A superoxide dismutase/catalase mimetic nanomedicine for targeted therapy of inflammatory bowel disease

ROS-responsive thioketal nanoparticles delivering system for targeted ulcerative colitis therapy with potent HDAC6 inhibitor, tubastatin A

Ulcerative colitis (UC) is a common gastrointestinal problem characterized by the mucosal injury primarily affecting the large intestine. Currently available therapies are not satisfactory as evidenced by high relapse rate and adverse effects. In this study we aimed to develop an effective drug delivery system using reactive oxygen species (ROS)-responsive thioketal nanoparticles (TKNP), to deliver tubastatin A, a potent HDAC6 inhibitor, to the inflamed colon in mice with ulcerative colitis (UC). TKNPs were synthesized by step-growth polymerization from an acetal exchange reaction while TUBA-TKNP was prepared using the single emulsion solvent evaporation technique. Our developed nanoparticle showed release of tubastatin A only in presence of ROS which is found to be highly present at the site of inflamed colon. Oral administration of TUBA-TKNP resulted in the higher accumulation of tubastatin A at the inflamed colon site and decreased the inflammation as evidenced by reduced infiltration of immune cells and decreased level of pro-inflammatory cytokines in TUBA-TKNP treated mice. In summary, our results show the successful localization of tubastatin A at the site of colon inflammation through TUBA-TKNP delivery, as well as resolution of clinical features of UC in mice.

Redox-sensitive hydrogel based on hyaluronic acid with selenocystamine cross-linking for the delivery of Limosilactobacillus reuteri in a DSS-induced colitis mouse model

Disrupted gut microbiota homeostasis is an important cause of inflammatory colitis. Studies have shown that effective supplementation with probiotics can maintain microbial homeostasis and alleviate colitis. Here, to increase the viability of probiotics in the harsh gastrointestinal environments and enable targeted delivery, a redox-sensitive selenium hyaluronic acid (HA-Se) hydrogel encapsulating probiotics was developed. HA was modified with selenocystamine dihydrochloride and crosslinked by an amide reaction to generate a redox-sensitive hydrogel with stable mechanical properties, a low hemolysis rate and satisfactory biocompatibility. The HA-Se hydrogel exhibited suitable sensitivity to 10 mM GSH or 100 μM H2O2. The encapsulation of Limosilactobacillus reuteri (LR) in the HA-Se hydrogel (HA-Se-LR) significantly increased the survival rate of the probiotics in simulated gastric and intestinal fluid. HA-Se-LR administration increased the survival rate of mice with dextran sulfate sodium (DSS)-induced colitis, significantly alleviated oxidative stress and inflammation, and increased the effect of LR on microbiota α diversity. These results indicate that the HA-Se hydrogel constructed in this study can be used as a delivery platform to treat colitis, expanding the targeted applications of the natural polymer HA in disease treatment and the administration of probiotics as drugs to alleviate disease symptoms.

Ganoderic Acid A Mitigates Inflammatory Bowel Disease through Modulation of AhR Activity by Microbial Tryptophan Metabolism

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a complex gastrointestinal condition influenced by genetic, microbial, and environmental factors, among which the gut microbiota plays a crucial role and has emerged as a potential therapeutic target. Ganoderic acid A (GAA), which is a lanostane triterpenoid compound derived from edible mushroom Ganoderma lucidum, has demonstrated the ability to modulate gut dysbiosis. Thus, we investigated the impact of GAA on IBD using a dextran sodium sulfate (DSS)-induced colitis mouse model. GAA effectively prevented colitis, preserved epithelial and mucus layer integrity, and modulated the gut microbiota. In addition, GAA promoted tryptophan metabolism, especially 3-IAld generation, activated the aryl hydrocarbon receptor (AhR), and induced IL-22 production. Fecal microbiota transplantation validated the mediating role of the gut microbiota in the IBD protection conferred by GAA. Our study suggests that GAA holds potential as a nutritional intervention for ameliorating IBD by influencing the gut microbiota, thereby regulating tryptophan metabolism, enhancing AhR activity, and ultimately improving gut barrier function.

