Oral antimicrobial peptide-EGCG nanomedicines for synergistic treatment of ulcerative colitis

Oral colon-targeted delivery of recombinant human MANF for alleviation of ulcerative colitis

Midbrain astrocyte-derived neurotrophic factor (MANF) is a secreted protein induced by endoplasmic reticulum stress. Previous studies have indicated that intravenous administration of 1 mg/kg/day recombinant human MANF protein with His tag (His-MANF) for 3 days can ameliorate acute ulcerative colitis in mice. However, long-term intravenous therapy has many disadvantages. In this paper, His-MANF protein was successfully encapsulated into alginate and hyaluronic acid hybrid hydrogel microcapsules in one step using the gas shear method and then coated by Eudragit S100 to construct an oral colon-targeted delivery system (MSH@E). The MSH@E microcapsules exhibited controlled and sustained release behavior and colon-targeting properties. Both fluorescent imaging and immunohistochemistry staining results showed that His-MANF protein could accumulate in the colitis colon for a longer residence time after oral delivery. In vivo studies demonstrated that oral administration of MSH@E microcapsules could alleviate DSS-induced colitis in mice without systemic toxicity. Importantly, even if the oral His-MANF dose was half of the intravenous His-MANF dose, oral delivery was still much more effective than intravenous injection, suggesting the development of the oral colon-targeted delivery system (MSH@E) has great significance and makes a breakthrough from intravenous to oral administration for His-MANF treatment of ulcerative colitis (UC).

Precisely edited gut microbiota by tungsten-doped Prussian blue nanoparticles for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterized by recurring gastrointestinal inflammation, accompanied by a significant rise in global prevalence and disease severity. The overaccumulation of reactive oxygen and nitrogen species (RONS) in the intestinal environment disrupts redox homeostasis and drives pathological overgrowth of Escherichia coli, which are central to IBD pathogenesis. Herein, we designed a multifunctional nanozyme (W-PB) to enable sustained and targeted regulation of intestinal homeostasis through dual mechanisms: specific inhibition of E. coli overgrowth during colitis and efficient RONS clearance. To ensure colon-specific delivery, W-PB was encapsulated in an electrostatically crosslinked hydrogel composed of alginate and chitosan. This formulation protects W-PB from degradation in harsh gastrointestinal conditions and releases the nanoparticles selectively under weakly alkaline intestinal pH. The released tungsten ions suppress E. coli growth via competitive displacement of molybdenum in the molybdopterin cofactor, while W-PB simultaneously neutralizes excess RONS to shield intestinal cells from oxidative damage. In DSS-induced colitis models, the W-PB gel demonstrated significant therapeutic efficacy, achieved through intestinal microbiota remodeling and oxidative stress mitigation.

The stomach, small intestine, and colon-specific gastrointestinal tract delivery systems for bioactive nutrients

Oral administration is a convenient way to deliver bioactive nutrients. However, the complex and dynamic environment of the gastrointestinal (GI) tract poses distinct challenges. These include the acidic environment of the stomach, limited transport across the GI mucosa, and the risk of enzymatic degradation, all of which can compromise the nutritional effectiveness of orally delivered nutrients. In response to these challenges, various GI tract delivery systems have been developed to target specific regions, such as the stomach, small intestine, or colon, to precisely control the release of bioactive nutrients and enhance their health-promoting benefits. This review critically examines the principles underlying stomach-, small intestine-, and colon-targeted delivery systems, highlighting the selection of appropriate wall materials and the interactions between delivery systems and the mucosal epithelial barrier. Moreover, we describe relevant biological models and quantitative analyses to measure these interactions. In particular, we emphasize the significant advantages offered by colon-targeted delivery systems in maintaining a healthy colonic microenvironment. This review aims to inspire novel concepts and stimulate further research into GI tract delivery systems, offering promising avenues for maximizing the therapeutic effects of bioactive nutrients in practical applications.

The emerging role of intestinal stem cells in ulcerative colitis

Ulcerative colitis (UC) is a chronic idiopathic inflammatory disease affecting the colon and rectum. Characterized by recurrent attacks, UC is often resistant to traditional anti-inflammatory therapies, imposing significant physiological, psychological, and economic burdens on patients. In light of these challenges, innovative targeted therapies have become a new expectation for patients with UC. A crucial pathological feature of UC is the impairment of the intestinal mucosal barrier, which underlies aberrant immune responses and inflammation. Intestinal stem cells (ISCs), which differentiate into intestinal epithelial cells, play a central role in maintaining this barrier. Growing studies have proved that regulating the regeneration and differentiation of ISC is a promising approach to treating UC. Despite this progress, there is a dearth of comprehensive articles describing the role of ISCs in UC. This review focuses on the importance of ISCs in maintaining the intestinal mucosal barrier in UC and discusses the latest findings on ISC functions, markers, and their regulatory mechanisms. Key pathways involved in ISC regulation, including the Wnt, Notch, Hedgehog (HH), Hippo/Yap, and autophagy pathways, are explored in detail. Additionally, this review examines recent advances in ISC-targeted therapies for UC, such as natural or synthetic compounds, microbial preparations, traditional Chinese medicine (TCM) extracts and compounds, and transplantation therapy. This review aims to offer novel therapeutic insights and strategies for patients who have long struggled with UC.

Larimichthys crocea isinglass polysaccharide attenuates DSS-induced colitis via gut microbiota regulation and NF-κB signaling inhibition

This study aimed to investigate the therapeutic efficacy of Larimichthys Crocea Isinglass polysaccharide (CIP) in ameliorating DSS-induced colitis. CIP, a complex polysaccharide composed of six monosaccharides with a molecular weight of 3.97 kDa. Specifically, CIP treatment mitigated weight loss and histopathological damage in the colon, increased colon length, and by inhibiting the TLR4/MyD88/NF-κB pathway significantly downregulated the secretion levels of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, while simultaneously upregulating the anti-inflammatory cytokine IL-10 and inhibition of the oxidative stress-related enzyme inducible nitric oxide synthase (iNOS). Additionally, CIP treatment enhanced intestinal barrier function by increasing the expression of intestinal tight junction proteins (TJs) and MUC2, and it promoted the production of short-chain fatty acids (SCFAs). Concurrently, CIP modulated the composition of the intestinal microbiota, inhibiting the proliferation of potentially harmful bacteria such as Bacteroidota and Campylobacter. Taken together, these findings suggest that CIP exhibits promising attributes as a functional food constituent, with a particular efficacy in modulating and maintaining intestinal health.

Compliant immune response of silk-based biomaterials broadens application in wound treatment

The unique properties of sericin and silk fibroin (SF) favor their widespread application in biopharmaceuticals, particularly in wound treatment and bone repair. The immune response directly influences wound healing cycle, and the extensive immunomodulatory functions of silk-based nanoparticles and hydrogels have attracted wide attention. However, different silk-processing methods may trigger intense immune system resistance after implantation into the body. In this review, we elaborate on the inflammation and immune responses caused by the implantation of sericin and SF and also explore their anti-inflammatory properties and immune regulatory functions. More importantly, we describe the latest research progress in enhancing the immunotherapeutic and anti-inflammatory effects of composite materials prepared from silk from a mechanistic perspective. This review will provide a useful reference for using the correct processes to exploit silk-based biomaterials in different wound treatments.

