Mo3Se4 nanoparticle with ROS scavenging and multi-enzyme activity for the treatment of DSS-induced colitis in mice

Microenvironment-sensitive nanozymes for tissue regeneration

Tissue defect is one of the significant challenges encountered in clinical practice. Nanomaterials, including nanoparticles, nanofibers, and metal-organic frameworks, have demonstrated an extensive potential in tissue regeneration, offering a promising avenue for future clinical applications. Nonetheless, the intricate landscape of the inflammatory tissue microenvironment has engendered challenges to the efficacy of nanomaterial-based therapies. This quandary has spurred researchers to pivot towards advanced nanotechnological remedies for overcoming these therapeutic constraints. Among these solutions, microenvironment-sensitive nanozymes have emerged as a compelling instrument with the capacity to reshape the tissue microenvironment and enhance the intricate process of tissue regeneration. In this review, we summarize the microenvironmental characteristics of damaged tissues, offer insights into the rationale guiding the design and engineering of microenvironment-sensitive nanozymes, and explore the underlying mechanisms that underpin these nanozymes' responsiveness. This analysis includes their roles in orchestrating cellular signaling, modulating immune responses, and promoting the delicate process of tissue remodeling. Furthermore, we discuss the diverse applications of microenvironment-sensitive nanozymes in tissue regeneration, including bone, soft tissue, and cartilage regeneration. Finally, we shed our sights on envisioning the forthcoming milestones in this field, prospecting a future where microenvironment-sensitive nanozymes contribute significantly to the development of tissue regeneration and improved clinical outcomes.

The prophylaxis functions of Lactobacillus fermentum GLF-217 and Lactobacillus plantarum FLP-215 on ulcerative colitis via modulating gut microbiota of mice

BACKGROUND

The strong connection between gut microbes and human health has been confirmed by an increasing number of studies. Although probiotics have been found to relieve ulcerative colitis, the mechanism varies by the species involved. In this study, the physiological, immune and pathological factors of mice were measured and shotgun metagenomic sequencing was conducted to investigate the potential mechanisms in preventing ulcerative colitis.

RESULTS

The results demonstrated that ingestion of Lactobacillus fermentum GLF-217 and Lactobacillus plantarum FLP-215 significantly alleviated ulcerative colitis induced by dextran sulfate sodium (DSS), as evidenced by the increase in body weight, food intake, water intake and colon length as well as the decrease in disease activity index, histopathological score and inflammatory factor. Both strains not only improved intestinal mucosa by increasing mucin-2 and zonula occludens-1, but also improved the immune system response by elevating interleukin-10 levels and decreasing the levels of interleukin-1β, interleukin-6, tumor necrosis factor-α and interferon-γ. Moreover, L. fermentum GLF-217 and L. plantarum FLP-215 play a role in preventing DSS-induced colitis by regulating the structure of gut microbiota and promoting the formation of short-chain fatty acids.

CONCLUSIONS

This study may provide a reference for the prevention strategy of ulcerative colitis. © 2024 Society of Chemical Industry.

W-GA nanodots restore intestinal barrier functions by regulating flora disturbance and relieving excessive oxidative stress to alleviate colitis

Inflammatory bowel disease (IBD) may arise due to disruption of mucosal barriers as a result of dysregulation of the intestinal flora and excessive oxidative stress. The creation of nanomaterials with only microbiota-regulating effects often leads to inadequate therapeutic outcomes caused by the disruption of a healthy microbial balance and the emergence of tissue harm caused by excessive oxidative stress. This report describes the multifunctional activity of ultrasmall W-GA nanodots, which can precisely regulate the intestinal microbiome by inhibiting the abnormal expansion of Enterobacteriaceae during colitis and alleviating the damage caused by oxidative stress to the reconstructive microflora, ultimately restoring intestinal barrier function. W-GA nanodots have been synthesized through a simple coordination reaction and can be dispersed in various solvents in vitro, demonstrating favorable safety profiles in cells, significant clearance of reactive oxygen and nitrogen species (RONS), and increased cell survival in models of oxidative stress induced by hydrogen peroxide (H2O2). Through oral or intravenous administration, the W-GA nanodots were shown to be highly safe when tested in vivo, and they effectively reduced colon damage in mice with DSS-induced colitis by restoring the integrity of the intestinal barrier. W-GA nanodots have enabled the integration of microflora reprogramming and RONS clearance, creating a potent therapeutic strategy for treating gut inflammation. Consequently, the development of W-GA nanodots represents a promising strategy for enhancing the formation and preservation of the intestinal barrier to treat IBD by suppressing the growth of Enterobacteriaceae, a type of facultative anaerobic bacterium, and facilitating the effective removal of RONS. Ultimately, this leads to the restoration of the intestinal barrier's functionality. STATEMENT OF SIGNIFICANCE: An increasing number of nanoparticles are under development for treating inflammatory bowel disease. Although they can alleviate inflammation symptoms by regulating reactive oxygen and nitrogen species (RONS) and microbiota, their understanding of the mechanism behind microbiota regulation is limited. This study synthesized W-GA nanodots using a straightforward one-pot synthesis method. Simple synthesis holds significant promise for clinical applications, as it encompasses multiple nanoenzyme functions and also exhibits Enterobacteriaceae inhibitory properties.Thus, it contributes to ameliorating the current medical landscape of inflammatory bowel disease.

Gigantol ameliorates DSS-induced colitis via suppressing β2 integrin mediated adhesion and chemotaxis of macrophage

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium, recognized as "Shihu" in traditional Chinese medicine, holds a rich history of medicinal utilization documented in the Chinese Pharmacopoeia. Ancient texts like "Shen Nong Ben Cao Jing" extol Dendrobium's virtues as a superior herbal medicine fortifying "Yin" and invigorating the five viscera. Dendrobium is extensively employed for the treatment of gastrointestinal inflammatory disorders, showcasing significant therapeutic efficacy, particularly against ulcerative colitis (UC), within the realm of Chinese ethnopharmacology. Dendrobium plays crucial pharmacological roles due to its rich content of polysaccharides, alkaloids, phenanthrenes, and bibenzyls. Gigantol, a prominent bibenzyl compound, stands out as one of the most vital active constituents within Dendrobium, the gigantol content of Dendrobium leaves can reach approximately 4.79 μg/g. Its significance lies in being recognized as a noteworthy anti-inflammatory compound derived from Dendrobium.

AIM OF THE STUDY

Given the pivotal role of gigantol as a primary active substance in Dendrobium, the therapeutic potential of gigantol for gastrointestinal diseases remains enigmatic. Our present investigation aimed to evaluate the therapeutic effects of gigantol on dextran sulfate sodium (DSS)-induced colitis and reveal its potential mechanism in countering UC activity.