Macrocycle-Based Supramolecular Drug Delivery Systems: A Concise Review

Efficient delivery of therapeutic agents to the lesion site or specific cells is an important way to achieve "toxicity reduction and efficacy enhancement". Macrocycles have always provided many novel ideas for drug or gene loading and delivery processes. Specifically, macrocycles represented by crown ethers, cyclodextrins, cucurbit[n]urils, calix[n]arenes, and pillar[n]arenes have unique properties, which are different cavity structures, good biocompatibility, and good stability. Benefited from these diverse properties, a variety of supramolecular drug delivery systems can be designed and constructed to effectively improve the physical and chemical properties of guest molecules as needed. This review provides an outlook on the current application status and main limitations of macrocycles in supramolecular drug delivery systems.

Residue-Free Orally Administered Drug Carrier Based on a Porous Aromatic Framework for Efficient Multisite Treatment

Nowadays, oral medications are the primary method of treating disease due to their convenience, low cost, and safety, without the need for complex medical procedures. To maximize treatment effectiveness, almost all oral medications utilize drug carriers, such as capsules, liposomes, and sugar coatings. However, these carriers rely on dissolution or fragmentation to achieve drug release, which leads to drugs and carriers coabsorption in the body, causing unnecessary adverse drug reactions, such as nausea, vomiting, abdominal pain, and even death caused by allergy. Therefore, the ideal oral drug carrier should avoid degradation and absorption and be totally excreted after drug release at the desired location. Herein, a gastrointestinally stable oral drug carrier based on porous aromatic framework-1 (PAF-1) is constructed, and it is modified with famotidine (a well-known gastric drug) and mesalazine (a well-known ulcerative colitis drug) to verify the excellent potential of PAF-1. The results demonstrate that PAF-1 can accurately release famotidine in stomach, mesalazine in the intestine, and finally be completely excreted from the body without any residue after 12 h. The use of PAF materials for the construction of oral drug carriers with no residue in the gastrointestinal tract provides a new approach for efficient disease treatment.

Postbiotics in inflammatory bowel disease: efficacy, mechanism, and therapeutic implications

Inflammatory bowel disease (IBD) is one of the most challenging diseases in the 21st century, and more than 10 million people around the world suffer from IBD. Because of the limitations and adverse effects associated with conventional IBD therapies, there has been increased scientific interest in microbial-derived biomolecules, known as postbiotics. Postbiotics are defined as the preparation of inanimate microorganisms and/or their components that confer a health benefit on the host, comprising inactivated microbial cells, cell fractions, metabolites, etc. Postbiotics have shown potential in enhancing IBD treatment by reducing inflammation, modulating the immune system, stabilizing intestinal flora and maintaining the integrity of intestinal barriers. Consequently, they are considered promising adjunctive therapies for IBD. Recent studies indicate that postbiotics offer distinctive advantages, including spanning clinical (safe origin), technological (easy for storage and transportation) and economic (reduced production costs) dimensions, rendering them suitable for widespread applications in functional food/pharmaceutical. This review offers a comprehensive overview of the definition, classification and applications of postbiotics, with an emphasis on their biological activity in both the prevention and treatment of IBD. © 2024 Society of Chemical Industry.

