In situ growth of nano-antioxidants on cellular vesicles for efficient reactive oxygen species elimination in acute inflammatory diseases

Engineered Turmeric-Derived Nanovesicles for Ulcerative Colitis Therapy by Attenuating Oxidative Stress and Alleviating Inflammation

Inflammation and oxidative stress are important features of traumatic ulcerative colitis (UC). Turmeric has been used as a dietary and functional ingredient for its potent anti-inflammatory effects in UC therapy. However, its practical effectiveness is hindered by limited reactive oxygen species (ROS) elimination properties. To address this, we constructed a unique treatment agent by growing cerium oxide (CeO2) nanocrystals on the membranes of turmeric-derived nanovesicles (TNVs), named as TNV-Ce. The resulted TNV-Ce could suppress inflammation and exhibit exceptional ROS-scavenging activity, which was validated both in lipopolysaccharide-induced macrophages and dextran sulfate sodium salt-induced chronic colitis mouse model. Following oral administration, TNV-Ce significantly accumulated at inflamed sites, effectively eliminating ROS and inhibiting pro-inflammatory cytokines for synergistic action against UC.

Co-Delivery of Morphologically Switchable Au Nanowire and Hemoglobin-Resveratrol Nanoparticles in the Microneedle for Diabetic Wound Healing Therapy

Diabetic wounds are a common complication of diabetes and pose a significant threat to human health. High glucose concentration in the wound remains a major obstacle, necessitating effective strategies to achieve sustained glucose consumption for synergistic diabetic wound therapy. In this study, an Au-based nanomaterial is developed that can adjust its morphology in different therapeutic processes. The prepared Au nanowire (ANW) can be converted into Au nanospheres (AS) under ultrasonic conditions by adjusting the amount of polyethylene glycol (PEG) on its surface for convenient delivery. Intriguingly, AS is depolymerized into ANW again in the wound area, prolonging the retention time, and ensuring continuous consumption of glucose. After constructing the morphologically switchable Au nanowire, a polyvinyl alcohol (PVA) is applied it to microneedle and co-delivered it with hemoglobin (Hb)-resveratrol (RES) nanoparticles for synergistic diabetic wound therapy. In a streptozotocin (STZ)-induced diabetic mouse model, the microneedle degraded gradually, and the Hb-RES nanoparticles synergistically ameliorated hypoxia, scavenged ROS, and inhibited macrophage differentiation into pro-inflammatory M1 phenotypes. During this process, ANW continuously catalyzed glucose through its inherent glucose oxidase activity. Thus, this study provides novel insights into the long-term management of glucose concentration during synergistic diabetic wound healing.

Polystyrene Microplastics Can Aggravate the Damage of the Intestinal Microenvironment Caused by Okadaic Acid: A Prevalent Algal Toxin

As emerging contaminants, microplastics (MPs) may pose a threat to human health. Their co-exposure with the widespread phycotoxin okadaic acid (OA), a marine toxin known to cause gastrointestinal toxicity, may exacerbate health risk and raise public safety concern. In this study, the toxicity mechanisms of MPs and OA on intestinal microenvironment was explored using human Caco-2 cells as the model, which was combined with an in vitro fecal fermentation experiment. Our results showed that co-exposure to MPs (80 μg/mL) and OA (20 ng/mL) significantly decreased cell viability, increased intracellular reactive oxygen species (ROS) production, elevated lactate dehydrogenase release, impaired ABC transporter activity, promoted OA accumulation, and triggered inflammatory response compared to the control, MPs, and OA groups, indicating that co-exposure directly compromises intestinal epithelial integrity. In vitro fermentation experiments revealed that co-exposure disrupted gut microbial composition, decreasing the relative abundance of some bacteria, such as Parasutterella and Adlercreutzia, while increasing opportunistic pathogens, such as Escherichia-Shigella, increased. These findings provide new insights into the impact and underlying mechanisms of MPs and OA co-exposure on intestinal homeostasis, highlighting the potential health risks associated with MPs.

TA-V Nanozymes with Acid Resistance Capabilities Effectively Target and Alleviate Ulcerative Colitis Lesions via Oral Delivery

As one of the most common inflammatory bowel diseases (IBDs), ulcerative colitis (UC) has become a rising global health issue that affects people's quality of life. Conventional therapeutic drugs have low bioavailability and may cause serious side effects due to their lack of acidic resistance and lesion-targeting capabilities. The development of novel nanomedicines to overcome these problems is urgently needed. Nanozymes have attracted attention because of their excellent catalytic efficiency in various harsh environments. In this study, tannic acid-vanadium (TA-V) nanozymes with multienzymatic and excellent antioxidant abilities, which exhibit acidic resistance and a negative surface charge, were successfully developed. All these characteristics make it possible that these nanozymes are not easily decomposed by gastric acid and can effectively accumulate in colitis lesions with a positive charge through oral delivery. In vitro and in vivo experiments further demonstrated the excellent prophylactic and therapeutic value of these compounds in the treatment of UC by scavenging reactive oxygen/nitrogen species (ROS/RNS) and mitigating the oxidative stress environment, thus downregulating the levels of the proinflammatory cytokines IL-1β, IL-6, and TNF-α. Furthermore, TA-V also showed excellent biosafety and biocompatibility without causing obvious damage to the main organs. This work provides novel preventative and therapeutic TA-V nanozymes that might have potential clinical applications in UC treatment.