Protective Role of Nano-encapsulated Bifidobacterium breve, Bacilllus coagulans, and Lactobacillus plantarum in Colitis Model: Insights Toward Propagation of Short-Chain Fatty Acids and Reduction of Exaggerated Inflammatory and Oxidative Response

Irritable bowel disease (IBD), also known as ulcerative colitis and Crohn's disease, is a chronic inflammatory disorder affecting millions of people worldwide. Herein, nano-encapsulated multi-strain probiotics formulation, comprising Bifidobacterium breve DSM24732 and B. coagulans SANK 70258 and L. plantarum DSM24730 (BBLNPs) is used as an effective intervention technique for attenuating IBD through gut microenvironment regulation. The efficacy of the prophylactic role of BBLNPs in alleviating injury induced by dextran sulfate sodium (DSS) was evaluated by assessing oxidative and inflammatory responses, levels of short-chain fatty acids (SCFAs) and their regulation on GPR41/43 pathway, expression of genes related to tight-junctions and autophagy, immunohistochemistry of IL1β and GPR43, and histological examination of inflamed colonic tissue. The severity of clinical signs and paracellular permeability to FITC (fluorescein isothiocyanate)-labeled dextran was significantly decreased after BBLNP treatment. Reduction of oxidative stress-associated biomarkers (MDA, ROS, and H2O2) and acceleration of antioxidant enzyme activities (SOD, CAT, and GSH-Px) were noted in the BBLNP-treated group. Subsiding of inflammatory markers (TNF-α, IL-18, IL-6, TRL-4, CD-8, NLRP3, and caspase 1) and upregulation of tight-junction-related genes (occludin and JAM) was detected in BBLNPs. Administration of BBLNPs remarkably resulted in a higher level of SCFAs which parrel with colonic upregulation of GPR41 and GPR43 expression compared to DSS-treated rats. Notable modulation of autophagy-related genes (p62, mTOR, LC3, and Beclin-1) was identified post BBLNP treatment. The mRNA expressions of p62 and mTOR were significantly downregulated, while LC3 and Beclin-1 were upregulated after prophylactic treatment with BBLNPs. Immune-stained labeled cells showed lower expression of IL-1β and higher expression levels of GPR43 in BBLNPs compared to the DSS-induced group. The intestinal damage caused by DSSwas effectively mitigated by oral BBLNP treatment, as supported by the restoration of healthy colonic tissue architecture. The findings suggest that BBLNPs have a promising avenue in the remission of IBD by modulating inflammation, oxidative stress, microbial metabolites such as SCFAs, and autophagy.

Oral chitosan-cyclodextrin "shell-core" nanoparticles co-loaded Rhein and chlorogenic acid for ulcerative colitis treatment

The food-derived ingredients Rhein (RH) and chlorogenic acid (CGA) have DEMONSTRATED a potential synergistic effect in the treatment of ulcerative colitis (UC) through their anti-inflammatory and antioxidant properties. However, the oral co-delivery of RH and CGA faces challenges such as differences in hydrophilicity and hydrophobicity, gastrointestinal instability, and inadequate colonic targeting. To address these issues, shell-core nanoparticles were developed for the co-encapsulation of RH and CGA (CP@CGA-FA/TA@RH NPs). These nanoparticles utilize cyclodextrin-based polymers and folate-amantadine polymers to form a supramolecular core that targets macrophages for anti-inflammatory action with RH, while chitosan cross-link to CGA in the outer shell provides microenvironment-sensitive antioxidant release. The results indicate that CP@CGA-FA/TA@RH NPs could effectively inhibit the classical TLR4/MyD88/NF-κB-mediated anti-inflammatory pathway and activate the Nrf2/HO-1-mediated antioxidant pathway, offering a novel approach to UC treatment. Q-value analysis confirms the substantial co-medication effect between RH and CGA. This study is the first to develop a nano-system combining two food-derived ingredients for the integrated treatment of UC.

Solid Self-Microemulsifying Drug Delivery System for Improved Oral Bioavailability of Relugolix: Preparation and Evaluation

Purpose

To improve the oral absorption of relugolix (RLGL), which has low oral bioavailability due to its low solubility and being a substrate of P-glycoprotein (P-gp). A solid self-microemulsifying drug delivery system of relugolix (RLGL-S-SMEDDS) was prepared and evaluated in vitro and in vivo.

Methods

The composition of the solid self-microemulsifying drug delivery system (S-SMEDDS) was selected by solubility study and pseudo-ternary phase diagram, and further optimized by Design-Expert optimization design. The optimized RLGL-S-SMEDDS were evaluated in terms of particle size, zeta potential, morphology analysis, thermodynamic stability, drug release, flow properties, transporter pathways in Caco-2 cells, the influence of excipients on the intestinal transporters, transport within Caco-2 cell monolayers and transport in lymphocyte. In vivo pharmacokinetic study and toxicological study were also conducted.

Results

The optimum formulation for self-microemulsifying drug delivery system (SMEDDS) consists of Ethyl Oleate (26% of the weight), Solutol HS15 (49% of the weight), Transcutol HP (25% of the weight) and loaded relugolix (4.8 mg/g). The S-SMEDDS was then formed by adsorbing 2.4 g of SMEDDS onto 1 g of hydrophilic-200 silica. In phosphate buffered saline (PBS) (pH 6.8) release medium containing 1% tween 80, the vitro release studies showed 86% cumulative drug release for RLGL-S-SMEDDS and 3.6% cumulative drug release for RLGL suspensions. In vitro cellular uptake experiments revealed that the uptake of RLGL-S-SMEDDS by Caco-2 cells was three times higher than that of free RLGL, and that S-SMEDDS can enhance the drug absorption through lymphatic absorption and inhibition of intestinal transporter. In vivo pharmacokinetic evaluation demonstrated that the oral bioavailability of RLGL-S-SMEDDS was 1.9 times higher than that of RLGL-suspensions. There was no apparent cardiac, hepatic, splenic, pulmonary or renal toxicity on the surface discovered by pathological analysis after oral administration.

Conclusion

It is evident that S-SMEDDS may be a safe and effective method to improve oral absorption of drugs with low oral bioavailability.