MATERIALS AND METHODS

The protective efficacy of gigantol against colitis was assessed by examining the histopathological changes and conducting biochemical analyses of colon from DSS-challenged mice. Assessments focused on gigantol's impact on improving the intestinal epithelial barrier and its anti-inflammatory effects in colonic tissues of colitis mice. Investigative techniques included the exploration of the macrophage inflammatory signaling pathway via qPCR and Western blot analyses. In vitro studies scrutinized macrophage adhesion, migration, and chemotaxis utilizing transwell and Zigmond chambers. Furthermore, F-actin and Rac1 activation assays detailed cellular cytoskeletal remodeling. The potential therapeutic target of gigantol was identified and validated through protein binding analysis, competitive enzyme-linked immunosorbent assay (ELISA), cellular thermal shift assay (CETSA), and drug affinity responsive target stability (DARTS) assay. The binding sites between gigantol and its target were predicted via molecular docking.

RESULTS

Gigantol ameliorated symptoms of DSS-induced colitis, rectified damage to the intestinal barrier, and suppressed the production of pro-inflammatory cytokines in colonic tissues. Intriguingly, gigantol significantly curtailed NF-κB signaling activation in the colons of DSS-induced colitis mice. Notably, gigantol impaired the β2 integrin-dependent adhesion and migratory capacity of RAW264.7 cells. Moreover, gigantol notably influenced the cytoskeleton remodeling of RAW264.7 cells by suppressing Vav1 phosphorylation and Rac1 activation. Mechanistically, gigantol interacted with β2 integrin, subsequently diminishing binding affinity with intercellular adhesion molecule-1 (ICAM-1).

CONCLUSIONS

In conclusion, these findings elucidate that gigantol ameliorates DSS-induced colitis by antagonizing β2 integrin-mediated macrophage adhesion, migration, and chemotaxis, thus it may impede macrophage recruitment and infiltration into colonic tissues. This study suggests that gigantol shows promise as a viable candidate for clinical colitis therapy.

Melanin Nanoparticle-Modified Probiotics for Targeted Synergistic Therapy of Ulcerative Colitis

Ulcerative colitis (UC) is a recurrent chronic mucosal inflammation disease whose most significant pathological characteristics are intestinal inflammation and damaged mucosal barrier induced by reactive oxygen/nitrogen species, abnormal immune microenvironment, and intestinal microecological imbalance. Oral probiotics are a living therapy for intestinal diseases, but their clinical application is hindered by poor bacterial biological activity and insufficient intestinal retention. Here, we developed a targeted oral formulation, functionalized probiotic Lf@MPB, with Lactobacillus fermentum (Lf) as the core and modified melanin nanoparticles (MNPs) on its surface through a click reaction of tricarboxyphenylboronic acid for synergistic therapy of UC. In vitro experiments showed that Lf@MPB not only possessed strong free radical scavenging ability, reduced cellular mitochondrial polarization, and inhibited apoptosis but also significantly enhanced the viability of Lf probiotics in simulated gastrointestinal fluid. Fluorescence imaging in vivo revealed the high accumulation of Lf@MPB at the site of intestinal inflammation in dextran sulfate sodium-induced UC mice. Moreover, in vivo results demonstrated that Lf@MPB effectively alleviated oxidative stress and inflammatory response and restored the intestinal barrier. In addition, 16S rRNA gene sequencing verified that Lf@MPB could increase the abundance and diversity of intestinal microbial communities and optimize microbial composition to inhibit the progression of UC. This work combines effective antioxidant and anti-inflammatory strategies with the oral administration of functionalized probiotics to provide a promising alternative for UC treatment.

T Cell-Derived Apoptotic Extracellular Vesicles Hydrolyze cGAMP to Alleviate Radiation Enteritis via Surface Enzyme ENPP1

Radiation enteritis is the most common complication of pelvic radiotherapy, but there is no effective prevention or treatment drug. Apoptotic T cells and their products play an important role in regulating inflammation and maintaining physiological immune homeostasis. Here it is shown that systemically infused T cell-derived apoptotic extracellular vesicles (ApoEVs) can target mice irradiated intestines and alleviate radiation enteritis. Mechanistically, radiation elevates the synthesis of intestinal 2'3' cyclic GMP-AMP (cGAMP) and activates cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) proinflammatory pathway. After systemic infusion of ApoEVs, the ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1) enriches on the surface of ApoEVs hydrolyze extracellular cGAMP, resulting in inhibition of the cGAS-STING pathway activated by irradiation. Furthermore, after ApoEVs are phagocytosed by phagocytes, ENPP1 on ApoEVs hydrolyzed intracellular cGAMP, which serves as an intracellular cGAMP hydrolyzation mode, thereby alleviating radiation enteritis. The findings shed light on the intracellular and extracellular hydrolysis capacity of ApoEVs and their role in inflammation regulation.

Ferulic Acid Inhibits Arsenic-Induced Colon Injury by Improving Intestinal Barrier Function

The prolonged exposure to arsenic results in intestinal barrier dysfunction, which is strongly concerned with detrimental processes such as oxidative stress and the inflammatory response. Ferulic acid (FA), as a phenolic acid, possesses the capability to mitigate arsenic-induced liver damage and cardiotoxic effects dependent on inhibition of oxidative stress and inflammatory responses. FA can mitigate testicular tissue damage and alveolar epithelial dysfunction, the mechanism of which may rely on nuclear factor erythroid 2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) activation and nuclear factor-kappa B (NF-κB) pathway blocking. Based on the antioxidant and anti-inflammatory properties of FA, we speculated that FA might have the potential to inhibit arsenic-induced intestinal damage. To confirm this scientific hypothesis, mice exposed to sodium arsenite were treated with FA to observe colonic histopathology and TJ protein levels, and oxidative stress and TJ protein levels in Caco-2 cells exposed to sodium arsenite were assessed after FA intervention. In addition, molecular levels of NF-κB and Nrf2/HO-1 pathway in colon and Caco-2 cells were also detected. As shown in our data, FA inhibited arsenic-induced colon injury, which was reflected in the improvement of mucosal integrity, the decrease of down-regulated expression of tight junction (TJ) proteins (Claudin-1, Occludin, and ZO-1) and the inhibition of oxidative stress. Similarly, treatment with FA attenuated the inhibitory effect of arsenic on TJ protein expression in Caco-2 cells. In addition to suppressing the activation of NF-κB pathway, FA retrieved the activation of Nrf2/HO-1 pathway in colon and intestinal epithelial cells induced by arsenic. In summary, our findings propose that FA has the potential to mitigate arsenic-induced intestinal damage by preserving the integrity of intestinal epithelial TJs and suppressing oxidative stress. These results lay the groundwork for the potential use of FA in treating colon injuries caused by arsenic.

Insights into the Role of Glutathione Peroxidase 3 in Non-Neoplastic Diseases

Reactive oxygen species (ROSs) are byproducts of normal cellular metabolism and play pivotal roles in various physiological processes. Disruptions in the balance between ROS levels and the body's antioxidant defenses can lead to the development of numerous diseases. Glutathione peroxidase 3 (GPX3), a key component of the body's antioxidant system, is an oxidoreductase enzyme. GPX3 mitigates oxidative damage by catalyzing the conversion of hydrogen peroxide into water. Beyond its antioxidant function, GPX3 is vital in regulating metabolism, modulating cell growth, inducing apoptosis and facilitating signal transduction. It also serves as a significant tumor suppressor in various cancers. Recent studies have revealed aberrant expression of GPX3 in several non-neoplastic diseases, associating it with multiple pathological processes. This review synthesizes the current understanding of GPX3 expression and regulation, highlighting its extensive roles in noncancerous diseases. Additionally, this paper evaluates the potential of GPX3 as a diagnostic biomarker and explores emerging therapeutic strategies targeting this enzyme, offering potential avenues for future clinical treatment of non-neoplastic conditions.