"Bioactive" Therapeutic Contact Lens Triggered by Biomimetic Chiral Helical Nanoarchitectonics for Rapid Corneal Repair

Consistent corneal epithelial injury would cause chronic inflammation, neovascularization, and even corneal scarring, resulting in vision loss. Rapid repair is crucial for treatment, within which the use of therapeutic contact lenses presents great promise. A great challenge is how to achieve rapid repair of severely deficient corneal epithelium and regulation of the oxidative stress environment simultaneously. Herein, a "bioactive" therapeutic contact lens, mimicking the layered helical structure of the native cornea, is designed based on the assembly of cellulose nanocrystals (CNCs) inside poly(hydroxyethyl methacrylate) (PHEMA) with CeOx formed on the CNCs' surface (CeOx/CNC@CNC-PHEMA). The obtained CeOx/CNC@CNC-PHEMA hydrogel possesses a chiral helical structure that regulates the microenvironment, and the nanoscaled CeOx on the CNCs' surface (CeOx/CNC) acts as a reactive oxygen species (ROS) scavenger and triggers a "bioactive" therapeutic contact lens for rapid corneal repair. This hydrogel meets the conditions of a therapeutic contact lens, including high degree of transparency, excellent mechanical properties, great ROS-scavenging efficacy, and a significant enhancement of biocompatibility. Importantly, the adhesion and proliferation of human corneal epithelial cells on the CeOx/CNC@CNC-PHEMA hydrogels are successful. An in vitro corneal oxidative damage model and in vivo animal model of corneal injury experiments were conducted, and results revealed that the hydrogel realized rapid corneal epithelial cells migration with antioxidant, anti-inflammatory, and antineovascular effects, achieving modulation of the ocular surface microenvironment, evidencing a "bioactive" property of the hydrogel as a therapeutic contact lens. This biotopological hydrogel with a biomimetic corneal architecture has provided a rational strategy for rapid corneal repair.

Autophagosomes coated in situ with nanodots act as personalized cancer vaccines

Autophagosome cancer vaccines can promote cross-presentation of multiple tumour antigens and induce cross-reactive T cell responses. However, so far, there is no effective method for obtaining a highly immunogenic autophagosomal cancer vaccine because autophagosomes, once formed, quickly fuse with lysosomes and cannot easily escape from cells. Here we report a functional Ti2NX nanodot that caps the autophagosome membrane lipid phosphatidylinositol-4-phosphate, blocking the fusion of autophagosomes with lysosomes and producing stable nanodot-coated autophagosomes in tumours. The formed nanodot-coated autophagosomes can escape from cancer cells to lymph nodes, where they activate tumour-specific T cells. We show that our approach reduces tumour burden and provide long-term immune surveillance protection for cured mice. This work provides a method for the direct formation of personalized autophagosome-based cancer vaccines in vivo, offering a promising strategy for tumour treatment.

Reactive oxygen species-scavenging biomaterials for neural regenerative medicine

Reactive oxygen species (ROS) are natural by-products of oxygen metabolism. As signaling molecules, ROS can regulate various physiological processes in the body. However excessive ROS may be a major cause of inflammatory diseases. In the field of neurological diseases, ROS cause neuronal apoptosis and neurodegeneration, which severely impede neuroregeneration. Currently, ROS-scavenging biomaterials are considered as a promising therapeutic strategy for neurological injuries due to their ability to scavenge excessive ROS at defects and modulate the oxidative stress microenvironment. This review provides an overview of the generation and sources of ROS, briefly describes the dangers of generating excessive ROS in nervous system diseases, and highlights the importance of scavenging excessive ROS for neuroregeneration. We have classified ROS-scavenging biomaterials into three categories based on the different mechanisms of ROS clearance. The applications of ROS-responsive biomaterials for neurological diseases, such as spinal cord injury, brain injury, and peripheral nerve injury, are also discussed. Our review contributes to the development of ROS-scavenging biomaterials in the field of neural regeneration.