Nanotherapeutics-mediated restoration of pancreatic homeostasis and intestinal barrier for the treatment of severe acute pancreatitis

Severe acute pancreatitis (SAP) is an inflammatory disease of the pancreas accompanied with intestinal injury, and effective therapeutic modalities are still highly lacking. Herein, a facile and effective nanotherapeutics (pHA@IBNCs) is developed to alleviate pancreatic inflammation and restore intestinal barrier for SAP treatment. Epigallocatechin gallate (EGCG, an anti-oxidant), interleukin-22 (IL-22, an anti-inflammatory and epithelial barrier-protecting cytokine), and bovine serum albumin (a framework protein), are assembled via non-covalent interactions to form nanocomplexes (IBNCs). Then, phenylboronic acid-modified hyaluronic acid (pHA) is synthesized and coated onto IBNCs via formation of the reversible boronate ester bonds to obtain pHA@IBNCs. Upon intravenous injection, pHA@IBNCs could efficiently accumulate at the lesion sites of sodium taurocholate (STC)-induced SAP mice, based on their prolonged blood circulation time and pHA-mediated targeting of activated intestinal epithelial cells and macrophages. Inside the inflammatory microenvironment, over-produced reactive oxygen species (ROS) trigger the shedding of the pHA layer and release of the drug payloads. Thereby, EGCG cooperates with IL-22 to attenuate pancreatitis and restore the intestinal barrier by scavenging ROS, suppressing pro-inflammatory cytokines secretion, and promoting the repair of intestinal epithelia. Such a nano-therapeutic approach targeting multiple pathological events may serve as a promising paradigm for the effective management of SAP.

Hyaluronan Scaffold Decorated with Bifunctional Peptide Promotes Wound Healing via Antibacterial and Anti-Inflammatory

The invasion of bacteria and inflammation impeded infected wounds heal. Here, a hyaluronan-based scaffold (HAG-g-C) was designed by cross-linking with gallic acid-modified gelatin to provide a protein microenvironment and decorated with cathelicidin-BF (CBF), a natural antimicrobial peptide, to remove bacterial infections and reverse the inflammatory environment. In vitro, HAG-g-C presented an antibacterial effect on Staphylococcus aureus and Escherichia coli. Meanwhile, it could drive the phenotypic switch of macrophage from M1 to M2 to accelerate tissue remodeling. In a mouse model of S. aureus-infected total skin defects, HAG-g-C inhibited the process of infection at the beginning of the wound and then regulated the M1 macrophage transformed to M2 phenotype on day 12. In addition, HAG-g-C induced collagen deposition, and reduced the expression of TNF-α, thereby significantly accelerating the reconstruction of infected wounds.

Formulation, characterization, and evaluation of curcumin-loaded ginger-derived nanovesicles for anti-colitis activity

Plant-derived nanovesicles have gained attention given their similarity to mammalian exosomes and advantages such as low cost, sustainability, and tissue targeting. Thus, they hold promise for disease treatment and drug delivery. In this study, we proposed a time-efficient method, PEG 8000 combined with sucrose density gradient centrifugation to prepare ginger-derived nanovesicles (GDNVs). Subsequently, curcumin (CUR) was loaded onto GDNV by ultrasonic incubation. The optimum conditions for ginger-derived nanovesicles loaded with curcumin (CG) were ultrasound time of 3 min, a carrier-to-drug ratio (GDNV:CUR) of 1:1. The study achieved a high loading capacity (94.027% ± 0.094%) and encapsulation efficiency (89.300% ± 0.344%). Finally, the drugs' in vivo distribution and anti-colitis activity were investigated in mice. CG was primarily distributed in the colon after oral administration. Compared to CUR and GDNV, CG was superior in improving disease activity, colon length, liver and spleen coefficients, myeloperoxidase activity, and biochemical factor levels in ulcerative colitis (UC) mice. In addition, CG plays a protective role against UC by modulating serum metabolite levels and gut flora. In summary, our study demonstrated that GDNV can be used for CUR delivery with enhanced therapeutic potential.

Bioresponsive and transformable coacervate actuated by intestinal peristalsis for targeted treatment of intestinal bleeding and inflammation

Developing an oral in situ-forming hydrogel that targets the inflamed intestine to suppress bleeding ulcers and alleviate intestinal inflammation is crucial for effectively treating ulcerative colitis (UC). Here, inspired by sandcastle worm adhesives, we proposed a water-immiscible coacervate (EMNs-gel) with a programmed coacervate-to-hydrogel transition at inflammatory sites composed of dopa-rich silk fibroin matrix containing embedded inflammation-responsive core-shell nanoparticles. Driven by intestinal peristalsis, the EMNs-gel can be actuated forward and immediately transform into a hydrogel once contacting with the inflamed intestine to yield strong tissue adhesion, resulting from matrix metalloproteinases (MMPs)-triggered release of Fe3+ from embedded nanoparticles and rearrangement of polymer network of EMNs-gel on inflamed intestine surfaces. Extensive in vitro experiments and in vivo UC models confirmed the preferential hydrogelation behavior of EMNs-gel to inflamed intestine surfaces, achieving highly effective hemostasis, and displaying an extended residence time ( > 48 h). This innovative EMNs-gel provides a non-invasive solution that accurately suppresses severe bleeding and improves intestinal homeostasis in UC, showcasing great potential for clinical applications.

Layer by layer self-assembled hyaluronic acid nanoarmor for the treatment of ulcerative colitis

Natural compound-based treatments provide innovative ways for ulcerative colitis therapy. However, poor targeting and rapid degradation curtail its application, which needs to be addressed. Inspired by biomacromolecule-based materials, we have developed an orally administrated nanoparticle (GBP@HA NPs) using bovine serum albumin as a carrier for polyphenol delivery. The system synergizes galactosylated bovine serum albumin with two polyphenols, epigallocatechin gallate and tannic acid, which is then encased in "nanoarmor" of ε-Polylysine and hyaluronic acid to boost its stability and targeting. Remarkably, the nanoarmor demonstrated profound therapeutic effects in both acute and chronic mouse models of ulcerative colitis, mitigating disease symptoms via multiple mechanisms, regulating inflammation related factors and exerting a modulatory impact on gut microbiota. Further mechanistic investigations indicate that GBP@HA NPs may act through several pathways, including modulation of Keap1-Nrf2 and NF-κB signaling, as well as Caspase-1-dependent pyroptosis. Consequently, this novel armored nanotherapy promotes the way for enhanced polyphenol utilization in ulcerative colitis treatment research.

Curcumin-incorporated EGCG-based nano-antioxidants alleviate colon and kidney inflammation via antioxidant and anti-inflammatory therapy

Natural remedies are gaining attention as promising approaches to alleviating inflammation, yet their full potential is often limited by challenges such as poor bioavailability and suboptimal therapeutic effects. To overcome these limitations, we have developed a novel nano-antioxidant (EK) based on epigallocatechin gallate (EGCG) aimed at enhancing the oral and systemic bioavailability, as well as the anti-inflammatory efficacy, of curcumin (Cur) in conditions such as acute colon and kidney inflammation. EK is synthesized using a straightforward Mannich reaction between EGCG and L-lysine (K), resulting in the formation of EGCG oligomers. These oligomers spontaneously self-assemble into nanoparticles with a spherical morphology and an average diameter of approximately 160 nm. In vitro studies reveal that EK nanoparticles exhibit remarkable radical-scavenging capabilities and effectively regulate redox processes within macrophages, a key component in the body's inflammatory response. By efficiently encapsulating curcumin within these EK nanoparticles, we create Cur@EK, a formulation that demonstrates a synergistic anti-inflammatory effect. Specifically, Cur@EK significantly reduces the levels of pro-inflammatory cytokines TNF-α and IL-6 while increasing the anti-inflammatory cytokine IL-10 in lipopolysaccharide-stimulated macrophages, highlighting its potent anti-inflammatory properties. When administered either orally or intravenously, Cur@EK shows superior bioavailability compared to free curcumin and exhibits pronounced anti-inflammatory effects in mouse models of ulcerative colitis and acute kidney injury. These findings suggest that the EK nano-antioxidant platform not only enhances the bioavailability of curcumin but also amplifies its therapeutic impact, offering a promising new avenue for the treatment and management of inflammation in both oral and systemic contexts.

