Zero-Valence Selenium-Enriched Prussian Blue Nanozymes Reconstruct Intestinal Barrier against Inflammatory Bowel Disease via Inhibiting Ferroptosis and T Cells Differentiation

Nanomedicines Targeting Ferroptosis to Treat Stress-Related Diseases

Ferroptosis, a unique form of regulated cell death driven by iron-dependent lethal lipid peroxidation, is implicated in various stress-related diseases like neurodegeneration, vasculopathy, and metabolic disturbance. Stress-related diseases encompass widespread medical disorders that are influenced or exacerbated by stress. These stressors can manifest in various organ or tissue systems and have significant implications for human overall health. Understanding ferroptosis in these diseases offers insights for therapeutic strategies targeting relevant pathways. This review explores ferroptosis mechanisms, its role in pathophysiology, its connection to stress-related diseases, and the potential of ferroptosis-targeted nanomedicines in treating conditions. This monograph also delves into the engineering of ferroptosis-targeted nanomedicines for tackling stress-related diseases, including cancer, cardia-cerebrovascular, neurodegenerative, metabolic and inflammatory diseases. Anyhow, nanotherapy targeting ferroptosis holds promise by both promoting and suppressing ferroptosis for managing stress-related diseases.

Clickable nanozyme enhances precise colonization of probiotics for ameliorating inflammatory bowel disease

Convincing evidence suggests that aberrant gut microbiota changes play a critical role in the progression and pathogenesis of inflammatory bowel disease (IBD). Probiotic therapeutic interventions targeting the microbiota may provide alternative avenues to treat IBD, but currently available probiotics often suffer from low intestinal colonization and limited targeting capability. Here, we developed azido (N3)-modified Prussian blue nanozyme (PB@N3) spatio-temporal guidance enhances the targeted colonization of probiotics to alleviate intestinal inflammation. First, clickable PB@N3 targets intestinal inflammation, simultaneously, it scavenges reactive oxygen species (ROS). Subsequently, utilizing "click" chemistry to spatio-temporally guide targeted colonization of dibenzocyclooctyne (DBCO)-modified Lactobacillus reuteri DSM 17938 (LR@DBCO). The "click" reaction between PB@N3 and LR@DBCO has excellent specificity and efficacy both in vivo and in vitro. Despite the complex physiological environment of IBD, "click" reaction can prolong the retention time of probiotics in the intestine. Dextran sulfate sodium (DSS)-induced colitis mice model, demonstrates that the combination of PB@N3 and LR@DBCO effectively mitigates levels of ROS, enhances the colonization of probiotics, modulates intestinal flora composition and function, regulates immune profiles, restores intestinal barrier function, and alleviates intestinal inflammation. Hence, PB@N3 spatio-temporal guidance enhances targeted colonization of LR@DBCO provides a promising medical treatment strategy for IBD.

Hydrogel-forming viscous liquid in response to ROS restores the gut mucosal barrier of colitis mice via regulating oxidative redox homeostasis