In Situ Crystallized Ceria-Vesicle Nanohybrid Therapeutic for Effective Treatment of Inflammatory Intraocular Disease

Posterior uveitis is a leading cause of vision impairment and blindness globally due to its detrimental effects on the choroid and retina. The condition is worsened by oxidative stress, which heightens inflammation and perpetuates a cycle of damage that current treatments only temporarily relieve. To address this, a novel treatment involving the in situ crystallization of ultrasmall cerium oxide nanoparticles (≈3 nm) on mesenchymal stem cell (MSC) extracellular vesicles (EVs) for the management of primed mycobacterial uveitis (PMU) is developed. This nanohybrid leverages the individual and synergistic effects of its components for a comprehensive therapeutic approach. The cerium oxide nanoparticles act as a nanozyme to reduce inflammation and scavenge excessive reactive oxygen species (ROS), while the MSC EVs, with their biocompatibility, modulate inflammatory cell infiltration and alleviate tissue damage. This synergistic system offers a promising new treatment strategy for ocular diseases characterized by oxidative stress and inflammation.

C17-Labdane diterpenoid alkaloids bearing a rare skeleton with anti-inflammatory and anti-oxidant activities from Forsythia suspensa

Two undescribed C17-Labdane diterpenoid alkaloids, named forsylinfenines A and B (1-2), attributable to a rare 4,4,10,13-tetramethyl-1(2),3(4),5(10),6(7)-octahydrobenzo[f]quinolin skeleton, along with three known β-carboline-type alkaloids (3-5), were isolated. The chemical structures including absolute configurations of two undescribed compounds were established by means of integrated spectroscopic techniques and electronic circular dichroism (ECD) calculations. In addition, a plausible biosynthetic pathway for the formation of compounds 1 and 2 was proposed. In vitro, five alkaloids (1-5), especially two undescribed alkaloids with rare skeleton (1-2), exhibited significant anti-inflammatory activities due to inhibiting the release of TNF-α, IL-6, and IL-1β, as well as effective anti-oxidant activities owing to preventing the production of ROS in the LPS-induced RAW264.7 cells.

An Asymmetric Bacterial Cellulose Membrane Incorporating CuPt Nanozymes and Curcumin for Accelerating Wound Healing

Damaged skin compromises its ability to effectively prevent the invasion of harmful bacteria into the tissue, leading to bacterial infection of the wound and hindering the healing process. To address this challenge, we have developed a multifunctional asymmetric wound dressing (CuPt-Cur-ABC) that effectively addresses the lack of bactericidal activity and the release of active ingredients in conventional bacterial cellulose (BC), which can be employed to create a barrier of defense between the wound and its surrounding environment. Compared with BC, asymmetric bacterial cellulose (ABC) used starch as a pore-causing agent, forming holes of different sizes at the top and bottom, which enhanced the ability of ABC to load and moderate-release drugs. First, as-synthesized CuPt nanozymes with an octopod nanoframe structure had multiple enzymatic activities including peroxidase-like, catalase-like, and glutathione peroxidase-like activities. Then, CuPt and curcumin (Cur) were loaded into ABC under ultrasound. Under 808 nm laser irradiation, the nanocomposites possessed good photothermal properties. So the photothermal therapy combined with chemodynamic therapy and inherent antibacterial performance of Cur achieved 99.3% and 99.6% in vitro bactericidal efficacy against Staphylococcus aureus and Escherichia coli, respectively. Moderate release of Cur can clear the excess reactive oxygen species and promote the polarization of macrophages toward the M2 type. In vivo experiments additionally confirmed that the constructed wound dressing achieved multiple functions, including effective antibacterial activity, reversing the inflammatory microenvironment, and promoting wound healing.

CeO2 In Situ Growth on Red Blood Cell Membranes: CQD Coating and Multipathway Alzheimer's Disease Therapy under NIR

Alzheimer's disease (AD) has a complex etiology and diverse pathological processes. The therapeutic effect of single-target drugs is limited, so simultaneous intervention of multiple targets is gradually becoming a new research trend. Critical stages in AD progression involve amyloid-β (Aβ) self-aggregation, metal-ion-triggered fibril formation, and elevated reactive oxygen species (ROS). Herein, red blood cell membranes (RBC) are used as templates for the in situ growth of cerium oxide (CeO2) nanocrystals. Then, carbon quantum dots (CQDs) are encapsulated to form nanocomposites (CQD-Ce-RBC). This strategy is combined with photothermal therapy (PTT) for AD therapy. The application of RBC enhances the materials' biocompatibility and improves immune evasion. RBC-grown CeO2, the first application in the field of AD, demonstrates outstanding antioxidant properties. CQD acts as a chelating agent for copper ions, which prevents the aggregation of Aβ. In addition, the thermal effect induced by near-infrared laser-induced CQD can break down Aβ fibers and improve the permeability of the blood-brain barrier. In vivo experiments on APP/PS1 mice demonstrate that CQD-Ce-RBC combined with PTT effectively clears cerebral amyloid deposits and significantly enhances learning and cognitive abilities, thereby retarding disease progression. This innovative multipathway approach under light-induced conditions holds promise for AD treatment.