Colon-targeted oral nanoliposomes loaded with psoralen alleviate DSS-induced ulcerative colitis

Oral administration, while convenient, but complex often faces challenges due to the complexity of the digestive environment. In this study, we developed a nanoliposome (NLP) encapsulating psoralen (P) and coated it with chitosan (CH) and pectin (PT) to formulate PT/CH-P-NLPs. PT/CH-P-NLPs exhibit good biocompatibility, superior to liposomes loaded with psoralen and free psoralen alone. After oral administration, PT/CH-P-NLPs remain stable in the stomach and small intestine, followed by a burst release of psoralen after reaching the slightly alkaline and gut microbiota-rich colon segment. In the DSS-induced ulcerative colitis of mice, PT/CH-P-NLPs showed significant effects on reducing inflammation, mitigating oxidative stress, protecting the integrity of the colon mucosal barrier, and modulating the gut microbiota. In conclusion, the designed nanoliposomes demonstrated the effective application of psoralen in treating ulcerative colitis.

Biomimetic Integrated Nanozyme for Flare and Recurrence of Gouty Arthritis

Flare and multiple recurrences pose significant challenges in gouty arthritis. Traditional treatments provide temporary relief from inflammation but fail to promptly alleviate patient pain or effectively prevent subsequent recurrences. It should also be noted that both anti-inflammation and metabolism of uric acid are necessary for gouty arthritis, calling for therapeutic systems to achieve these two goals simultaneously. In this study, we propose a biomimetic integrated nanozyme, HMPB-Pt@MM, comprising platinum nanozyme and hollow Prussian blue. It demonstrates anti-inflammatory properties by eliminating reactive oxygen species and reducing infiltration of inflammatory macrophages. Additionally, it rapidly targets inflamed ankles through the camouflage of macrophage membranes. Furthermore, HMPB-Pt@MM exhibits urate oxidase-like capabilities, continuously metabolizing locally elevated uric acid concentrations, ultimately inhibiting multiple recurrences of gouty arthritis. In summary, HMPB-Pt@MM integrates ROS clearance with uric acid metabolism, offering a promising platform for the treatment of gouty arthritis.

Ceria Nanoparticle Systems Alleviate Degenerative Changes in Mouse Postovulatory Aging Oocytes by Reducing Oxidative Stress and Improving Mitochondrial Functions

Postovulatory aging oocytes usually feature diminished potential for fertilization and poor embryonic development due to enhanced oxidative damage to the subcellular organelles and macromolecules, which stands as a formidable obstacle in assisted reproductive technologies (ART). Here, we developed lipoic acid (LA) and polyethylene glycol (PEG)-modified CeO2 nanoparticles (LA-PEG-CeNPs) with biocompatibility, enzyme-like autocatalytic activity, and free radical scavenging capacity. We further investigated the LA-PEG-CeNPs effect in mouse postovulatory oocytes during in vitro aging. The results showed that LA-PEG-CeNPs dramatically reduced the accumulation of ROS in aging oocytes, improving mitochondrial dysfunction; they also down-regulated the pro-apoptotic activity by rectifying cellular caspase-3, cleaved caspase-3, and Bcl-2 levels. Consistently, this nanoenzyme prominently alleviated the proportion of abnormalities in spindle structure, chromosome alignment, microtubule stability, and filamentous actin (F-actin) distribution in aging oocytes, furthermore decreased oocyte fragmentation, and improved its ability of fertilization and development to blastocyst. Taken together, our finding suggests that LA-PEG-CeNPs can alleviate oxidative stress damage on oocyte quality during postovulatory aging, implying their potential value for clinical practice in assisted reproduction.

Wheat peptide alleviates DSS-induced colitis by activating the Keap1-Nrf2 signaling pathway and maintaining the integrity of the gut barrier

Inflammatory bowel disease (IBD) is difficult to cure, and formulating a dietary plan is an effective means to prevent and treat this disease. Wheat peptide contains a variety of bioactive peptides with anti-inflammatory and antioxidant functions. The results of this study showed that preventive supplementation with wheat peptide (WP) can significantly alleviate the symptoms of dextran sulfate sodium (DSS)-induced colitis in mice. WP can increase body weight, alleviate colon shortening, and reduce disease activity index (DAI) scores. In addition, WP improved intestinal microbial disorders in mice with colitis. Based on LC-MS, a total of 313 peptides were identified in WP, 4 of which were predicted to be bioactive peptides. The regulatory effects of WP and four bioactive peptides on the Keap1-Nrf2 signaling pathway were verified in Caco-2 cells. In conclusion, this study demonstrated that WP alleviates DSS-induced colitis by helping maintain gut barrier integrity and targeting the Keap1-Nrf2 axis; these results provided a rationale for adding WP to dietary strategies to prevent IBD.

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.

Protective effect of carbon dots as antioxidants on intestinal inflammation by regulating oxidative stress and gut microbiota in nematodes and mouse models

Inflammatory bowel disease (IBD) is a recurrent chronic colitis disease with increasing incidence and prevalence year by year. The single efficacy and significant side effects of traditional IBD treatment drugs have promoted the flourishing development of new drugs. Inspired by many health benefits of carbon dots (CDs) based nanomedicine in biomedical applications, a metal-free carbon dots (CP-CDs) was synthesized from citric acid and polyethylene polyamine to treat colitis. Oxidative stress tests at the cellular and nematode levels demonstrated CP-CDs have good antioxidant effects, while the toxicity of CP-CDs to cells and nematodes is low. CP-CDs were further applied to dextran sodium sulfate (DSS)-induced colitis in mice models, and it was found that CP-CDs can reduce the disease activity index (DAI) score of colon tissue and restore the intestinal barrier. Further, the anti-colitis mechanisms of CP-CDs were explored, one of which is to regulate intestinal oxidative stress in inflammatory mice, further reducing the expression of inflammatory cytokines, and thus alleviating colitis. Notably, 16S rRNA sequence analysis showed that the abundance of beneficial bacteria (Ligilactobacillus and Enterorhabdus) in the intestinal tract increased, while that of harmful bacteria (unclassified_Clostridia_UCG_014) decreased after CP-CDs treatment, indicating that CP-CDs rebalancing the gut microbiota destroyed by DSS is another important mechanism. In short, these non-toxic carbon dots not only have the potential for multi-factor combined relief of colitis but also offer an alternative therapy medicine for patients suffering from IBD.