Construction of Yolk@shell Nanocomposite Particles with Controlled Multisized Pore Structures by Monomicelle Confined Assembly

Hollow nanoparticles with tunable structures and spatial and chemical specificity are considered as promising carriers. However, it remains a formidable challenge to endow hollow nanomaterials with precisely controlled multisized macro/mesoporous structures up to now. This paper demonstrates a "polydopamine (PDA) expansion-shrinkage" strategy combined with a monomicelle interfacial confined assembly method to achieve the highly controllable preparation of a series of yolk@shell PDA@SiO2 composite nanoparticles with structural asymmetry and a tunable multisized pore in the shell. The strategy allows systematic manipulation of the average pore size of large slit pores in the range of 15.4-86.5 nm by adjusting the reaction temperature. Benefiting from advantages such as an asymmetric structure and multilevel porosity, they exhibit excellent performance in the applications of on-demand loading of dual-sized cargoes, dual-propelled nanomotors, and particle size-selected encapsulation and separation. These findings provide inspiration for the construction of asymmetric yolk@shell structures with tunable multisized pores for a wide range of biological and chemical applications.

Nanotechnology for Targeted Inflammatory Bowel Disease Therapy: Challenges and Opportunities

Inflammatory bowel disease (IBD) is a complex and recurring inflammatory disorder that affects the gastrointestinal tract and is influenced by genetic predisposition, immune dysregulation, the gut microbiota, and environmental factors. Advanced therapies, such as biologics and small molecules, target diverse immune pathways to manage IBD. Nanoparticle (NP)-based drugs have emerged as effective tools, offering controlled drug release and targeted delivery. This review highlights NP modifications for anti-inflammatory purposes, utilizing changes such as those in size, charge, redox reactions, and ligand-receptor interactions in drug delivery systems. By using pathological and microenvironmental cues to guide NP design, precise targeting can be achieved. In IBD, a crucial aspect of NP intervention is targeting specific types of cells, such as immune and epithelial cells, to address compromised intestinal barrier function and reduce overactive immune responses. This review also addresses current challenges and future prospects, with the goal of advancing the development of NP-mediated strategies for IBD treatment.

Microcapsules based on biological macromolecules for intestinal health: A review

Intestinal dysfunction is becoming increasingly associated with neurological and endocrine issues, raising concerns about its impact on world health. With the introduction of several breakthrough technologies for detecting and treating intestinal illnesses, significant progress has been made in the previous few years. On the other hand, traditional intrusive diagnostic techniques are expensive and time-consuming. Furthermore, the efficacy of conventional drugs (not capsules) is reduced since they are more likely to degrade before reaching their target. In this context, microcapsules based on different types of biological macromolecules have been used to encapsulate active drugs and sensors to track intestinal ailments and address these issues. Several biomacromolecules/biomaterials (natural protein, alginate, chitosan, cellulose and RNA etc.) are widely used for make microcapsules for intestinal diseases, and can significantly improve the therapeutic effect and reduce adverse reactions. This article systematically summarizes microencapsulated based on biomacromolecules material for intestinal health control and efficacy enhancement. It also discusses the application and mechanism research of microencapsulated biomacromolecules drugs in reducing intestinal inflammation, in addition to covering the preparation techniques of microencapsulated drug delivery systems used for intestinal health. Microcapsule delivery systems' limits and potential applications for intestinal disease diagnosis, treatment, and surveillance were highlighted.

EGCG drives gut microbial remodeling-induced epithelial GPR43 activation to lessen Th1 polarization in colitis

Modulation of immune microenvironment is critical for inflammatory bowel disease (IBD) intervention. Epigallocatechin gallate (EGCG), as a natural low toxicity product, has shown promise in treating IBD. However, whether and how EGCG regulates the intestinal microenvironment is not fully understood. Here we report that EGCG lessens colitis by orchestrating Th1 polarization and self-amplification in a novel manner that required multilevel-regulated intestinal microecosystem. Mechanistically, EGCG activates GPR43 on IEC to inhibit Th1 polarization dependently of short chain fatty acid (SCFA)-producing gut microbiota. Inhibition of GPR43 activity weakens the protective effects of EGCG on colitis development. Moreover, we confirm that fecal SCFAs and/or intestinal GPR43 are limited in patients with colitis and are correlated with Th1 cell number. Taken together, our study reveals an intestinal microenvironment-dependent immunoregulatory effects of EGCG in treating IBD and provides insight into mechanisms of EGCG-based novel immunotherapeutic strategies for IBD.

Antimicrobial Peptides and Their Biomedical Applications: A Review

The emergence of drug resistance genes and the detrimental health effects caused by the overuse of antibiotics are increasingly prominent problems. There is an urgent need for effective strategies to antibiotics or antimicrobial resistance in the fields of biomedicine and therapeutics. The pathogen-killing ability of antimicrobial peptides (AMPs) is linked to their structure and physicochemical properties, including their conformation, electrical charges, hydrophilicity, and hydrophobicity. AMPs are a form of innate immune protection found in all life forms. A key aspect of the application of AMPs involves their potential to combat emerging antibiotic resistance; certain AMPs are effective against resistant microbial strains and can be modified through peptide engineering. This review summarizes the various strategies used to tackle antibiotic resistance, with a particular focus on the role of AMPs as effective antibiotic agents that enhance the host's immunological functions. Most of the recent studies on the properties and impregnation methods of AMPs, along with their biomedical applications, are discussed. This review provides researchers with insights into the latest advancements in AMP research, highlighting compelling evidence for the effectiveness of AMPs as antimicrobial agents.

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.