Renal Clearable Nanodots-Engineered Erythrocytes with Enhanced Circulation and Tumor Accumulation for Photothermal Therapy of Hepatocellular Carcinoma

Living cell-mediated nanodelivery system is considered a promising candidate for targeted antitumor therapy; however, their use is restricted by the adverse interactions between carrier cells and nanocargos. Herein, a novel erythrocyte-based nanodelivery system is developed by assembling renal-clearable copper sulfide (CuS) nanodots on the outer membranes of erythrocytes via a lipid fusion approach, and demonstrate that it is an efficient photothermal platform against hepatocellular carcinoma. After intravenous injection of the nanodelivery system, CuS nanodots assembled on erythrocytes can be released from the system, accumulate in tumors in response to the high shear stress of bloodstream, and show excellent photothermal antitumor effect under the near infrared laser irradiation. Therefore, the erythrocyte-mediated nanodelivery system holds many advantages including prolonged blood circulation duration and enhanced tumor accumulation. Significantly, the elimination half-life of the nanodelivery system is 74.75 ± 8.77 h, which is much longer than that of nanodots (33.56 ± 2.36 h). Moreover, the other two kinds of nanodots can be well assembled onto erythrocytes to produce other erythrocyte-based hitchhiking platforms. Together, the findings promote not only the development of novel erythrocyte-based nanodelivery systems as potential platforms for tumor treatment but also their further clinical translation toward personalized healthcare.

Recent progress on engineered micro/nanomaterials mediated modulation of gut microbiota for treating inflammatory bowel disease

Inflammatory bowel disease (IBD) is a type of chronic recurrent inflammation disease that mainly includes Crohn's disease and ulcerative colitis. Currently, the treatments for IBD remain highly challenging, with clinical treatment drugs showing limited efficacy and adverse side effects. Thus, developing drug candidates with comprehensive therapeutic effects, high efficiency, and low toxicity is urgently needed. Recently, micro/nanomaterials have attracted considerable interest because of their bioavailability, multitarget and efficient effects on IBD. In addition, gut modulation plays a substantial role in restoring intestinal homeostasis. Therefore, efficient microbiota-based strategies modulating gut microenvironment have great potential in remarkably treating IBD. With the development of micro- and nanomaterials for the treatment of IBD and more in-depth studies of their therapeutic mechanisms, it has been found that these treatments also have a tendency to positively regulate the intestinal flora, resulting in an increase in the beneficial flora and a decrease in the level of pathogenic bacteria, thus regulating the composition of the intestinal flora to a normal state. In this review, we first present the interactions among the immune system, intestinal barrier, and gut microbiome. In addition, recent advances in administration routes and methods that positively arouse the regulation of intestinal flora for IBD using probiotics, prebiotics, and redox-active micro/nanomaterials have been reviewed. Finally, the key challenges and critical perspectives of gut microbiota-based micro/nanomaterial treatment are also discussed.

An Antioxidative and Active Shrinkage Hydrogel Integratedly Promotes Re-Epithelization and Skin Constriction for Enhancing Wound Closure

Delayed re-epithelization and weakened skin contractions are the two primary factors that hinder wound closure in large-scale acute or chronic wounds. However, effective strategies for targeting these two aspects concurrently are still lacking. Herein, an antioxidative active-shrinkage hydrogel (AHF@AS Gel) is constructed that can integratedly promote re-epithelization and skin constriction to accelerate large-scale acute and diabetic chronic wound closure. The AHF@AS Gel is encapsulated by antioxidative amino- and hydroxyl-modified C70 fullerene (AHF) and a thermosensitive active shrinkage hydrogel (AS Gel). Specifically, AHF relieves overactivated inflammation, prevents cellular apoptosis, and promotes fibroblast migration in vitro by reducing excessive reactive oxygen species (ROS). Notably, the AHF@AS Gel achieved ≈2.7-fold and ≈1.7-fold better re-epithelization in acute wounds and chronic diabetic wounds, respectively, significantly contributing to the promotion of wound closure. Using proteomic profiling and mechanistic studies, it is identified that the AHF@AS Gel efficiently promoted the transition of the inflammatory and proliferative phases to the remodeling phase. Notably, it is demonstrated that AS Gel alone activates the mechanosensitive epidermal growth factor receptor/Akt (EGFR/Akt) pathway and promotes cell proliferation. The antioxidative active shrinkage hydrogel offers a comprehensive strategy for acute wound and diabetic chronic wound closure via biochemistry regulation integrating with mechanical forces stimulation.

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.

