellent localization ability to colon in vitro and in vivo tests. The elevated concentration of ROS and intestinal enzymes in the colon microenvironment quickly break the CD, resulting in Cel release partially to rebalance microbiota and recover the intestinal barrier. The accompanying cellular internalization of residual Cel/NPs, along with the high concentration of cellular ROS to trigger Cel burst release, could decrease the expression of inflammatory cytokines, inhibit colonic cell apoptosis, promote the macrophage polarization, scavenge ROS, and regulate the TLR4/NF-κB signaling pathway, which certified that Cel/NPs possessed a notably anti-UC therapy outcome.

CONCLUSIONS

We provide a promising strategy for addressing UC symptoms via an enzyme/ROS-sensitive oral platform capable of releasing drugs on demand.

Reactive oxygen species (ROS) scavenging biomaterials for anti-inflammatory diseases: from mechanism to therapy

Inflammation is a fundamental defensive response to harmful stimuli, but the overactivation of inflammatory responses is associated with most human diseases. Reactive oxygen species (ROS) are a class of chemicals that are generated after the incomplete reduction of molecular oxygen. At moderate levels, ROS function as critical signaling molecules in the modulation of various physiological functions, including inflammatory responses. However, at excessive levels, ROS exert toxic effects and directly oxidize biological macromolecules, such as proteins, nucleic acids and lipids, further exacerbating the development of inflammatory responses and causing various inflammatory diseases. Therefore, designing and manufacturing biomaterials that scavenge ROS has emerged an important approach for restoring ROS homeostasis, limiting inflammatory responses and protecting the host against damage. This review systematically outlines the dynamic balance of ROS production and clearance under physiological conditions. We focus on the mechanisms by which ROS regulate cell signaling proteins and how these cell signaling proteins further affect inflammation. Furthermore, we discuss the use of potential and currently available-biomaterials that scavenge ROS, including agents that were engineered to reduce ROS levels by blocking ROS generation, directly chemically reacting with ROS, or catalytically accelerating ROS clearance, in the treatment of inflammatory diseases. Finally, we evaluate the challenges and prospects for the controlled production and material design of ROS scavenging biomaterials.