Bioinspired and bioderived nanomedicine for inflammatory bowel disease

Due to its chronic nature and complex pathophysiology, inflammatory bowel disease (IBD) poses significant challenges for treatment. The long-term therapies for patients, often diagnosed between the ages of 20 and 40, call for innovative strategies to target inflammation, minimize systemic drug exposure, and improve patients' therapeutic outcomes. Among the plethora of strategies currently pursued, bioinspired and bioderived nano-based formulations have garnered interest for their safety and versatility in the management of IBD. Bioinspired nanomedicine can host and deliver not only small drug molecules but also biotherapeutics, be made gastroresistant and mucoadhesive or mucopenetrating and, for these reasons, are largely investigated for oral administration, while surprisingly less for rectal delivery, recommended first-line treatment approach for several IBD patients. The use of bioderived nanocarriers, mostly extracellular vesicles (EVs), endowed with unique homing abilities, is still in its infancy with respect to the arsenal of nanomedicine under investigation for IBD treatment. An emerging source of EVs suited for oral administration is ingesta, that is, plants or milk, thanks to their remarkable ability to resist the harsh environment of the upper gastrointestinal tract. Inspired by the unparalleled properties of natural biomaterials, sophisticated avenues for enhancing therapeutic efficacy and advancing precision medicine approaches in IBD care are taking shape, although bottlenecks arising either from the complexity of the nanomedicine designed or from the lack of a clear regulatory pathway still hinder a smooth and efficient translation to the clinics. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Highly Effective Nobiletin-MPN in Yeast Microcapsules for Targeted Modulation of Oxidative Stress, NLRP3 Inflammasome Activation, and Immune Responses in Ulcerative Colitis

Inflammatory bowel disease (IBD) etiology is intricately linked to oxidative stress and inflammasome activation. Natural antioxidant nobiletin (NOB) contains excellent anti-inflammatory properties in alleviating intestinal injury. However, the insufficient water solubility and low bioavailability restrict its oral intervention for IBD. Herein, we constructed a highly efficient NOB-loaded yeast microcapsule (YM, NEFY) exhibiting marked therapeutic efficacy for dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) at a low oral dose of NOB (20 mg/kg). We utilized the metal polyphenol network (MPN) formed by self-assembly of epigallocatechin gallate (EGCG) and FeCl3 as the intermediate carrier to improve the encapsulation efficiency (EE) of NOB by 4.2 times. These microcapsules effectively alleviated the inflammatory reaction and oxidative stress of RAW264.7 macrophages induced by lipopolysaccharide (LPS). In vivo, NEFY with biocompatibility enabled the intestinal enrichment of NOB through controlled gastrointestinal release and macrophage targeting. In addition, NEFY could inhibit NLRP3 inflammasome and balance the macrophage polarization, which favors the complete intestinal mucosal barrier and recovery of colitis. Based on the oral targeted delivery platform of YM, this work proposes a novel strategy for developing and utilizing the natural flavone NOB to intervene in intestinal inflammation-related diseases.

Integrated oral microgel system ameliorates renal fibrosis by hitchhiking co-delivery and targeted gut flora modulation

BACKGROUND

Renal fibrosis is a progressive process associated with chronic kidney disease (CKD), contributing to impaired kidney function. Active constituents in traditional Chinese herbs, such as emodin (EMO) and asiatic acid (AA), exhibit potent anti-fibrotic properties. However, the oral administration of EMO and AA results in low bioavailability and limited kidney accumulation. Additionally, while oral probiotics have been accepted for CKD treatment through gut microbiota modulation, a significant challenge lies in ensuring their viability upon administration. Therefore, our study aims to address both renal fibrosis and gut microbiota imbalance through innovative co-delivery strategies.

RESULTS

In this study, we developed yeast cell wall particles (YCWPs) encapsulating EMO and AA self-assembled nanoparticles (NPYs) and embedded them, along with Lactobacillus casei Zhang, in chitosan/sodium alginate (CS/SA) microgels. The developed microgels showed significant controlled release properties for the loaded NPYs and prolonged the retention time of Lactobacillus casei Zhang (L. casei Zhang) in the intestine. Furthermore, in vivo biodistribution showed that the microgel-carried NPYs significantly accumulated in the obstructed kidneys of rats, thereby substantially increasing the accumulation of EMO and AA in the impaired kidneys. More importantly, through hitchhiking delivery based on yeast cell wall and positive modulation of gut microbiota, our microgels with this synergistic strategy of therapeutic and modulatory interactions could regulate the TGF-β/Smad signaling pathway and thus effectively ameliorate renal fibrosis in unilateral ureteral obstruction (UUO) rats.

CONCLUSION

In conclusion, our work provides a new strategy for the treatment of renal fibrosis based on hitchhiking co-delivery of nanodrugs and probiotics to achieve synergistic effects of disease treatment and targeted gut flora modulation.

Casein-quaternary chitosan complexes induced the soft assembly of egg white peptide and curcumin for ulcerative colitis alleviation

Soft assembly of peptide and curcumin (Cur) molecules enables functional integration by finding dynamic equilibrium states through non-covalent interactions. Herein, we developed two soft assembly systems, curcumin-egg white peptides (Cur-EWP) aggregations (AGs) and Cur-EWP-casein-quaternary chitosan (Cur-EWP-CA-QC) nanoparticles (NPs) to comparatively investigate their therapeutic effects on ulcerative colitis in mice and elucidate their underlying mechanism. Results revealed that Cur-EWP AGs, despite gastrointestinal tract instability, exhibited a propensity for swift accumulation within the colorectal region, enriching mucus-associated and short-chain fatty acid (SCAF)-producing bacteria, restoring the intestinal barrier damage. Whereas, Cur-EWP-CA-QC NPs, benefiting from their remarkable stability and exceptional mucosal adsorption properties, not only enhanced permeability of Cur and EWP in the small intestine to activate the immune response and boost tight junction protein expression but also, in their unabsorbed state, regulated the intestinal flora, exerting potent anti-inflammatory activity. Soft assembly of peptides and hydrophobic nutraceuticals could synergize biological activities to modulate chronic diseases.

Development strategies and application of antimicrobial peptides as future alternatives to in-feed antibiotics

The use of in-feed antibiotics has been widely restricted due to the significant environmental pollution and food safety concerns they have caused. Antimicrobial peptides (AMPs) have attracted widespread attention as potential future alternatives to in-feed antibiotics owing to their demonstrated antimicrobial activity and environment friendly characteristics. However, the challenges of weak bioactivity, immature stability, and low production yields of natural AMPs impede practical application in the feed industry. To address these problems, efforts have been made to develop strategies for approaching the AMPs with enhanced properties. Herein, we summarize approaches to improving the properties of AMPs as potential alternatives to in-feed antibiotics, mainly including optimization of structural parameters, sequence modification, selection of microbial hosts, fusion expression, and industrially fermentation control. Additionally, the potential for application of AMPs in animal husbandry is discussed. This comprehensive review lays a strong theoretical foundation for the development of in-feed AMPs to achieve the public health globally.

Epigallocatechin-3-gallate derived polymer coated Prussian blue for synergistic ROS elimination and antibacterial therapy

Reactive oxygen species (ROS) play a vital role in wound healing process by fighting against invaded bacteria. However, excess ROS at the wound sites lead to oxidative stress that can trigger deleterious effects, causing cell death, tissue damage and chronic inflammation. Therefore, we fabricated a core-shell structured nanomedicine with antibacterial and antioxidant properties via a facile and green strategy. Specifically, Prussian blue (PB) nanozyme was fabricated and followed by coating a layer of epigallocatechin-3-gallate (EGCG)-derived polymer via polyphenolic condensation reaction and self-assembly process, resulting in PB@EGCG. The introduction of PB core endowed EGCG-based polyphenol nanoparticles with excellent NIR-triggered photothermal properties. Besides, owing to multiple enzyme-mimic activity of PB and potent antioxidant capacity of EGCG-derived polymer, PB@EGCG exhibited a remarkable ROS-scavenging ability, mitigated intracellular ROS level and protected cells from oxidative damage. Under NIR irradiation (808 nm, 1.5 W/cm2), PB@EGCG (50 µg/mL) exerted synergistic EGCG-derived polymer-photothermal antibacterial activity against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). In vivo therapeutic effect was evaluated using a S. aureus-infected rat model indicated PB@EGCG with a prominent bactericidal ability could modulate the inflammatory microenvironment and accelerate wound healing. Overall, this dual-functional nanomedicine provides a promising strategy for efficient antibacterial therapy.