Neuroprotective Effects of Microglial Membrane-Derived Biomimetic Particles for Spinal Cord Injury

Inhibition of oxidative stress and inflammatory responses caused by secondary injury following traumatic spinal cord injury (SCI) is an attractive strategy in treating traumatic SCI. However, the efficacy of drugs is severely limited owing to the poor penetration of the blood spinal cord barrier (BSCB). Here, inspired by cell chemotaxis and related chemokines production at the lesion sites of SCI, the microglial membrane is selected to construct a drug delivery system with the ability to cross the BSCB and target the lesions. PR@MM is prepared based on the assembly of polylactic-co-glycolic acid (PLGA) and resveratrol (RSV) followed by microglial membrane (MM) coating. Compared to that of the uncoated nanoparticles, the enrichment of PR@MM at the lesion sites of SCI increases, which is beneficial to achieve lesion targeting of RSV and exert therapeutic functions. Both in vitro and in vivo experiments demonstrate that PR@MM has the ability to scavenge reactive oxygen species and anti-inflammatory effects, which ultimately promotes the recovery of locomotory function after SCI. Therefore, this microglial membrane-based drug delivery system provides a promising biomimetic nanomedicine for targeted therapy for SCI.

Genetically Engineered Cellular Nanovesicle as Targeted DNase I Delivery System for the Clearance of Neutrophil Extracellular Traps in Acute Lung Injury

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) are prevalent critical illnesses with a high mortality rate among patients in intensive care units. Neutrophil extracellular traps (NETs) are implicated in the pathogenesis of ALI/ARDS and represent a promising therapeutic target. However, the clinical application of deoxyribonuclease I (DNase I), the only drug currently available to clear NETs, is limited due to the lack of precise and efficient delivery strategies. Therefore, targeted delivery of DNase I to the inflamed lung remains a critical issue to be addressed. Herein, a novel biomimetic DNase I delivery system is developed (DCNV) that employs genetically and bioorthogonally engineered cellular nanovesicles for pulmonary NETs clearance. The CXC motif chemokine receptor 2 overexpressed cellular nanovesicles can mimic the inflammatory chemotaxis of neutrophils in ALI/ARDS, leading to enhanced lung accumulation. Furthermore, DNase I immobilized through bioorthogonal chemistry exhibits remarkable enzymatic activity in NETs degradation, thus restraining inflammation and safeguarding lung tissue in the lipopolysaccharide-induced ALI murine model. Collectively, the findings present a groundbreaking proof-of-concept in the utilization of biomimetic cellular nanovesicles to deliver DNase I for treating ALI/ARDS. This innovative strategy may usher in a new era in the development of pharmacological interventions for various inflammation-related diseases.

Stem cell-derived hepatocyte therapy using versatile biomimetic nanozyme incorporated nanofiber-reinforced decellularized extracellular matrix hydrogels for the treatment of acute liver failure

Reactive oxygen species (ROS)-associated oxidative stress, inflammation storm, and massive hepatocyte necrosis are the typical manifestations of acute liver failure (ALF), therefore specific therapeutic interventions are essential for the devastating disease. Here, we developed a platform consisting of versatile biomimetic copper oxide nanozymes (Cu NZs)-loaded PLGA nanofibers (Cu NZs@PLGA nanofibers) and decellularized extracellular matrix (dECM) hydrogels for delivery of human adipose-derived mesenchymal stem/stromal cells-derived hepatocyte-like cells (hADMSCs-derived HLCs) (HLCs/Cu NZs@fiber/dECM). Cu NZs@PLGA nanofibers could conspicuously scavenge excessive ROS at the early stage of ALF, and reduce the massive accumulation of pro-inflammatory cytokines, herein efficiently preventing the deterioration of hepatocytes necrosis. Moreover, Cu NZs@PLGA nanofibers also exhibited a cytoprotection effect on the transplanted HLCs. Meanwhile, HLCs with hepatic-specific biofunctions and anti-inflammatory activity acted as a promising alternative cell source for ALF therapy. The dECM hydrogels further provided the desirable 3D environment and favorably improved the hepatic functions of HLCs. In addition, the pro-angiogenesis activity of Cu NZs@PLGA nanofibers also facilitated the integration of the whole implant with the host liver. Hence, HLCs/Cu NZs@fiber/dECM performed excellent synergistic therapeutic efficacy on ALF mice. This strategy using Cu NZs@PLGA nanofiber-reinforced dECM hydrogels for HLCs in situ delivery is a promising approach for ALF therapy and shows great potential for clinical translation.

Combining MSC Exosomes and Cerium Oxide Nanocrystals for Enhanced Dry Eye Syndrome Therapy

Dry eye syndrome (DES) is a prevalent ocular disorder involving diminishe·d tear production and increased tear evaporation, leading to ocular discomfort and potential surface damage. Inflammation and reactive oxygen species (ROS) have been implicated in the pathophysiology of DES. Inflammation is one core cause of the DES vicious cycle. Moreover, there are ROS that regulate inflammation in the cycle from the upstream, which leads to treatment failure in current therapies that merely target inflammation. In this study, we developed a novel therapeutic nanoparticle approach by growing cerium oxide (Ce) nanocrystals in situ on mesenchymal stem cell-derived exosomes (MSCExos), creating MSCExo-Ce. The combined properties of MSCExos and cerium oxide nanocrystals aim to target the "inflammation-ROS-injury" pathological mechanism in DES. We hypothesized that this approach would provide a new treatment option for patients with DES. Our analysis confirmed the successful in situ crystallization of cerium onto MSCExos, and MSCExo-Ce displayed excellent biocompatibility. In vitro and in vivo experiments have demonstrated that MSCExo-Ce promotes corneal cell growth, scavenges ROS, and more effectively suppresses inflammation compared with MSCExos alone. MSCExo-Ce also demonstrated the ability to alleviate DES symptoms and reverse pathological alterations at both the cellular and tissue levels. In conclusion, our findings highlight the potential of MSCExo-Ce as a promising therapeutic candidate for the treatment of DES.