Tunable Structured 2D Nanobiocatalysts: Synthesis, Catalytic Properties and New Horizons in Biomedical Applications

2D materials have offered essential contributions to boosting biocatalytic efficiency in diverse biomedical applications due to the intrinsic enzyme-mimetic activity and massive specific surface area for loading metal catalytic centers. Since the difficulty of high-quality synthesis, the varied structure, and the tough choice of efficient surface loading sites with catalytic properties, the artificial building of 2D nanobiocatalysts still faces great challenges. Here, in this review, a timely and comprehensive summarization of the latest progress and future trends in the design and biotherapeutic applications of 2D nanobiocatalysts is provided, which is essential for their development. First, an overview of the synthesis-structure-fundamentals and structure-property relationships of 2D nanobiocatalysts, both metal-free and metal-based is provided. After that, the effective design of the active sites of nanobiocatalysts is discussed. Then, the progress of their applied research in recent years, including biomedical analysis, biomedical therapeutics, pharmacokinetics, and toxicology is systematically highlighted. Finally, future research directions of 2D nanobiocatalysts are prospected. Overall, this review to provide cutting-edge and multidisciplinary guidance for accelerating future developments and biomedical applications of 2D nanobiocatalysts is expected.

Hypersampsonone H attenuates ulcerative colitis via inhibition of PDE4 and regulation of cAMP/PKA/CREB signaling pathway

BACKGROUND AND OBJECTIVES

Ulcerative colitis (UC) is a recurrent intestinal inflammatory disease which poses a serious threat to the life of patients. However, there are no specific drugs for UC yet. Hypericum sampsonii Hance (HS) is a Chinese herbal medicine traditionally used to treat enteritis and dysentery. Our previous studies have demonstrated that HS holds potential anti-UC effects, and a novel compound named Hypersampsonone H (HS-1) isolated from HS possesses significant anti-inflammatory activity. However, the beneficial effects of HS-1 on UC remain unclear. This study aimed to investigate the therapeutic effects of HS-1 on UC and its potential mechanisms, both in vitro and in vivo.

METHODS

The in vitro model was employed using LPS-induced RAW264.7 cells to investigate the anti-inflammatory effects of HS-1 and its possible mechanisms. Furthermore, the therapeutic efficacy and potential mechanisms of HS-1 against dextran sulfate sodium (DSS)-induced acute colitis were assessed through histopathological examination, biochemical analysis, and molecular docking.

RESULTS

In vitro, HS-1 significantly reduced LPS-induced inflammatory responses, as indicated by inhibiting NO production, down-regulating the overexpression of COX-2 and iNOS, as well as regulating the imbalanced levels of IL-6, TNF-α, and IL-10. Moreover, HS-1 also inhibited the expression of PDE4, elevated the intracellular cAMP level, and promoted the phosphorylation of CREB, thereby activating the PKA/CREB pathway in RAW264.7 cells. In vivo, HS-1 demonstrated therapeutic capacity against DSS-induced colitis by alleviating the symptoms of colitis mice, regulating the abnormal expression of inflammatory mediators, protecting the integrity of intestinal epithelial barrier, and reducing tissue fibrosis. Consistently, HS-1 was found to decrease the expression of PDE4 isoforms, subsequently activating the cAMP/PKA/CREB signaling pathway. Furthermore, the molecular docking results indicated that HS-1 exhibited a high affinity for PDE4, particularly PDE4D. Further mechanistic validation in vitro demonstrated that HS-1 possessed a synergistic effect on forskolin and an antagonistic effect on H-89 dihydrochloride, thereby exerting anti-inflammatory effects through the cAMP/PKA/CREB signaling pathway.

CONCLUSION

We disclose that HS-1 serves as a promising candidate drug for the treatment of UC by virtue of its ability to reduce DSS-induced colitis via the inhibition of PDE4 and the activation of cAMP/PKA/CREB signaling pathway.

Colon-targeted piperine-glycyrrhizic acid nanocrystals for ulcerative colitis synergetic therapy via macrophage polarization

Ulcerative colitis (UC) is a chronic inflammatory disease that affects the gastrointestinal tract and is characterized by immune dysregulation. Oral administration of nanoformulations containing immunomodulators is a desirable approach to treating UC. However, low drug-loading (<10%, typically), premature drug release, and systemic absorption of these nanoformulations continue to be significant challenges restricting clinical applications. Herein, we developed colon-targeted piperine-glycyrrhizic acid nanocrystals (ES100-PIP/GA NCs) to treat UC through the regulation of macrophages. The ES100-PIP/GA NCs exhibited ultra-high drug loading and colon-specific drug release. In vitro studies demonstrated that the ES100-PIP/GA NCs could effectively be internalized by lipopolysaccharide (LPS)-induced RAW 264.7 and Caco-2 cells. More importantly, the ES100-PIP/GA NCs could downregulate pro-inflammatory factors (IL-1β, IL-17A), upregulate anti-inflammatory factors (TGF-β1), and repair the intestinal mucosal barrier. In a murine model of acute colitis induced by dextran sodium sulfate (DSS), ES100-PIP/GA NCs could protect PIP and GA from gastric acid destruction, reach the colon, and significantly inhibit colitis. Surprisingly, ES100-PIP/GA NCs enhance M2 macrophages by increasing the mammalian target of rapamycin (mTOR), and inhibit M1 macrophages by reducing hypoxia-inducible factor-1α (HIF-1α). Overall, this study shows that ES100-PIP/GA NCs have synergistic immunotherapy capabilities with macrophage regulation, which offers a promising blueprint for the oral delivery of multicomponent drugs in UC therapy.

Low-Cost Hydrogen Production from Alkaline/Seawater over a Single-Step Synthesis of Mo3 Se4 -NiSe Core-Shell Nanowire Arrays

The rational design and steering of earth-abundant, efficient, and stable electrocatalysts for hydrogen generation is highly desirable but challenging with catalysts free of platinum group metals (PGMs). Mass production of high-purity hydrogen fuel from seawater electrolysis presents a transformative technology for sustainable alternatives. Here, a heterostructure of molybdenum selenide-nickel selenide (Mo3 Se4 -NiSe) core-shell nanowire arrays constructed on nickel foam by a single-step in situ hydrothermal process is reported. This tiered structure provides improved intrinsic activity and high electrical conductivity for efficient charge transfer and endows excellent hydrogen evolution reaction (HER) activity in alkaline and natural seawater conditions. The Mo3 Se4 -NiSe freestanding electrodes require small overpotentials of 84.4 and 166 mV to reach a current density of 10 mA cm-2 in alkaline and natural seawater electrolytes, respectively. It maintains an impressive balance between electrocatalytic activity and stability. Experimental and theoretical calculations reveal that the Mo3 Se4 -NiSe interface provides abundant active sites for the HER process, which modulate the binding energies of adsorbed species and decrease the energetic barrier, providing a new route to design state-of-the-art, PGM-free catalysts for hydrogen production from alkaline and seawater electrolysis.