Lipoic acid-mediated oral drug delivery system utilizing changes on cell surface thiol expression for the treatment of diabetes and inflammatory diseases

Lipoic acid (LA), which has good safety and oral absorption, is obtained from various plant-based food sources and needs to be supplemented through human diet. Moreover, substances with a disulfide structure can enter cells through dynamic covalent disulfide exchange with thiol groups on the cell membrane surface. Based on these factors, we constructed LA-modified nanoparticles (LA NPs). Our results showed that LA NPs can be internalized into intestinal epithelial cells through surface thiols, followed by intracellular transcytosis via the endoplasmic reticulum-Golgi pathway. Further mechanistic studies indicated that disulfide bonds within the structure of LA play a critical role in this transport process. In a type I diabetes rat model, the oral administration of insulin-loaded LA NPs exhibited a more potent hypoglycemic effect, with a pharmacokinetic bioavailability of 5.42 ± 0.53%, representing a 1.6 fold enhancement compared to unmodified PEG NPs. Furthermore, a significant upregulation of surface thiols in inflammatory macrophages was reported. Thus, we turned our direction to investigate the uptake behavior of inflammatory macrophages with increased surface thiols towards LA NPs. Inflammatory macrophages showed a 2.6 fold increased uptake of LA NPs compared to non-inflammatory macrophages. Surprisingly, we also discovered that the antioxidant resveratrol facilitates the uptake of LA NPs in a concentration-dependent manner. This is mainly attributed to an increase in glutathione, which is involved in thiol uptake. Consequently, we employed LA NPs loaded with resveratrol for the treatment of colitis and observed a significant alleviation of colitis symptoms. These results suggest that leveraging the variations of thiol expression levels on cell surfaces under both healthy and diseased states through an oral drug delivery system mediated by the small-molecule nutrient LA can be employed for the treatment of diabetes and certain inflammatory diseases.

Bioinspired and biomimetic strategies for inflammatory bowel disease therapy

Inflammatory bowel disease (IBD) is an idiopathic chronic inflammatory bowel disease with high morbidity and an increased risk of cancer or death, resulting in a heavy societal medical burden. While current treatment modalities have been successful in achieving long-term remission and reducing the risk of complications, IBD remains incurable. Nanomedicine has the potential to address the high toxic side effects and low efficacy in IBD treatment. However, synthesized nanomedicines typically exhibit some degree of immune rejection, off-target effects, and a poor ability to cross biological barriers, limiting the development of clinical applications. The emergence of bionic materials and bionic technologies has reshaped the landscape in novel pharmaceutical fields. Biomimetic drug-delivery systems can effectively improve biocompatibility and reduce immunogenicity. Some bioinspired strategies can mimic specific components, targets or immune mechanisms in pathological processes to produce targeting effects for precise disease control. This article highlights recent research on bioinspired and biomimetic strategies for the treatment of IBD and discusses the challenges and future directions in the field to advance the treatment of IBD.

Metabolic Nanoregulator Remodels Gut Microenvironment for Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is strongly related to the occurrence of accumulation of toxic reactive oxygen species (ROS), inflammation of the mucosa, and an imbalance of intestinal microbes. However, current treatments largely focus on a single factor, yielding unsatisfactory clinical outcomes. Herein, we report a biocompatible and IBD-targeted metabolic nanoregulator (TMNR) that synergistically regulates cellular and bacterial metabolism. The TMNR comprises a melanin-gallium complex (MNR) encapsulated within a thermosensitive and colitis-targeting hydrogel, all composed of natural and FDA-approved components. The TMNR confers superior broad-spectrum antioxidant properties, effectively scavenging reactive oxygen species (ROS) and blocking inflammatory signaling pathways. The presence of Ga3+ in TMNR selectively disrupts iron metabolism in pathogenic microorganisms due to its structural resemblance to the iron atom. Additionally, incorporating a thermosensitive injectable hydrogel enables targeted delivery of TMNR to inflammatory regions, prolonging their retention time and providing a physical barrier function for optimizing IBD treatment efficacy. Collectively, TMNR effectively modulates the redox balance of inflamed colonic epithelial tissue and disrupts iron metabolism in pathogenic microorganisms, thereby eliminating inflammation and restoring intestinal homeostasis against IBD. Hence, this work presents a comprehensive approach for precise spatiotemporal regulation of the intestinal microenvironmental metabolism for IBD treatment.

Silk Fibroin Encapsulated Icariin Nanoparticles Mitigate Bisphenol A-Induced Spermatogenesis Dysfunction

Bisphenol A (BPA) is a prevalent endocrine disruptor found in natural environments. Exposure to BPA has been associated with male infertility. The natural phytochemical icariin (ICA) has demonstrated significant promise for the treatment of male infertility. However, its effectiveness is limited due to its low bioavailability, poor water solubility, and insufficient targeting abilities. Herein, novel nanoparticles are generated from the natural silk fibroin, which are used to load ICA. The efficient drug delivery system (ICA-SNPs) result in significantly focused drug distribution to spermatogonium, enhancing the anti-infertility properties of ICA, and can effectively mitigate spermatogenesis dysfunction induced by BPA, control serum sex hormone levels, and enhance testicular ultrastructure. Additionally, the ICA-SNPs restore spermatogenesis dysfunction primarily via the hormone biosynthesis, spermatogonium meiosis process, and glycerophospholipid metabolism.

Identification and immunoinfiltration analysis of key genes in ulcerative colitis using WGCNA

Objective

Ulcerative colitis (UC) is a chronic non-specific inflammatory bowel disease characterized by an unclear pathogenesis. This study aims to screen out key genes related to UC pathogenesis.

Methods

Bioinformatics analysis was conducted for screening key genes linked to UC pathogenesis, and the expression of the screened key genes was verified by establishing a UC mouse model.

Results

Through bioinformatics analysis, five key genes were obtained. Subsequent infiltration analysis revealed seven significantly different immune cell types between the UC and general samples. Additionally, animal experiment results illustrated markedly decreased body weight, visible colonic shortening and damage, along with a significant increase in the DAI score of the DSS-induced mice in the UC group in comparison with the NC group. In addition, H&E staining results demonstrated histological changes including marked inflammatory cell infiltration, loss of crypts, and epithelial destruction in the colon mucosa epithelium. qRT-PCR analysis indicated a down-regulation of ABCG2 and an up-regulation of IL1RN, REG4, SERPINB5 and TRIM29 in the UC mouse model. Notably, this observed trend showed a significant dependence on the concentration of DSS, with the mouse model of UC induced by 7% DSS demonstrating a more severe disease state compared to that induced by 5% DSS.