MnO2 Coated Mesoporous PdPt Nanoprobes for Scavenging Reactive Oxygen Species and Solving Acetaminophen-Induced Liver Injury

As one of the most widely used drugs, acetaminophen, is the leading cause of acute liver injury. In addition, acetaminophen-induced liver injury (AILI) has a strong relationship with the overproduced reactive oxygen species, which can be effectively eliminated by nanozymes. To address these challenges, mesoporous PdPt@MnO2 nanoprobes (PPM NPs) mimicking peroxide, catalase, and superoxide dismutase-like properties are synthesized. They demonstrate nontoxicity, high colloidal stability, and exceptional reactive oxygen species (ROS)-scavenging ability. By scavenging excessive ROS, decreasing inflammatory cytokines, and inhibiting the recruitment and activation of monocyte/macrophage cells and neutrophils, the pathology mechanism of PPM NPs in AILI is confirmed. Moreover, PPM NPs' therapeutic effect and good biocompatibility may facilitate the clinical treatment of AILI.

Oral polyphenol-armored nanomedicine for targeted modulation of gut microbiota-brain interactions in colitis

Developing oral nanomedicines that suppress intestinal inflammation while modulating gut microbiota and brain interactions is essential for effectively treating inflammatory bowel disease. Here, we report an oral polyphenol-armored nanomedicine based on tumor necrosis factor-α (TNF-α)-small interfering RNA and gallic acid-mediated graphene quantum dot (GAGQD)-encapsulated bovine serum albumin nanoparticle, with a chitosan and tannin acid (CHI/TA) multilayer. Referred to "armor," the CHI/TA multilayer resists the harsh environment of the gastrointestinal tract and adheres to inflamed colon sites in a targeted manner. TA provides antioxidative stress and prebiotic activities that modulate the diverse gut microbiota. Moreover, GAGQD protected TNF-α-siRNA delivery. Unexpectedly, the armored nanomedicine suppressed hyperactive immune responses and modulated bacterial gut microbiota homeostasis in a mouse model of acute colitis. Notably, the armored nanomedicine alleviated anxiety- and depression-like behaviors and cognitive impairment in mice with colitis. This armor strategy sheds light on the effect of oral nanomedicines on bacterial gut microbiome-brain interactions.

Extracellular vesicles as potential biomarkers and treatment options for liver failure: A systematic review up to March 2022

INTRODUCTION

Extracellular vesicles (EVs) carrying functional cargoes are emerging as biomarkers and treatment strategies in multiple liver diseases. Nevertheless, the potential of EVs in liver failure remains indistinct. In this systematic review, we comprehensively analyzed the potential of EVs as biomarkers of liver failure and the therapeutic effects and possible mechanisms of EVs for liver failure.

METHODS

We conducted a systematic review by comprehensively searching the following electronic databases: PubMed, Web of Science, Embase and Cochrane Central Register of Controlled Trials from inception to March 2022. The used text words (synonyms and word variations) and database-specific subject headings included "Extracellular Vesicles", "Exosomes", "Liver Failure", "Liver Injury", etc.

RESULTS

A total of 1479 studies were identified. After removing 680 duplicate studies and 742 irrelevant studies, 57 studies were finally retained and analyzed. Fourteen studies revealed EVs with functional cargoes could be used to make the diagnosis of liver failure and provide clues for early warning and prognostic assessment of patients with liver failure. Forty-three studies confirmed the administration of EVs from different sources alleviated hepatic damage and improved survival through inhibiting inflammatory response, oxidative stress as well as apoptosis or promoting hepatocyte regeneration and autophagy.

CONCLUSIONS

EVs and their cargoes can be used not only as superior biomarkers of early warning, early diagnosis and prognostic assessments for liver failure, but also as potentially effective treatment options for liver failure. In the future, large-scale studies are urgently needed to verify the diagnostic, predictive and therapeutic value of EVs for liver failure.

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.