The progression of inorganic nanoparticles and natural products for inflammatory bowel disease

There is a growing body of evidence indicating a close association between inflammatory bowel disease (IBD) and disrupted intestinal homeostasis. Excessive production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), along with an increase in M1 proinflammatory macrophage infiltration during the activation of intestinal inflammation, plays a pivotal role in disrupting intestinal homeostasis in IBD. The overabundance of ROS/RNS can cause intestinal tissue damage and the disruption of crucial gut proteins, which ultimately compromises the integrity of the intestinal barrier. The proliferation of M1 macrophages contributes to an exaggerated immune response, further compromising the intestinal immune barrier. Currently, intestinal nanomaterials have gained widespread attention in the context of IBD due to their notable characteristics, including the ability to specifically target regions of interest, clear excess ROS/RNS, and mimic biological enzymes. In this review, we initially elucidated the gut microenvironment in IBD. Subsequently, we delineate therapeutic strategies involving two distinct types of nanomedicine, namely inorganic nanoparticles and natural product nanomaterials. Finally, we present a comprehensive overview of the promising prospects associated with the application of nanomedicine in future clinical settings for the treatment of IBD (graphic abstract). Different classes of nanomedicine are used to treat IBD. This review primarily elucidates the current etiology of inflammatory bowel disease and explores two prominent nanomaterial-based therapeutic approaches. First, it aims to eliminate excessive reactive oxygen species and reactive nitrogen species. Second, they focus on modulating the polarization of inflammatory macrophages and reducing the proportion of pro-inflammatory macrophages. Additionally, this article delves into the treatment of inflammatory bowel disease using inorganic metal nanomaterials and natural product nanomaterials.

Portulaca oleracea L. polysaccharide alleviates dextran sulfate sodium-induced ulcerative colitis by regulating intestinal homeostasis

Portulaca oleracea L. (purslane) is a vegetable that contains a variety of active compounds with nutritional properties and has the potential to treat ulcerative colitis (UC). However, the mechanisms underlying the effects of Portulaca oleracea L. polysaccharide (POP) in alleviating UC remain unclear. In this study, we prepared an aqueous extract of purslane and separated a fraction with molecular weight >10 kDa using membrane separation. This fraction was used to isolate POP. The effect of POP on gut microbiota and colon transcriptome in dextran sulfate sodium-induced UC model mice was evaluated. POP treatment reduced inflammation and oxidative stress imbalance in UC mice. In addition, POP improved the intestinal barrier and regulated intestinal homeostasis. Importantly, POP was found to regulate gut microbiota, maintain the levels of retinol and short-chain fatty acids in the gut, promote the proliferation and differentiation of B cells in the colon, and increase the expression of immunoglobulin A. These results provide novel insights into the role of POP in regulating intestinal homeostasis, which should guide further development of POP as a functional food.

Recent Development of Copper-Based Nanozymes for Biomedical Applications

Copper (Cu), an indispensable trace element within the human body, serving as an intrinsic constituent of numerous natural enzymes, carrying out vital biological functions. Furthermore, nanomaterials exhibiting enzyme-mimicking properties, commonly known as nanozymes, possess distinct advantages over their natural enzyme counterparts, including cost-effectiveness, enhanced stability, and adjustable performance. These advantageous attributes have captivated the attention of researchers, inspiring them to devise various Cu-based nanomaterials, such as copper oxide, Cu metal-organic framework, and CuS, and explore their potential in enzymatic catalysis. This comprehensive review encapsulates the most recent advancements in Cu-based nanozymes, illuminating their applications in the realm of biochemistry. Initially, it is delved into the emulation of typical enzyme types achieved by Cu-based nanomaterials. Subsequently, the latest breakthroughs concerning Cu-based nanozymes in biochemical sensing, bacterial inhibition, cancer therapy, and neurodegenerative diseases treatment is discussed. Within this segment, it is also explored the modulation of Cu-based nanozyme activity. Finally, a visionary outlook for the future development of Cu-based nanozymes is presented.

Colon-Targeted Release of Gel Microspheres Loaded with Antioxidative Fullerenol for Relieving Radiation-Induced Colon Injury and Regulating Intestinal Flora

Radiation-induced colitis is a serious clinical problem worldwide. However, the current treatment options for this condition have limited efficacy and can cause side effects. To address this issue, colon-targeted fullerenol@pectin@chitosan gel microspheres (FPCGMs) are developed, which can aggregate on colon tissue for a long time, scavenge free radicals generated in the process of radiation, and regulate intestinal flora to mitigate damage to colonic tissue. First, FPCGMs exhibit acid resistance and colon-targeted release properties, which reduce gastrointestinal exposure and extend the local colonic drug residence time. Second, fullerenol, which has a superior scavenging ability and chemical stability, reduces oxidative stress in colonic epithelial cells. Based on this, it is found that FPCGMs significantly reduce inflammation in colonic tissue, mitigated damage to tight junctions of colonic epithelial cells, and significantly relieved radiation-induced colitis in mice. Moreover, 16S ribosomal DNA (16S rDNA) sequencing results show that the composition of the intestinal flora is optimized after FPCGMs are utilized, indicating that the relative abundance of probiotics increases while harmful bacteria are inhibited. These findings suggest that it is a promising candidate for treating radiation-induced colitis.

Coal waste-derived synthesis of yellow oxidized graphene quantum dots with highly specific superoxide dismutase activity: characterization, kinetics, and biological studies

The disintegration of coal-based precursors for the scalable production of nanozymes relies on the fate of solvothermal pyrolysis. Herein, we report a novel economic and scalable strategy to fabricate yellow luminescent graphene quantum dots (YGQDs) by remediating unburnt coal waste (CW). The YGQDs (size: 7-8 nm; M.W: 3157.9 Da) were produced using in situ "anion-radical" assisted bond cleavage in water (within 8 h; at 121 °C) with yields of ∼87%. The presence of exposed surface and edge groups, such as COOH, C-O-C, and O-H, as structural defects accounted for its high fluorescence with εmax ∼530 nm at pH 7. Besides, these defects also acted as radical stabilizers, demonstrating prominent anti-oxidative activity of ∼4.5-fold higher than standard ascorbic acid (AA). In addition, the YGQDs showed high biocompatibility towards mammalian cells, with 500 μM of treatment dose showing <15% cell death. The YGQDs demonstrated specific superoxide dismutase (SOD) activity wherein 15 μM YGQDs equalled the activity of 1-unit biological SOD (bSOD), measured using the pyrogallol assay. The Km for YGQDs was ∼10-fold higher than that for bSOD. However, the YGQDs retained their SOD activity in harsh conditions like high temperatures or denaturing reactions, where the activity of bSOD is completely lost. The binding affinity of YGQDs for superoxide ions, measured from isothermal calorimetry (ITC) studies, was only 10-fold lower than that of bSOD (Kd of 586 nM vs. 57.3 nM). Further, the pre-treatment of YGQDs (∼10-25 μM) increased the cell survivability to >75-90% in three cell lines during ROS-mediated cell death, with the highest survivability being shown for C6-cells. Next, the ROS-induced apoptosis in C6-cells (model for neurodegenerative diseases study), wherein YGQDs uptake was confirmed by confocal microscopy, showed ∼5-fold apoptosis alleviation with only 5 μM pretreatment. The YGQDs also restored the expression of pro-inflammatory Th1 cytokines (TNF-α, IFN-γ, IL-6) and anti-inflammatory Th2 cytokines (IL-10) to their basal levels, with a net >3-fold change observed. This further explains the molecular mechanism for the antioxidant property of YGQDs. The high specific SOD activity associated with YGQDs may provide the cheapest alternative source for producing large-scale SOD-based nanozymes that can treat various oxidative stress-linked disorders/diseases.