Conclusion

ABCG2, IL1RN, REG4, SERPINB5 and TRIM29 were screened out as key genes related to UC by bioinformatics analysis. The expression of ABCG2 was down-regulated, and that of IL1RN, REG4, SERPINB5 and TRIM29 were up-regulated in UC mice as revealed by animal experiments.

Nanocrystalline Cellulose Modulates Dysregulated Intestinal Barriers in Ulcerative Colitis

Ulcerative colitis (UC) is a recurrent chronic inflammation of the colon with increasing incidence and prevalence, which could increase the risk of colorectal cancer. It is urgent to find an effective method with few side effects. Nanocrystalline cellulose (NCC), which is from plant fibers, has a good biocompatibility and high biosafety. Herein, we used NCC to treat UC and evaluated its treatment effect by the disease activity index, intestinal pathology, inflammatory cytokines, tight junction proteins, and mucins. We studied the impact of NCC on mucin expression and gut microbiota to discuss the therapeutic mechanism. NCC can effectively treat UC by regulating the MAPK pathway of mucin 2 and the relative abundance of Akkermansia and Odoribacter, which could not cause the body damage. NCC could not cause body damage compared to the medications, while it had a better effect on the regulation of MUC2 compared to the present drug substitutes. NCC is a practical alternative for the treatment of UC.

Precursor template-induced egg white-derived peptides self-assembly for the enhancement of curcumin: Structure, environmental stability, and bioavailability

Natural multicomponent peptides with abundant bioactivity, varied sizes, and tunable interaction potential are available for rational designing novel self-assembled delivery carriers. Herein, we exploited zein-hyaluronic acid nanoparticles (Z-HA NPs) with a predetermined ordered structure as precursor templates to induce the self-assembly of egg white-derived peptides (EWDP) to generate stable spherical architectures for the enhancement of curcumin (Cur). The resulting Z-EWDP-HA NPs encapsulated hydrophobic Cur through robust hydrogen bonding and hydrophobic interactions with high encapsulation efficiency (97.38% at pH 7.0). The NPs presented superior Cur aqueous solubility, redispersibility, and photothermal stability. More importantly, the self-assembled EWDP could exert synergistic antioxidant activity with Cur and enhance the bioaccessibility of Cur. Meanwhile, the favorable biocompatibility and membrane affinity of EWDP further prolonged residence and time-controlled release feature of Cur in the small intestine. Precursor template-induced multicomponent peptides' self-assembly provides an efficient and controllable strategy for co-enhanced bioactivity and self-assembly capacity of peptides, which could dramatically broaden the functionalization of multicomponent peptides hydrolyzed from natural food proteins.

Plant Polyphenols Attenuate DSS-induced Ulcerative Colitis in Mice via Antioxidation, Anti-inflammation and Microbiota Regulation

The pathogenesis of ulcerative colitis (UC) is associated with inflammation, oxidative stress, and gut microbiota imbalance. Although most researchers have demonstrated the antioxidant bioactivity of the phenolic compounds in plants, their UC-curing ability and underlying mechanisms still need to be further and adequately explored. Herein, we studied the antioxidation-structure relationship of several common polyphenols in plants including gallic acid, proanthocyanidin, ellagic acid, and tannic acid. Furthermore, the in vivo effects of the plant polyphenols on C57BL/6 mice with dextran-sulfate-sodium-induced UC were evaluated and the action mechanisms were explored. Moreover, the interplay of several mechanisms was determined. The higher the number of phenolic hydroxyl groups, the stronger the antioxidant activity. All polyphenols markedly ameliorated the symptoms and pathological progression of UC in mice. Furthermore, inflammatory cytokine levels were decreased and the intestinal barrier was repaired. The process was regulated by the antioxidant-signaling pathway of nuclear-erythroid 2-related factor 2. Moreover, the diversity of the intestinal microbiota, Firmicutes-to-Bacteroides ratio, and relative abundance of beneficial bacteria were increased. An interplay was observed between microbiota regulation and oxidative stress, immunity, and inflammatory response. Furthermore, intestinal barrier repair was found to be correlated with inflammatory responses. Our study results can form a basis for comprehensively developing plant-polyphenol-related medicinal products.

High expression of antimicrobial peptides cathelicidin-BF in Pichia pastoris and verification of its activity

Antibacterial peptides are endogenous polypeptides produced by multicellular organisms to protect the host against pathogenic microbes, they show broad spectrum antimicrobial activities against various microorganisms and possess low propensity for developing resistance. The purpose of this study is to develop recombinant antibacterial peptide cathelicidin-BF by genetic engineering and protein engineering technology, and study its antibacterial activity in vitro and in vivo, so as to provide reference for the production and application of recombinant antibacterial peptide cathelicidin-BF. In this study, on account of Pichia pastoris eukaryotic expression system, we expressed and prepared antibacterial peptide cathelicidin-BF. Then, the minimum inhibitory concentration of antibacterial peptide cathelicidin-BF and the comparison with the antibacterial activity of antibiotics were determined through the antibacterial experiment in vitro. Chickens as infection model were used to verify the antibacterial peptide activity in vivo. The results show that the bacteriostatic ability of antibacterial peptide cathelicidin-BF is similar to that of antibiotics in certain concentration, and can reach the treatment level of antibiotics. Although the mode of administration of antibacterial peptide is still limited, this study can provide reference for the future research of antibacterial peptide.

Nogo-B inhibition restricts ulcerative colitis via inhibiting p68/miR-155 signaling pathway

BACKGROUND & AIMS

Ulcerative colitis (UC) is a main type of inflammatory bowel diseases which spreads globally during the westernization of lifestyle over the past few decades. However, the cause of UC is still not fully understood. We aimed to disclose the role of Nogo-B in the development of UC.

METHODS

Nogo-deficiency (Nogo^-/-) and wild-type male mice were treated with dextran sodium sulfate (DSS) to conduct a UC model, followed by determination of colon and serum inflammatory cytokines level. RAW264.7, THP1 and NCM460 cells were used to determine macrophage inflammation as well as proliferation and migration of NCM460 cells under Nogo-B or miR-155 intervention.

RESULTS

Nogo deficiency significantly reduced DSS-induced weight loss, colon length and weight reduction, and inflammatory cells accumulation in the intestinal villus, while increased the expression of tight junctions (TJs) proteins (Zonula occludens-1, Occludin) and adherent junctions (AJs) proteins (E-cadherin, α-catenin), implying that Nogo deficiency attenuated DSS-induced UC. Mechanistically, Nogo-B deficiency reduced TNFα, IL-1β and IL-6 levels in the colon, serum, RAW264.7 cells and THP1-derived macrophages. Furthermore, we identified that Nogo-B inhibition can reduce the maturation of miR-155, which is essential for Nogo-B-affected inflammatory cytokines expression. Interestingly, we determined that Nogo-B and p68 can interact with each other to promote the expression and activation of Nogo-B and p68, thus facilitating miR-155 maturation to induce macrophage inflammation. Blocking p68 inhibited Nogo-B, miR-155, TNFα, IL-1β and IL-6 expression. Moreover, the culture medium collected from Nogo-B overexpressed macrophages can inhibit enterocytes NCM460 cells proliferation and migration.