MSI2 deficiency in ILC3s attenuates DSS-induced colitis by affecting the intestinal microbiota

Background

The etiology and pathogenesis of inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), are generally believed to be related to immune dysfunction and intestinal microbiota disorder. However, the exact mechanism is not yet fully understood. The pathological changes associated with dextran sodium sulfate (DSS)-induced colitis are similar to those in human UC. As a subgroup of the innate immune system, group 3 innate lymphoid cells (ILC3s) are widely distributed in the lamina propria of the intestinal mucosa, and their function can be regulated by a variety of molecules. Musashi2 (MSI2) is a type of evolutionarily conserved RNA-binding protein that maintains the function of various tissue stem cells and is essential for postintestinal epithelial regeneration. The effect of MSI2 deficiency in ILC3s on IBD has not been reported. Thus, mice with conditional MSI2 knockout in ILC3s were used to construct a DSS-induced colitis model and explore its effects on the pathogenesis of IBD and the species, quantity and function of the intestinal microbiota.

Methods

Msi2^flox/flox mice (Msi2^fl/fl ) and Msi2^flox/floxRorc^Cre mice (Msi2^ΔRorc ) were induced by DSS to establish the IBD model. The severity of colitis was evaluated by five measurements: body weight percentage, disease activity index, colon shortening degree, histopathological score and routine blood examination. The species, quantity and function of the intestinal microbiota were characterized by high-throughput 16S rRNA gene sequencing of DNA extracted from fecal samples.

Results

MSI2 was knocked out in the ILC3s of Msi2^ΔRorc mice. The Msi2^ΔRorc mice exhibited reductions in body weight loss, the disease activity index, degree of colon shortening, tissue histopathological score and immune cells in the peripheral blood compared to those of Msi2^fl/fl mice after DSS administration. The 16S rRNA sequencing results showed that the diversity of the intestinal microbiota in DSS-treated Msi2^ΔRorc mice changed, with the abundance of Firmicutes increasing and that of Bacteroidetes decreasing. The linear discriminant analysis effect size (LEfSe) approach revealed that Lactobacillaceae could be the key bacteria in the Msi2^ΔRorc mouse during the improvement of colitis. Using PICRUST2 to predict the function of the intestinal microbiota, it was found that the functions of differential bacteria inferred by modeling were mainly enriched in infectious diseases, immune system and metabolic functions.

Conclusions

MSI2 deficiency in ILC3s attenuated DSS-induced colonic inflammation in mice and affected intestinal microbiota diversity, composition, and function, with Lactobacillaceae belonging to the phylum Firmicutes possibly representing the key bacteria. This finding could contribute to our understanding of the pathogenesis of IBD and provide new insights for its clinical diagnosis and treatment.

Structure design mechanisms and inflammatory disease applications of nanozymes

Nanozymes are artificial enzymes with high catalytic activity, low cost, and good biocompatibility, and have received ever-increasing attention in recent years. Various inorganic and organic nanoparticles have been found to exhibit enzyme-like activities and are used as nanozymes for diverse biomedical applications ranging from tumor imaging and therapeutics to detection. However, their further clinical applications are hindered by the potential toxicity and long-term retention of nanomaterials in vivo. Clarifying the catalytic mechanism of nanozymes and identifying the key factors responsible for their behavior can guide the design of nanozyme structure, enlighten the ways to improve their enzyme-like activities, and minimize the dosage of nanozymes, leading to reduced toxicity to the human body for a real biomedical application prospect. In particular, inflammation occurring in numerous diseases is closely related to reactive oxygen species, and the active oxygen scavenging ability of nanozymes potentially exerts excellent therapeutic effects on inflammatory diseases. In this review, we systematically summarize the structure-activity relationship of nanozymes, including regulation strategies for size and morphology, surface structure, and composition. Based on the structure-activity mechanisms, a series of chemically designed nanozymes developed to target various inflammatory diseases are briefly summarized.

Ultrathin Hafnium Disulfide Atomic Crystals with ROS-Scavenging and Colon-Targeting Capabilities for Inflammatory Bowel Disease Treatment

The exciting success of NBTXR3 in the clinic has triggered a tumult of activities in the design and development of hafnium-based nanoparticles. However, due to the concerns of nondegradation and limited functions, the biomedical applications of Hf-based nanoparticles mainly focus on tumors. Herein, tannic acid capped hafnium disulfide (HfS₂@TA) nanosheets, a 2D atomic crystal of hafnium-based materials prepared by liquid-phase exfoliation, were explored as high-performance anti-inflammatory nanoagents for the targeted therapy of inflammatory bowel disease (IBD). Benefiting from the transformation of the S^2-/S⁶⁺ valence state and huge specific surface area, the obtained HfS₂@TA nanosheets were not only capable of effectively eliminating reactive oxygen species/reactive nitrogen species and downregulating pro-inflammatory factors but also could be excreted via kidney and hepatointestinal systems. Unexpectedly, HfS₂@TA maintained excellent targeting capability to an inflamed colon even in the harsh digestive tract environment, mainly attributed to the electrostatic interactions between negatively charged tannic acid and positively charged inflamed epithelium. Encouragingly, upon oral or intravenous administration, HfS₂@TA quickly inhibited inflammation and repaired the intestinal mucosa barrier in both dextran sodium sulfate and 2,4,6-trinitrobenzenesulfonic acid induced IBD models. This work demonstrated that ultrathin HfS₂@TA atomic crystals with enhanced colon accumulation were promising for the targeted therapy of IBD.