Nanoparticle-Based Drug Delivery Systems for Inflammatory Bowel Disease Treatment

Inflammatory bowel disease (IBD) is a chronic, non-specific inflammatory condition characterized by recurring inflammation of the intestinal mucosa. However, the existing IBD treatments are ineffective and have serious side effects. The etiology of IBD is multifactorial and encompasses immune, genetic, environmental, dietary, and microbial factors. The nanoparticles (NPs) developed based on specific targeting methodologies exhibit great potential as nanotechnology advances. Nanoparticles are defined as particles between 1 and 100 nm in size. Depending on their size and surface functionality, NPs exhibit different properties. A variety of nanoparticle types have been employed as drug carriers for the treatment of inflammatory bowel disease (IBD), with encouraging outcomes observed in experimental models. They increase the bioavailability of drugs and enable targeted drug delivery, promoting localized treatment and thus enhancing efficacy. Nevertheless, numerous challenges persist in the translation from nanomedicine to clinical application, including enhanced formulations and preparation techniques, enhanced drug safety profiles, and so forth. In the future, it will be necessary for scientists and clinicians to collaborate in order to study disease mechanisms, develop new drug delivery strategies, and screen new nanomedicines. Nevertheless, numerous challenges persist in the translation from nanomedicine to clinical application, including enhanced formulations and preparation techniques, enhanced drug safety profiles, and so forth. In the future, it will be necessary for scientists and clinicians to collaborate in order to study disease mechanisms, develop new drug delivery strategies, and screen new nanomedicines.

Cu,Zn,I-Doped Carbon Dots with Boosted Triple Antioxidant Nanozyme Activity for Treatment of DSS-Induced Colitis

Nanozyme-mediated antioxidative therapy is a promising star for treating a myriad of important diseases through eliminating excessive reactive oxygen species (ROS) such as O2·- and H2O2, a critical mechanism for inflammatory bowel disease (IBD). This work provides a high biocompatibility iodine-copper-zinc covalent doped carbon dots (Cu,Zn,I-CDs) with the catalase (CAT)-, superoxide dismutase (SOD)- and glutathione peroxidase (GPx)-like catalytic activities for treating ulcerative colitis (UC) by scavenging overproduced ROS. We found that I dopant aids in counteracting the positive charge at Cu,Zn dopants brought on by low pH, enabling Cu,Zn,I-CDs to process strong triple antioxidant nanozyme activities rather than Cu,Zn-CDs. Vitro experiments displayed that the Cu,Zn,I-CDs could scavenge the excessive ROS to protect cellular against oxidative stress and reduce the expression of proinflammatory cytokines, such as TNF-α, IL-1β, and IL-6. In sodium dextran sulfate (DSS)-induced colitis mice models, Cu,Zn,I-CDs with excellent biocompatibility could effectively relieve the inflammation of the colon, containing the reduction of the colon length, the damaged epithelium, the infiltration of inflammatory cells, and upregulation of antioxidant genes. Therefore, the therapy of Cu,Zn,I-CD antioxidant nanozymes is an effective approach and provides a novel strategy for UC treatment.

ROS-responsive nano-medicine for navigating autophagy to enhance targeted therapy of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic gastrointestinal disorder characterized by immune dysregulation and intestinal inflammation. Rapamycin (Ra), an mTORC1 pathway inhibitor, has shown promise for autophagy induction in IBD therapy but is associated with off-target effects and toxicity. To address these issues, we developed an oral liposome responsive to reactive oxygen species (ROS) using lipids and amphiphilic materials. We combined ketone thiol (TK) for ROS responsive and hyaluronic acid (HA) with high affinity for CD44 receptors to prepare rapamycin-loaded nanoparticle (Ra@TH). Owing to its ROS responsive characteristic, Ra@TH can achieve inflammatory colonic targeting. Additionally, Ra@TH can induce autophagy by inhibiting the mTORC1 pathway, leading to the clearance of damaged organelles, pathogenic microorganisms and oxidative stress products. Simultaneously, it also collaboratively inhibits the NF-κB pathway suppressed by the removal of ROS resulting from TK cleavage, thereby mediating the expression of inflammatory factors. Furthermore, Ra@TH enhances the expression of typical tight junction proteins, synergistically restoring intestinal barrier function. Our research not only expands the understanding of autophagy in IBD treatment but also introduces a promising therapeutic approach for IBD patients.