Recent advances on emerging nanomaterials for diagnosis and treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic idiopathic inflammatory disorder that affects the entire gastrointestinal tract and is associated with an increased risk of colorectal cancer. Mainstream clinical testing methods are time-consuming, painful for patients, and insufficiently sensitive to detect early symptoms. Currently, there is no definitive cure for IBD, and frequent doses of medications with potentially severe side effects may affect patient response. In recent years, nanomaterials have demonstrated considerable potential for IBD management due to their diverse structures, composition, and physical and chemical properties. In this review, we provide an overview of the advances in nanomaterial-based diagnosis and treatment of IBD in recent five years. Multi-functional bio-nano platforms, including contrast agents, near-infrared (NIR) fluorescent probes, and bioactive substance detection agents have been developed for IBD diagnosis. Based on a series of pathogenic characteristics of IBD, the therapeutic strategies of antioxidant, anti-inflammatory, and intestinal microbiome regulation of IBD based on nanomaterials are systematically introduced. Finally, the future challenges and prospects in this field are presented to facilitate the development of diagnosis and treatment of IBD.

Emerging nanotherapeutic strategies targeting gut-X axis against diseases

Gut microbiota can coordinate with different tissues and organs to maintain human health, which derives the concept of the gut-X axis. Conversely, the dysbiosis of gut microbiota leads to the occurrence and development of various diseases, such as neurological diseases, liver diseases, and even cancers. Therefore, the modulation of gut microbiota offers new opportunities in the field of medicines. Antibiotics, probiotics or other treatments might restore unbalanced gut microbiota, which effects do not match what people have expected. Recently, nanomedicines with the high targeting ability and reduced toxicity make them an appreciative choice for relieving disease through targeting gut-X axis. Considering this paradigm-setting trend, the current review summarizes the advancements in gut microbiota and its related nanomedicines. Specifically, this article introduces the immunological effects of gut microbiota, summarizes the gut-X axis-associated diseases, and highlights the nanotherapeutics-mediated treatment via remolding the gut-X axis. Moreover, this review also discusses the challenges in studies related to nanomedicines targeting the gut microbiota and offers the future perspective, thereby aiming at charting a course toward clinic.

Cyclosporine A-Encapsulated pH/ROS Dual-Responsive Nanoformulations for the Targeted Treatment of Colitis in Mice

Inflammatory bowel disease (IBD) is a frequently occurring disease that seriously influences the patient's quality of life. To decrease adverse effects and improve efficacy of therapeutics, nanomedicines have been widely used to treat IBD. However, how to thoroughly release payloads under an inflammatory microenvironment and synergistic therapy of IBD need to be further investigated. To address this issue, cyclosporine A (CsA)-loaded, folic acid (FA)-modified, pH and reactive oxygen species (ROS) dual-responsive nanoparticles (FA-CsA NPs) were fabricated using pH/ROS-responsive material as carrier. The prepared FA-CsA NPs had spherical shape and uniform size distribution and could smartly release their payloads under acid and/or ROS microenvironment. In vitro experiments demonstrated that FA-CsA NPs can be effectively internalized by activated macrophages, and the internalized NPs could down-regulate the expression of proinflammatory cytokines compared to free drug or nontargeted NPs. In vivo experiments verified that FA-CsA NPs significantly accumulated at inflammatory colon tissues and the accumulated NPs obviously improved the symptoms of colitis in mice without obvious adverse effects. In conclusion, our results provided a candidate for the targeted treatment of IBD.

Recent Advances in Nanozyme-Based Materials for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a type of chronic inflammatory disorder that interferes with the patient's lifestyle and, in extreme situations, can be deadly. Fortunately, with the ever-deepening understanding of the pathological cause of IBD, recent studies using nanozyme-based materials have indicated the potential toward effective IBD treatment. In this review, the recent advancement of nanozymes for the treatment of enteritis is summarized from the perspectives of the structural design of nanozyme-based materials and therapeutic strategies, intending to serve as a reference to produce effective nanozymes for moderating inflammation in the future. Last but not least, the potential and current restrictions for using nanozymes in IBD will also be discussed. In short, this review may provide a guidance for the development of innovative enzyme-mimetic nanomaterials that offer a novel and efficient approach toward the effective treatment of IBD.

Integration of MyD88 inhibitor into mesoporous cerium oxide nanozymes-based targeted delivery platform for enhancing treatment of ulcerative colitis

Excessive reactive oxygen species (ROS) and stressed inflammatory response are major characteristics of ulcerative colitis, which cause disease progression and aggravation. Herein, a novel mesoporous cerium oxide nanozymes (MCN) was designed and then loaded with Myeloid differentiation factor-88 (MyD88) inhibitor for synergistic treatment of colitis by scavenging ROS and regulating inflammation. This innovative MCN with average particle size of 200.7 nm, specific surface area of 119.78 m2/g and mesopores of 4.47 nm not only exhibited excellent SOD-like and CAT-like activities to scavenge ROS but also could act as a carrier to load MyD88 inhibitor, TJ-M2010-5, (abbreviated as TJ-5) into their mesopores, achieving the effect of 'two birds with one stone'. Besides, the modification of dextran sulfate sodium (TJ-5/MCN/DSS) increased the internalization of nanozymes into activated macrophages and enhanced in vitro anti-inflammatory ability. To enhance colon targeting, we coated TJ-5/MCN/DSS with the enteric material Eudragit S100, preventing premature release or absorption of the drug in the gastrointestinal tract after oral administration. The results demonstrated that TJ-5/MCN/DSS/Eudragit not only achieved delayed drug release and improved colon targeting but also exhibited optimal therapeutic efficacy in colitis mice. Mechanistically, the MCN-mediated ROS scavenging and TJ-5-mediated MyD88 blockade synergistically inhibited the NF-κB signaling pathway, thereby reducing the inflammatory response. Importantly, TJ-5/MCN/DSS/Eudragit did not induce systemic toxicity. In conclusion, our work not only presents a novel carrier capable of scavenging ROS but also provides proof of concept for the synergistic treatment of colitis using this carrier in combination with MyD88 inhibitors. This study proposes a safe and efficient strategy for targeting ROS-associated inflammation.