CONCLUSION

We disclose that Nogo deficiency reduced DSS-induced UC via inhibiting p68-miR-155-activated inflammation. Our results indicate that Nogo-B inhibition serves as a new potential therapeutic candidate for the prevention and treatment of UC.

A mesoporous polydopamine-derived nanomedicine for targeted and synergistic treatment of inflammatory bowel disease by pH-Responsive drug release and ROS scavenging

Repurposing clinically approved drugs to construct novel nanomedicines is currently a very attractive therapeutic approach. Selective enrichment of anti-inflammatory drugs and reactive oxygen species (ROS) scavenging at the region of inflammation by stimuli-responsive oral nanomedicine is an effective strategy for the treatment of inflammatory bowel disease (IBD). This study reports a novel nanomedicine, which is based on the excellent drug loading and free radical scavenging ability of mesoporous polydopamine nanoparticles (MPDA NPs). By initiating polyacrylic acid（PAA）polymerization on its surface, a "core-shell" structure nano-carrier with pH response is constructed. Then, under alkaline conditions, using the π-π stacking and hydrophobic interaction between the anti-inflammatory drug sulfasalazine (SAP) and MPDA, the nanomedicines (PAA@MPDA-SAP NPs) loaded efficiently (928 μ g mg^-1) of SAP was successfully formed. Our results reveal that PAA@MPDA-SAP NPs can pass through the upper digestive tract smoothly and finally accumulate in the inflamed colon. Through the synergistic effect of anti-inflammation and antioxidation, it can effectively reduce the expression of pro-inflammatory factors and enhance the intestinal mucosal barrier, and finally significantly alleviate the symptoms of colitis in mice. Furthermore, we confirmed that PAA@MPDA-SAP NPs have good biocompatibility and anti-inflammatory repair ability under inflammation induction through human colonic organoids. In summary, this work provides a theoretical basis for the development of nanomedicines for IBD therapy.

Biodegradable Polymeric Nanoparticles Loaded with Flavonoids: A Promising Therapy for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a group of disorders that cause chronic non-specific inflammation in the gastrointestinal (GI) tract, primarily affecting the ileum and colon. The incidence of IBD has risen sharply in recent years. Despite continuous research efforts over the past decades, the aetiology of IBD is still not fully understood and only a limited number of drugs are available for its treatment. Flavonoids, a ubiquitous class of natural chemicals found in plants, have been widely used in the prevention and treatment of IBD. However, their therapeutic efficacy is unsatisfactory due to poor solubility, instability, rapid metabolism, and rapid systemic elimination. With the development of nanomedicine, nanocarriers can efficiently encapsulate various flavonoids and subsequently form nanoparticles (NPs), which greatly improves the stability and bioavailability of flavonoids. Recently, progress has also been made in the methodology of biodegradable polymers that can be used to fabricate NPs. As a result, NPs can significantly enhance the preventive or therapeutic effects of flavonoids on IBD. In this review, we aim to evaluate the therapeutic effect of flavonoid NPs on IBD. Furthermore, we discuss possible challenges and future perspectives.

Alterations in metabolome and microbiome signatures provide clues to the role of antimicrobial peptide KT2 in ulcerative colitis

Introduction

Ulcerative colitis (UC) is an inflammatory disease of the intestinal tract with unknown etiology. Both genetic and environmental factors are involved in the occurrence and development of UC. Understanding changes in the microbiome and metabolome of the intestinal tract is crucial for the clinical management and treatment of UC.

Methods

Here, we performed metabolomic and metagenomic profiling of fecal samples from healthy control mice (HC group), DSS (Dextran Sulfate Sodium Salt) -induced UC mice (DSS group), and KT2-treated UC mice (KT2 group).

Results and Discussion

In total, 51 metabolites were identified after UC induction, enriched in phenylalanine metabolism, while 27 metabolites were identified after KT2 treatment, enriched in histidine metabolism and bile acid biosynthesis. Fecal microbiome analysis revealed significant differences in nine bacterial species associated with the course of UC, including Bacteroides, Odoribacter, and Burkholderiales, which were correlated with aggravated UC, and Anaerotruncus, Lachnospiraceae, which were correlated with alleviated UC. We also identified a disease-associated network connecting the above bacterial species with UC-associated metabolites, including palmitoyl sphingomyelin, deoxycholic acid, biliverdin, and palmitoleic acid. In conclusion, our results indicated that Anaerotruncus, Lachnospiraceae, and Mucispirillum were protective species against DSS-induced UC in mice. The fecal microbiomes and metabolomes differed significantly among the UC mice and KT2-treated and healthy-control mice, providing potential evidence for the discovery of biomarkers of UC.

Harnessing polymer-derived drug delivery systems for combating inflammatory bowel disease

The inflammatory bowel disease (IBD) is incurable, chronic, recrudescent disorders in the inflamed intestines. Current clinic treatments are challenged by systemic exposure-induced severe side effects, inefficiency after long-term treatment, and increased risks of infection and malignancy due to immunosuppression. Fortunately, naturally bioactive small molecules, reactive oxygen species scavengers (or antioxidants), and gut microbiota modulators have emerged as promising candidates for the IBD treatment. Polymeric systems have been engineered as a delivery vehicle to improve the bioavailability and efficacy of these therapeutic agents through targeting the mucosa and enhancing intestinal adhesion and retention, and reduce their systemic toxicity. Herein we survey polymer-derived drug delivery systems for combating the IBD. Advanced delivery technologies, therapeutic intervention strategies, and the principles for the construction of hierarchical, mucosa-targeting, and bioresponsive systems are elaborated, providing insights into design and development of from-bench-to-bedside drug delivery polymeric systems for the IBD treatment.

Multifunctional hydrogels based on chitosan, hyaluronic acid and other biological macromolecules for the treatment of inflammatory bowel disease: A review

Hydrogel is a three-dimensional network polymer material rich in water. It is widely used in the biomedical field because of its unique physical and chemical properties and good biocompatibility. In recent years, the incidence of inflammatory bowel disease (IBD) has gradually increased, and the disadvantages caused by traditional drug treatment of IBD have emerged. Therefore, there is an urgent need for new treatments to alleviate IBD. Hydrogel has become a potential therapeutic platform. However, there is a lack of comprehensive review of functional hydrogels for IBD treatment. This paper first summarizes the pathological changes in IBD sites. Then, the action mechanisms of hydrogels prepared from chitosan, sodium alginate, hyaluronic acid, functionalized polyethylene glycol, cellulose, pectin, and γ-polyglutamic acid on IBD were described from aspects of drug delivery, peptide and protein delivery, biologic therapies, loading probiotics, etc. In addition, the advanced functions of IBD treatment hydrogels were summarized, with emphasis on adhesion, synergistic therapy, pH sensitivity, particle size, and temperature sensitivity. Finally, the future development direction of IBD treatment hydrogels has been prospected.