The disrupted oxidative redox homeostasis plays a critical role in the progress of ulcerative colitis (UC). Herein, hydrogel-forming viscous liquid (HSD) composed of cysteamine-grafted hyaluronic acid (HS) and superoxide dismutase (SOD) has been designed for UC. When the viscous HSD liquid was infused into colitis colon, SOD would convert the pathological superoxide (O2·-) to hydrogen peroxides (H2O2), which was subsequently scavenged by HS. Accordingly, the sol-gel transition of HSD was initiated by scavenging H2O2, enhancing its adhesion toward colitis colon. H2O2-treated HSD presented the higher storage modulus and stronger adhesion force toward porcine colon than the untreated HSD. Besides, H2O2-treated HSD presented the slower erosion profile in the colitis-mimicking medium (pH 3-5), while its rapid degradation was displayed in physiologic condition (pH7.4). The combination of pH-resistant erosion and ROS-responsive adhesion for HSD rendered it with the specifical retention on the inflamed colonic mucosa of DSS-induced colitis mice. Rectally administrating HSD could effectively hinder the body weight loss, reduce the disease activity index and improve the colonic shorting of DSS-induced colitis mice. Moreover, the pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) were substantially decreased, the colonic epitheliums were well rearranged and the tight junction proteins were greatly recovered after HSD treatment. Besides, HSD also modulated the gut flora, markedly augmenting the abundance of Firmicutes, Barnesiella and Lachnospiraceae. Moreover, HSD treatment could regulate oxidative redox homeostasis via activating Nrf2-HO-1 pathway to reduce ROS and malondialdehyde and upregulate antioxidant enzymes (SOD, GPx and GSH). Collectively, HSD might be a promising therapy for UC treatments. STATEMENT OF SIGNIFICANCE: Herein, a hydrogel-forming viscous liquid (HSD) was designed by cysteamine-grafted hyaluronic acid (HS) and superoxide dismutase (SOD) for UC treatments. When the viscous HSD liquid was infused into a colitis colon, SOD would convert the pathological superoxide to hydrogen peroxides (H2O2), which was subsequently scavenged by HS. Accordingly, the sol-gel transition of HSD was initiated by scavenging H2O2, enhancing its adhesion to the colitis colon. The colonic epitheliums of DSS-induced colitis mice were well rearranged and the tight junction proteins (Zonula-1 and Claudin-5) were greatly recovered after the HSD treatment. Moreover, the HSD treatment could regulate oxidative redox homeostasis via activating the Nrf2-HO-1 pathway to reduce ROS and malondialdehyde and upregulate antioxidant enzymes (SOD, GPx and GSH).

Scale-Up Preparation of Manganese-Iron Prussian Blue Nanozymes as Potent Oral Nanomedicines for Acute Ulcerative Colitis

Prussian blue (PB) nanozymes are demonstrated as effective therapeutics for ulcerative colitis (UC), yet an unmet practical challenge remains in the scalable production of these nanozymes and uncertainty over their efficacy. With a novel approach, a series of porous manganese-iron PB (MnPB) colloids, which are shown to be efficient scavengers for reactive oxygen species (ROS) including hydroxyl radical, superoxide anion, and hydrogen peroxide, are prepared. In vitro cellular experiments confirm the capability of the nanozyme to protect cells from ROS attack. In vivo, the administration of MnPB nanozyme through gavage at a dosage of 10 mg kg-1 per day for three doses in total potently ameliorates the pathological symptoms of acute UC in a murine model, resulting in mitigated inflammatory responses and improved viability rate. Significantly, the nanozyme produced at a large scale can be achieved at an unprecedented yield weighting ≈11 g per batch of reaction, demonstrating comparable anti-ROS activities and treatment efficacy to its small-scale counterpart. This work represents the first demonstration of the scale-up preparation of PB analog nanozymes for UC without compromising treatment efficacy, laying the foundation for further testing of these nanozymes on larger animals and promising clinical translation.

Ferroptosis in ulcerative colitis: Potential mechanisms and promising therapeutic targets

Ulcerative colitis (UC) is a complex immune-mediated chronic inflammatory bowel disease. It is mainly characterized by diffuse inflammation of the colonic and rectal mucosa with barrier function impairment. Identifying new biomarkers for the development of more effective UC therapies remains a pressing task for current research. Ferroptosis is a newly identified form of regulated cell death characterized by iron-dependent lipid peroxidation. As research deepens, ferroptosis has been demonstrated to be involved in the pathological processes of numerous diseases. A growing body of evidence suggests that the pathogenesis of UC is associated with ferroptosis, and the regulation of ferroptosis provides new opportunities for UC treatment. However, the specific mechanisms by which ferroptosis participates in the development of UC remain to be more fully and thoroughly investigated. Therefore, in this review, we focus on the research advances in the mechanism of ferroptosis in recent years and describe the potential role of ferroptosis in the pathogenesis of UC. In addition, we explore the underlying role of the crosslinked pathway between ferroptosis and other mechanisms such as macrophages, neutrophils, autophagy, endoplasmic reticulum stress, and gut microbiota in UC. Finally, we also summarize the potential compounds that may act as ferroptosis inhibitors in UC in the future.