New Insight into the Potential Protective Function of Sulforaphene against ROS-Mediated Oxidative Stress Damage In Vitro and In Vivo

Sulforaphene (SFE) is a kind of isothiocyanate isolated from radish seeds that can prevent free-radical-induced diseases. In this study, we investigated the protective effect of SFE on oxidative-stress-induced damage and its molecular mechanism in vitro and in vivo. The results of cell experiments show that SFE can alleviate D-gal-induced cytotoxicity, promote cell cycle transformation by inhibiting the production of reactive oxygen species (ROS) and cell apoptosis, and show a protective effect on cells with H2O2-induced oxidative damage. Furthermore, the results of mice experiments show that SFE can alleviate D-galactose-induced kidney damage by inhibiting ROS, malondialdehyde (MDA), and 4-hydroxyalkenals (4-HNE) production; protect the kidney against oxidative stress-induced damage by increasing antioxidant enzyme activity and upregulating the Nrf2 signaling pathway; and inhibit the activity of pro-inflammatory factors by downregulating the expression of Toll-like receptor 4 (TLR4)-mediated inflammatory response. In conclusion, this research shows that SFE has antioxidant effects, providing a new perspective for studying the anti-aging properties of natural compounds.

Momordica charantia-Derived Extracellular Vesicles Provide Antioxidant Protection in Ulcerative Colitis

Plant-derived extracellular vesicles are functional nanovesicles that have significant applications in both disease prevention and treatment, as well as for use as drug carriers. Momordica charantia is a widely consumed food that has both medicinal and nutritional properties and has shown intervention in diabetes and inflammation caused by oxidative damage. In this study, Momordica charantia-derived extracellular vesicles (MCEVs) were extracted and demonstrated to have excellent antioxidant activity by characterization, lipid composition analysis, protein domain analysis, and in vitro antioxidant measurement. In addition, in vivo studies indicated that the MCEVs could restore ulcerative colitis by regulating oxidation and inflammatory factors. Therefore, the antioxidant properties of MCEVs may be important in protecting the colon from inflammation, which provides new insights into the application of MCEVs as drugs or vectors for intervention in ulcerative colitis.

Oral hydrogel nanoemulsion co-delivery system treats inflammatory bowel disease via anti-inflammatory and promoting intestinal mucosa repair

BACKGROUND

Due to oral nano-delivery systems for the treatment of inflammatory bowel disease (IBD) are often failed to accumulated to the colonic site and could not achieve controlled drug release, it's urgent to develop a microenvironment responsive drug delivery to improve therapy efficacy. Inflammation at the IBD site is mainly mediated by macrophages, which are the key effector cells. Excessive inflammation leads to oxidative stress and intestinal mucosal damage. The use of curcumin (CUR) and emodin (EMO) together for the treatment of IBD is promising due to their respective anti-inflammatory and intestinal mucosal repair effects. In view of the pH gradient environment of gastrointestinal tract, here we prepared pH-responsive sodium alginate (SA) hydrogel-coated nanoemulsions to co-deliver CUR and EMO (CUR/EMO NE@SA) to achieve controlled drug release and specifically target macrophages of the colon.

RESULTS

In this study, a pH-responsive CUR/EMO NE@SA was successfully developed, in which the CUR/EMO NE was loaded by chitosan and further crosslinked with sodium alginate. CUR/EMO NE@SA had a pH-responsive property and could achieve controlled drug release in the colon. The preparation could significantly alleviate and improve the colon inflammatory microenvironment by decreasing TNF-α and IL-6 expression, increasing IL-10 expression, scavenging reactive oxygen species in macrophages, and by ameliorating the restoration of intestinal mucosal tight junction protein expression. Furthermore, we revealed the molecular mechanism of the preparation for IBD treatment, which might due to the CUR and EMO synergic inhibition of NF-κB to improve the pro-inflammatory microenvironment. Our study provides a new IBD therapy strategy via synergically inhibiting inflammatory, repairing mucosal and clearing ROS by pH-sensitive hydrogel-encapsulated nanoemulsion drug delivery system, which might be developed for other chronic inflammatory disease treatment.

CONCLUSIONS

It's suggested that pH-sensitive hydrogel-coated nanoemulsion-based codelivery systems are a promising combinatorial platform in IBD.

Protective Effects of Different Molecular Weights of Purslane (Portulaca oleracea L.) Aqueous Extract on DSS-Induced Ulcerative Colitis in Mice

Purslane, a common wild vegetable, contains active substances with various biological functions. However, its effects have been under-investigated in ulcerative colitis (UC). Therefore, this study investigated the therapeutic effects of purslane macromolecular (POEM) and small molecular extracts (POES) on dextran sulfate sodium (DSS)-induced UC in mice. Membrane separation was used to obtain extracts of different molecular weights, and their compositional differences were compared using liquid chromatography-mass spectrometry (LC/MS). POEM contained more proteins and polysaccharides, whereas POES contained more organic acids and alkaloids. These differences in composition were directly responsible for the different degrees of remission of the alleviated UC in model mice. POEM may alleviate UC by regulating the antioxidant capacity and the gut microbiota, whereas the major alleviatory effect of POES was primarily related to the regulation of antioxidant capacity. The POEM and POES effects identified in this study provide a theoretical basis for the development of purslane as a functional food.

Cyclosporine A-loaded colon-targeted oral nanomicelles self-assembly by galactosylated carboxymethyl chitosan for efficient ulcerative colitis therapy

An oral galactosylated carboxymethyl chitosan polymeric nanomicelles (Gal-N-CMCS NPs) embedded in chitosan-alginate hydrogel (CA-Gel) was developed to load cyclosporine A (CyA) as therapeutic agents against ulcerative colitis (UC). Galactose modified CMCS with macrophage targeting characteristic and CyA via a simple ultrasonication method to form Gal-N-CMCS/CyA NPs, and mixed CA-Gel to acquire the final formulation (Gal-N-CMCS/CyA Gel). The generated Gal-N-CMCS/CyA NPs displayed a desirable particle size (206.8 nm), negative surface charge (-19.5 mV), and high encapsulating efficiency (89.6%). The morphology and release profiles were also charactered by transmission electron microscope [1] and dialysis method, respectively. Strikingly, the mucus penetration of Gal-N-CMCS/CyA NPs exceeded 90% within 90 min. The Gal-N-CMCS NPs internalized by macrophages were 3.3-fold higher than CMCS-N NPs, thereby, enhancing the anti-inflammatory activities of NPs. Meanwhile, these NPs exhibited excellent biocompatibility, reduced the toxic effect of CyA, and targeting ability on inflammatory macrophages both in vitro and in vivo. Most importantly, in vivo studies revealed that CyA NPs could efficiently target the inflamed colon, remarkably alleviate inflammation, repair mucosal and reconstructed colonic epithelial barriers in UC mice induced by dextran sulfate sodium (DSS) via Toll-like receptor 4 -Nuclear factor kappa-B (TLR4-NF-κB) pathway. Our findings suggest that these high-performance and facilely fabricated Gal-N-CMCS/CyA NPs could be developed as a promising drug carrier for oral UC treatment.