Enhancing stem cell therapy efficacy with functional lignin modified cerium-iron nanozyme through magnetic resonance imaging tracking and apoptosis protection in inflammatory environment

Stem cell transplantation provides a promising approach for addressing inflammation and functional disorders. Nonetheless, the viability of these transplanted cells diminishes significantly within pathological environments, limiting their therapeutic potential. Moreover, the non-invasive tracking of these cells in vivo remains a considerable challenge, hampering the assessment of their therapeutic efficacy. Transition-metal oxide nanocrystals, known for their unique "enzyme-like" catalytic property and imaging capability, provide a new avenue for clinical application. In this study, the lignin as a biocompatible macromolecule was modified with poly (ethylene glycol) through chain-transfer polymerization, and then it was utilized to incorporate superparamagnetic iron oxide and cerium oxide nanocrystals creating a functional nanozyme. The iron oxide nanocrystals self-assembled into the hydrophobic core of nano system, while the in-situ mineralization of cerium oxide particles was carried out with the assistance of peripheral phenolic hydroxyl groups. The product, cerium‑iron core-shell nanozyme, enabled effective stem cells labeling through endocytosis and exhibited catalase and superoxide dismutase activities within the cells. As a result, it could scavenge highly destructive hydroxyl radicals and peroxyl radicals, shielding stem cells from apoptosis in inflammatory environment and maintaining their differentiation ability. Additionally, when these functionalized stem cells were administered to mice with acute inflammation, not only did they alleviate disease symptoms, but they also allowed for the visualization using T2-weighted magnetic resonance imaging. This innovative therapeutic approach provides a new strategy for combatting diseases.

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.

Superoxide dismutase nanozymes: current status and future perspectives on brain disease treatment and diagnosis

Superoxide dismutase (SOD) is an important metalloenzyme that catalyzes the dismutation of superoxide radicals (O2˙-) into hydrogen peroxide (H2O2) and oxygen (O2). However, the clinical application of SOD is severely limited due to its structural instability and high cost. Compared with natural enzymes, nanomaterials with enzyme-like activity, nanoenzymes, are more stable, economical and easy to modify and their activity can be adjusted. Certain nanozymes that exhibit SOD-like activity have been created and shown to help prevent illnesses brought about by oxidative stress. These SOD-like nanozymes offer an important solution to the problems associated with the clinical application of SOD. In this review, we briefly introduce neurodegenerative diseases, present the research progress of SOD-like nanoenzymes in the diagnosis and treatment of brain diseases, review their mechanism of action in the treatment and diagnosis of brain diseases, and discuss the shortcomings of the current research with a view to providing a reference for future research. We expect more highly active SOD-like nanoenzymes to be developed with a wide range of applications in the diagnosis and treatment of brain diseases.

Sex-specific colonic mitochondrial dysfunction in the indomethacin-induced rat model of inflammatory bowel disease

Introduction: Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract and encompasses Crohn's Disease and Ulcerative Colitis. Women appear to have more severe and recurring symptoms of IBD compared to men, most likely due to hormonal fluctuations. Studies have shown that mitochondrial dysfunction plays a role in the development of inflammation and there is evidence of colon mitochondrial alterations in IBD models and patients. In this study we have identified the presence of sex-specific colon mitochondrial dysfunction in a rat model of IBD. Methods: Eight-week-old male and female rats were treated with indomethacin to induce IBD and mitoTEMPO was administered daily either after or before induction of IBD and until euthanasia. Colons were collected for histology and mitochondrial experiments. Intact mitochondrial respiration, reactive oxygen species (mtROS), the activities of the individual electron transport complexes and the activities of the antioxidant enzymes were measured to assess mitochondrial function. Results: IBD male rats showed a decrease in citrate synthase activity, cardiolipin levels, catalase activity and an increase in mtROS production. IBD females show a decrease in intact colon mitochondrial respiration, colon mitochondria respiratory control ratio (RCR), complex I activity, complex IV activity, and an increase in mtROS. Interestingly, control females showed a significantly higher rate of complex I and II-driven intact mitochondrial respiration, MCFA oxidation, complex II activity, complex III activity, and complex IV activity compared to control males. The use of a mitochondrial-targeted therapy, mitoTEMPO, improved the disease and colon mitochondrial function in female IBD rats. However, in the males there was no observed improvement, likely due to the decrease in catalase activity. Conclusion: Our study provides a better understanding of the role mitochondria in the development of IBD and highlights sex differences in colon mitochondrial function. It also opens an avenue for the development of strategies to re-establish normal mitochondrial function that could provide more options for preventive and therapeutic interventions for IBD.