Characterization of PANoptosis-related genes in Crohn's disease by integrated bioinformatics, machine learning and experiments

Currently, the biological understanding of Crohn's disease (CD) remains limited. PANoptosis is a revolutionary form of cell death reported to participate in numerous diseases, including CD. In our study, we aimed to uncover the roles of PANoptosis in CD. Differentially expressed PANoptosis-related genes (DE-PRGs) were identified by overlapping PANoptosis-related genes and differentially expressed genes between CD and normal samples in a combined microarray dataset. Three machine learning algorithms were adopted to detect hub DE-PRGs. To stratify the heterogeneity within CD patients, nonnegative matrix factorization clustering was conducted. In terms of immune landscape analysis, the "ssGSEA" method was applied. qRT-PCR was performed to examine the expression levels of the hub DE-PRGs in CD patients and colitis model mice. Ten hub DE-PRGs with satisfactory diagnostic performance were identified and validated: CD44, CIDEC, NDRG1, NUMA1, PEA15, RAG1, S100A8, S100A9, TIMP1 and XBP1. These genes displayed significant associations with certain immune cell types and CD-related genes. We also constructed gene‒microRNA, gene‒transcription factor and drug‒gene interaction networks. CD samples were classified into two PANoptosis patterns according to the expression levels of the hub DE-PRGs. Our results suggest that PANoptosis plays a nonnegligible role in CD by modulating the immune system and interacting with CD-related genes.

Targeting programmed cell death in inflammatory bowel disease through natural products: New insights from molecular mechanisms to targeted therapies

Inflammatory bowel disease (IBD) is an autoimmune disorder primarily characterized by intestinal inflammation and recurrent ulceration, leading to a compromised intestinal barrier and inflammatory infiltration. This disorder's pathogenesis is mainly attributed to extensive damage or death of intestinal epithelial cells, along with abnormal activation or impaired death regulation of immune cells and the release of various inflammatory factors, which contribute to the inflammatory environment in the intestines. Thus, maintaining intestinal homeostasis hinges on balancing the survival and functionality of various cell types. Programmed cell death (PCD) pathways, including apoptosis, pyroptosis, autophagy, ferroptosis, necroptosis, and neutrophil extracellular traps, are integral in the pathogenesis of IBD by mediating the death of intestinal epithelial and immune cells. Natural products derived from plants, fruits, and vegetables have shown potential in regulating PCD, offering preventive and therapeutic avenues for IBD. This article reviews the role of natural products in IBD treatment by focusing on targeting PCD pathways, opening new avenues for clinical IBD management.

Hyaluronic acid-functionalized DDAB/PLGA nanoparticles for improved oral delivery of magnolol in the treatment of ulcerative colitis

Dysfunction of the mucosal barrier as well as local inflammation are major challenges in the treatment of ulcerative colitis (UC). Mag, a natural compound derived from traditional Chinese medicine, has been shown to have anti-inflammatory and mucosal protection properties. However, its poor gastrointestinal stability as well as its insufficient accumulation in inflamed colonic lesions limit its potential use as an alternative therapeutic drug in UC. The present research involved the design and preparation of a hybrid nanoparticle system (LPNs) specifically targeting macrophages at the colonic site. This was achieved by electrostatically adsorbing HA onto positively charged lipid-polymer hybrid nanoparticles (HA-LPNs). The prepared HA-LPNs exhibited a rounded morphology and a narrow size distribution. In vitro, the anti-inflammatory efficacy of Mag-HA-LPNs (which control levels of the pro-inflammatory cytokines NO, IL-6 and TNF-α) was assessed in RAW 264.7 cells. Analysis by flow cytometry and fluorescence microscopy demonstrated increased cellular uptake through HA/CD44 interaction. As expected, Mag-HA-LPNs was found to effectively increased colon length and reduced DAI scores in DSS-treated mice. This effect was achieved by regulating the inflammatory cytokines level and promoting the restoration of the colonic mucosal barrier through increased expression of Claudin-1, ZO-1 and Occludin. In this study, we developed an efficient and user-friendly delivery method for the preparation of HA-functionalized PLGA nanoparticles, which are intended for oral delivery of Mag. The findings suggest that these HA-LPNs possess the potential to serve as a promising approach for direct drug delivery to the colon for effective treatment of UC.