Polydopamine-cladded montmorillonite micro-sheets as therapeutic platform repair the gut mucosal barrier of murine colitis through inhibiting oxidative stress

Montmorillonite (MMT), a layered aluminosilicate, has a mucosal nutrient effect and restores the gut barriers integrity. However, orally administrating MMT is not effective to combat the reactive oxygen species (ROS) and alleviate the acute inflammatory relapse for colitis patients. Herein, polydopamine-doped montmorillonite micro-sheets (PDA/MMT) have been developed as a therapeutic platform for colitis treatment. SEM and EDS analysis showed that dopamine monomer (DA) was easily polymerized in alkaline condition and polydopamine (PDA) was uniformly cladded on the surface of MMT micro-sheets. The depositing amount of PDA was reaching to 2.06 ​± ​0.08%. Moreover, in vitro fluorescence probes experiments showed that PDA/MMT presented the broad spectra of scavenging various ROS sources including •OH, •O^2-, and H₂O₂. Meanwhile, the intracellular ROS of Rosup/H₂O₂ treated Caco-2 ​cell was also effectively scavenged by PDA/MMT, which resulted in the obvious improvement of the cell viability under oxidative stress. Moreover, most of orally administrated PDA/MMT was transited to the gut and form a protective film on the diseased colon. PDA/MMT exhibited the obvious therapeutic effect on DSS-induced ulcerative colitis mouse. Importantly, the gut mucosa of colitis mouse was well restored after PDA/MMT treatment. Moreover, the colonic inflammation was significantly alleviated and the goblet cells were obliviously recovered. The therapeutic mechanism of PDA/MMT was highly associated with inhibiting oxidative stress. Collectively, PDA/MMT micro-sheets as a therapeutic platform may provide a promising therapeutic strategy for UC treatment.

Bio-adhesive and ROS-scavenging hydrogel microspheres for targeted ulcerative colitis therapy

Ulcerative colitis (UC) as an important type of inflammatory bowel disease is a chronic disease characterized by intestinal dyshomeostasis. The UC treatment is challenged by the insufficiency of drug delivery and retention. Herein, we fabricated an intrarectal formulation of olsalazine (Olsa)-loaded hydrogel microspheres (LDKT/Olsa) with good bio-adhesiveness and reactive oxygen species (ROS)-scavenging ability to enhance drug retention and therapeutic effect. Low methoxy pectin-dopamine conjugate/konjac glucomannan composite hydrogel microspheres (LDKT) with a size ranging from 10 to 100 μm were prepared by using Zn²⁺ and ROS-sensitive thioketal as crosslinkers. Upon intrarectal administration, the negatively charged and dopamine-functionalized hydrogel microspheres efficiently adhered to cationic surface of inflammatory mucosa, scavenging ROS and releasing Zn²⁺ and Olsa for antibacterial and anti-inflammatory effects. In the dextran sodium sulfate (DSS)-induced mouse UC model, the microspheres significantly reduced the levels of colonic ROS and pro-inflammatory cytokines, improved gut mucosal barrier integrity, and remarkably relieved colitis. Overall, the LDKT microspheres are promising carriers to deliver drugs for UC treatment.

Berberine promotes IGF2BP3 ubiquitination by TRIM21 to induce G1/S phase arrest in colorectal cancer cells

The increasing incidence of colorectal cancer (CRC) has become a major global public health burden. The natural drug Berberine (BBR) has shown potential in preventing CRC, and IGF2 mRNA binding protein 3 (IGF2BP3) may be a target of BBR. This study aims to investigate the mechanisms of BBR acting on IGF2BP3 to improve CRC. The results showed that IGF2BP3 played an important role in the development of CRC. BBR down-regulated IGF2BP3 expression and inhibited CRC growth in mice. Cell thermodynamic stability analysis (CETSA) and drug affinity responsive target stability (DARTS) analysis showed BBR may bind to IGF2BP3. BBR may induce structural changes in IGF2BP3 and decrease its protein stability in cytoplasm. The results from Co-Immunoprecipitation (Co-IP) suggested that BBR promoted the ubiquitination of IGF2BP3 by tripartite motif-containing protein 21 (TRIM21). Through RNA binding protein Immunoprecipitation (RIP) assay, it was found BBR inhibited the stabilization of CDK4/CCND1 mRNA by IGF2BP3 and promoted G1/S phase arrest in CRC cells. Overexpression of IGF2BP3 in vitro and in vivo attenuated the inhibition of CRC growth by BBR. This work demonstrated the potential of BBR targeting to IGF2BP3 in improving CRC and provided a new strategy for clinical treatment on CRC as well as novel anticancer drug design based on IGF2BP3 and TRIM21.

Electron transfer-based antioxidant nanozymes: Emerging therapeutics for inflammatory diseases

Inflammatory diseases are usually featured with relatively high level of reactive oxygen species (ROS). The excess ROS facilitate the polarization of microphages into proinflammatory M1 phenotype, and cause DNA damage, protein carbonylation, and lipid peroxidation, resulting in further deterioration of inflammatory diseases. Therefore, alleviating oxidative stress by ROS scavenging has been an effective strategy for reversing inflammation. Inspired by the natural antioxidant enzymes, electron transfer-based artificial antioxidant nanozymes have been emerging therapeutics for the treatment of inflammatory diseases. The present review starts with the basic knowledge of ROS and diseases, followed by summarizing the possible active centers for the preparation of antioxidant nanozymes. The strategies for the design of antioxidant nanozymes on the purpose of higher catalytic activity are provided, and the applications of the developed antioxidant nanozymes on the therapy of inflammatory diseases are discussed. A perspective is included for the design and applications of artificial antioxidant nanozymes in biomedicine as well.

Glutathione peroxidase-like nanozymes: mechanism, classification, and bioapplication

The field of nanozymes is developing rapidly. In particular, glutathione peroxidase (GPx)-like nanozymes, which catalytically reduce H₂O₂/organic hydroperoxides to H₂O/alcohols, have attracted considerable attention. GPx-like nanozymes are powerful antioxidant enzymes known to combat oxidative stress. They have broad applications, including cytoprotection, anti-inflammation, neuroprotection, tumor therapy, and anti-aging. Although much progress has been made, GPx-like nanozymes have not been well discussed or fully reviewed as other nanozymes. This review aims to summarize recent advances on GPx-like nanozymes from the vantage point of mechanism, classification, and bioapplication. Future prospects for advancing their design and application are also discussed.

The role and mechanism of flavonoid herbal natural products in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestine that presents clinically with abdominal pain, mucopurulent stools, and posterior urgency. The lesions of UC are mainly concentrated in the rectal and colonic mucosa and submucosa. For patients with mild to moderate UC, the best pharmacological treatment includes glucocorticoids, immunosuppressants, antibiotics, and biologics, but the long-term application can have serious toxic side effects. Currently, nearly 40% of UC patients are treated with herbal natural products in combination with traditional medications to reduce the incidence of toxic side effects. Flavonoid herbal natural products are the most widely distributed polyphenols in plants and fruits, which have certain antioxidant and anti-inflammatory activities. Flavonoid herbal natural products have achieved remarkable efficacy in the treatment of UC. The pharmacological mechanisms are related to anti-inflammation, promotion of mucosal healing, maintenance of intestinal immune homeostasis, and regulation of intestinal flora. In this paper, we summarize the flavonoid components of anti-ulcerative colitis and their mechanisms reported in the past 10 years, to provide a basis for rational clinical use and the development of new anti-ulcerative colitis drugs.