Advances in Delivering Oxidative Modulators for Disease Therapy

Oxidation modulators regarding antioxidants and reactive oxygen species (ROS) inducers have been used for the treatment of many diseases. However, a systematic review that refers to delivery system for divergent modulation of oxidative level within the biomedical scope is lacking. To provide a comprehensive summarization and analysis, we review pilot designs for delivering the oxidative modulators and the main applications for inflammatory treatment and tumor therapy. On the one hand, the antioxidants based delivery system can be employed to downregulate ROS levels at inflammatory sites to treat inflammatory diseases (e.g., skin repair, bone-related diseases, organ dysfunction, and neurodegenerative diseases). On the other hand, the ROS inducers based delivery system can be employed to upregulate ROS levels at the tumor site to kill tumor cells (e.g., disrupt the endogenous oxidative balance and induce lethal levels of ROS). Besides the current designs of delivery systems for oxidative modulators and the main application cases, prospects for future research are also provided to identify intelligent strategies and inspire new concepts for delivering oxidative modulators.

Antioxidative myricetin-enriched nanoparticles towards acute liver injury

Acute liver injury (ALI) could severely destroy the liver function and cause inevitable damage to human health. Studies have demonstrated that excessive reactive oxygen species (ROS) and accompanying inflammatory factors play vital roles in the ALI disease. Herein, we fabricated a kind of nature-inspired myricetin-enriched nanomaterial via Michael addition and Schiff base reaction, which possessed uniform morphology, tunable component ratios, great stabilities, promising free radical scavenging abilities, biocompatibility and protective effects towards cells under oxidative stress. Additionally, the therapeutic effects were demonstrated using an ALI model by down-regulating ROS and inflammatory levels and restoring the liver function. This study could provide a strategy to construct robust and antioxidative nanomaterials using naturally occurring molecules against intractable diseases.

Intestinal Claudin-7 deficiency impacts the intestinal microbiota in mice with colitis

BACKGROUND

Intestinal epithelial cells form a physical barrier that protects the intestine against the intestinal microbiota through tight junctions (TJs) and adhesive junctions, while barrier disruption may lead to inflammatory bowel disease (IBD). Claudin-7 (Cldn7) has been implicated in this protection as an important member of TJs. Here, we experimentally study the effect of Cldn7 deletion on intestinal microbiota in colitis.

METHODS

Colitis model was established based on inducible intestinal conditional Cldn7 gene knockout mice (Cldn7fl/fl; villin-CreERT2), by feeding with dextran sodium sulfate (DSS). AB-PAS staining and immunohistochemical staining of Muc2 mucin were used to detect the effect of Cldn7 deficiency on the mucus layer of mice with colitis, and fluorescence in situ hybridization was used to detect how Cldn7 promotes spatial separation of the gut microbiota from the host. The microbiota population was characterized by high-throughput 16S rRNA gene sequencing of DNA extracted from fecal samples.

RESULTS

Compared with the controls, Cldn7 knockout increased susceptibility to colitis, including greater degree of weight loss, colon shortening, and a significantly higher disease activity index score. DSS-treated Cldn7 knockout mice promoted the migration of bacteria to the intestinal epithelium to some extent by damaging the intestinal mucus layer. Sequencing of 16S rRNA showed that DSS-treated Cldn7 knockout mice reduced the gut microbiota diversity and had greater relative abundance of Escherichia coli. LEfSe analysis indicated that Escherichia coli may be the key bacteria in Cldn7 knockout mice during DSS-induced colitis. Furthermore, the Tax4Fun analysis predicted that DSS-treated Cldn7 knockout mice enriched for microbiota impacting infectious diseases, immune system and metabolic functions.

CONCLUSIONS

Our data suggests an association between intestinal Cldn7 knockout and microbiota dysbiosis during inflammatory events.

Oxidative Stress and Antioxidant Nanotherapeutic Approaches for Inflammatory Bowel Disease

Oxidative stress, caused by the accumulation of reactive species, is associated with the initiation and progress of inflammatory bowel disease (IBD). The investigation of antioxidants to target overexpressed reactive species and modulate oxidant stress pathways becomes an important therapeutic option. Nowadays, antioxidative nanotechnology has emerged as a novel strategy. The nanocarriers have shown many advantages in comparison with conventional antioxidants, owing to their on-site accumulation, stability of antioxidants, and most importantly, intrinsic multiple reactive species scavenging or catalyzing properties. This review concludes an up-to-date summary of IBD nanomedicines according to the classification of the delivered antioxidants. Moreover, the concerns and future perspectives in this study field are also discussed.