The Role of the Trace Element Selenium in Inflammatory Bowel Disease

One set of chronic gastrointestinal disorders called inflammatory bowel disease (IBD) is defined by persistent, non-specific inflammation. Abdominal pain, hematochezia, diarrhea, and other symptoms are among its clinical signs. Currently, managing and treating IBD remains a significant challenge. Patients with IBD frequently have deficits in trace elements. Selenium (Se) is one of the necessary trace elements for normal organismal function. It has several regulatory effects, including anti-oxidation, anti-inflammatory, and defensive properties, via inducing the synthesis of selenoproteins. Patients with IBD have been shown to have lower Se levels in epidemiologic research studies. Several experimental models of IBD suggest that Se or selenoproteins play a key role in microinflammation. We discuss the relationship between Se and IBD in this review, with an emphasis on a summary of potential mechanisms of action and applications of Se in IBD.

2D Nanozymes Modulate Gut Microbiota and T-Cell Differentiation for Inflammatory Bowel Disease Management

Intestinal commensal microbiota dysbiosis and immune dysfunction are significant exacerbating factors in inflammatory bowel disease (IBD). To address these problems, Pluronic F-127-coated tungsten diselenide (WSe2 @F127) nanozymes are developed by simple liquid-phase exfoliation. The abundant valence transitions of elemental selenium (Se2- /Se4+ ) and tungsten (W4+ /W6+ ) enable the obtained WSe2 @F127 nanozymes to eliminate reactive oxygen/nitrogen species. In addition, the released tungsten ions are capable of inhibiting the proliferation of Escherichia coli. In a model of dextran sodium sulfate-induced colitis, WSe2 @F127 nanozymes modulate the gut microbiota by increasing the abundance of bacteria S24-7 and significantly reducing the abundance of Enterobacteriaceae. Moreover, WSe2 @F127 nanozymes inhibit T-cell differentiation and improve intestinal immune barrier function in a model of Crohn's disease. The WSe2 @F127 nanozymes effectively alleviate IBD by reducing oxidative stress damage, modulating intestinal microbial populations, and remodeling the immune barrier.

Tunable Sulfated Alginate-based Hydrogel Platform with enhanced anti-inflammatory and antioxidant capacity for promoting burn wound repair

Amidst progressive advancements in tissue engineering, there has been a significant enhancement in the efficacy of anti-inflammatory hydrogel dressings, addressing a myriad of clinical challenges on wound healing. A frequent complication during the initial stages of deep second-degree burn wound healing is the onset of an inflammatory storm, typically occurring without effective intervention. This event disrupts normal biological healing sequences, leading to undesirable regression. In response, we have customized a tunable, multidimensional anti-inflammatory hydrogel platform based on sulfated alginates (Algs), loaded with Prussian blue (PB) nanozymes. This platform competently eliminates surplus reactive oxygen species (ROS) present in the wound bed. Algs, functioning as a mimic of sulfated glycosaminoglycans (including heparin, heparan sulfate, and chondroitin sulfate) in the extracellular matrices (ECM), demonstrate a high affinity towards inflammatory chemokines such as interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1). This affinity effectively impedes the infiltration of inflammatory cells into the wound. Concurrently, Algs markedly modulate the macrophage phenotype transition from M1 to M2. Ultimately, our potent anti-inflammatory hydrogels, which strategically target inflammatory chemokines, M1 macrophages, and ROS, successfully attenuate dysregulated hyperinflammation in wound sites. Precise immunomodulation administered to deep second-degree burn wounds in mice has demonstrated promotion of neovascular maturation, granulation tissue formation, collagen deposition, and wound closure. Our biomimetic hydrogels, therefore, represent a significant expansion in the repertoire of anti-inflammatory strategies available for clinical practice.

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

Ulcerative colitis (UC) is a high incidence disease worldwide and clinically presents as relapsing and incurable inflammation of the colon. Bilirubin (BR), a natural antioxidant with significant anti-colitic effects, is utilized in preclinical studies as an intestinal disease therapy. Due to their water-insolubility, the design of BR-based agents usually involves complicated chemosynthetic processes, introducing various uncertainties in BR development. After screening numerous materials, it is identified that chondroitin sulfate can efficiently mediate the construction of BR self-assembled nanomedicine (BSNM) via intermolecular hydrogen bonds between dense sulfate and carboxyl of chondroitin sulfate and imino groups of BR. BSNM exhibits pH sensitivity and reactive oxygen species responsiveness, enabling targeted delivery to the colon. After oral administration, BSNM significantly inhibits colonic fibrosis and apoptosis of colon and goblet cells; it also reduces the expression of inflammatory cytokines. Moreover, BSNM maintains the normal level of zonula occludens-1 and occludin to sustain the integrity of intestinal barrier, regulates the macrophage polarization from M1 to M2 type, and promotes the ecological recovery of intestinal flora. Collectively, the work provides a colon-targeted and transformable BSNM that is simple to prepare and is useful as an efficient targeted UC therapy.

Recent Development and Application of "Nanozyme" Artificial Enzymes-A Review

Nanozymes represent a category of nano-biomaterial artificial enzymes distinguished by their remarkable catalytic potency, stability, cost-effectiveness, biocompatibility, and degradability. These attributes position them as premier biomaterials with extensive applicability across medical, industrial, technological, and biological domains. Following the discovery of ferromagnetic nanoparticles with peroxidase-mimicking capabilities, extensive research endeavors have been dedicated to advancing nanozyme utilization. Their capacity to emulate the functions of natural enzymes has captivated researchers, prompting in-depth investigations into their attributes and potential applications. This exploration has yielded insights and innovations in various areas, including detection mechanisms, biosensing techniques, and device development. Nanozymes exhibit diverse compositions, sizes, and forms, resembling molecular entities such as proteins and tissue-based glucose. Their rapid impact on the body necessitates a comprehensive understanding of their intricate interplay. As each day witnesses the emergence of novel methodologies and technologies, the integration of nanozymes continues to surge, promising enhanced comprehension in the times ahead. This review centers on the expansive deployment and advancement of nanozyme materials, encompassing biomedical, biotechnological, and environmental contexts.

Prussian blue nanozymes: progress, challenges, and opportunities

Prussian Blue Nanozymes (PBNZs) have emerged as highly efficient agents for reactive oxygen species (ROS) elimination, owing to their multiple enzyme-like properties encompassing catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities. As a functional nanomaterial mimicking enzyme, PBNZs not only surmount the limitations of natural enzymes, such as instability and high manufacturing costs, but also exhibit superior stability, tunable activity, low storage expenses, and remarkable reusability. Consequently, PBNZs have gained significant attention in diverse biomedical applications, including disease diagnosis and therapy. Over the past decade, propelled by advancements in catalysis science, biotechnology, computational science, and nanotechnology, PBNZs have witnessed remarkable progress in the exploration of their enzymatic activities, elucidation of catalytic mechanisms, and wide-ranging applications. This comprehensive review aims to provide a systematic overview of the discovery and catalytic mechanisms of PBNZ, along with the strategies employed to modulate their multiple enzyme-like activities. Furthermore, we extensively survey the recent advancements in utilizing PBNZs for scavenging ROS in various biomedical applications. Lastly, we analyze the existing challenges of translating PBNZs into therapeutic agents for clinical use and outline future research directions in this field. By presenting a comprehensive synopsis of the current state of knowledge, this review seeks to contribute to a deeper understanding of the immense potential of PBNZs as an innovative therapeutic agent in biomedicine.

Physiological Benefits of Novel Selenium Delivery via Nanoparticles

Dietary selenium (Se) intake within the physiological range is critical to maintain various biological functions, including antioxidant defence, redox homeostasis, growth, reproduction, immunity, and thyroid hormone production. Chemical forms of dietary Se are diverse, including organic Se (selenomethionine, selenocysteine, and selenium-methyl-selenocysteine) and inorganic Se (selenate and selenite). Previous studies have largely investigated and compared the health impacts of dietary Se on agricultural stock and humans, where dietary Se has shown various benefits, including enhanced growth performance, immune functions, and nutritional quality of meats, with reduced oxidative stress and inflammation, and finally enhanced thyroid health and fertility in humans. The emergence of nanoparticles presents a novel and innovative technology. Notably, Se in the form of nanoparticles (SeNPs) has lower toxicity, higher bioavailability, lower excretion in animals, and is linked to more powerful and superior biological activities (at a comparable Se dose) than traditional chemical forms of dietary Se. As a result, the development of tailored SeNPs for their use in intensive agriculture and as candidate for therapeutic drugs for human pathologies is now being actively explored. This review highlights the biological impacts of SeNPs on growth and reproductive performances, their role in modulating heat and oxidative stress and inflammation and the varying modes of synthesis of SeNPs.