Antioxidant nanozymes as next-generation therapeutics to free radical-mediated inflammatory diseases: A comprehensive review

Recent developments in exploring the biological enzyme mimicking properties in nanozymes have opened a separate avenue, which provides a suitable alternative to the natural antioxidants and enzymes. Due to high and tunable catalytic activity, low cost of synthesis, easy surface modification, and good biocompatibility, nanozymes have garnered significant research interest globally. Several inorganic nanomaterials have been investigated to exhibit catalytic activities of some of the key natural enzymes, including superoxide dismutase (SOD), catalase, glutathione peroxidase, peroxidase, and oxidase, etc. These nanozymes are used for diverse biomedical applications including therapeutics, imaging, and biosensing in various cells/tissues and animal models. In particular, inflammation-related diseases are closely associated with reactive oxygen and reactive nitrogen species, and therefore effective antioxidants could be excellent therapeutics due to their free radical scavenging ability. Although biological enzymes and other artificial antioxidants could perform well in scavenging the reactive oxygen and nitrogen species, however, suffer from several drawbacks such as the requirement of strict physiological conditions for enzymatic activity, limited stability in the environment beyond their optimum pH and temperature, and high cost of synthesis, purification, and storage make then unattractive for broad-spectrum applications. Therefore, this review systematically and comprehensively presents the free radical-mediated evolution of various inflammatory diseases (inflammatory bowel disease, mammary gland fibrosis, and inflammation, acute injury of the liver and kidney, mammary fibrosis, and cerebral ischemic stroke reperfusion) and their mitigation by various antioxidant nanozymes in the biological system. The mechanism of free radical scavenging by antioxidant nanozymes under in vitro and in vivo experimental models and catalytic efficiency comparison with corresponding natural enzymes has also been presented.

Gelatin-decorated Graphene oxide: A nanocarrier for delivering pH-responsive drug for improving therapeutic efficacy against atherosclerotic plaque

The progressive inflammatory disease atherosclerosis promotes myocardial infarction, stroke, and heart attack. Anti-inflammatory drugs treat severe atherosclerosis. They are inadequate bioavailability and cause adverse effects at higher doses. A new nanomaterial coupled pH-apperceptive drug delivery system for atherosclerotic plaque is outlined here. We have synthesized a Graphene Oxide-Gelatin-Atorvastatin (GO-Gel-ATR) nanodrug characterized by spectroscopic and imaging techniques. The encapsulation efficiency of GO-Gel-ATR (79.2%) in the loading process is observed to be better than GO-ATR (66.8%). The internal milieu of the plaque cells has a pH of 6.8. The GO-Gel-ATR displays sustained and cumulative release profile at pH 6.8 compared to ATR and GO-ATR. Our proposed nanocomposite demonstrated high cytocompatibility up to 100μg/mL in foam cells induced by Oxidized-Low Density Lipoprotein (Ox-LDL) and Lipopolysaccharides (LPS) compared to normal macrophages for 24 and 48 h. The uptake efficacy of the nanodrugs is shown to be enhanced in foam cells compared to normal macrophage. Oil red O staining of foam cells with and without drugs confirmed therapeutic efficacy. Foam cells treated with nanocomposite had more lipids efflux than ATR. The finding of the in-vitro study reveals that the GO-Gel-ATR nanocomposite carriers have the potential to deliver anti-atherosclerotic drugs effectively and inhibit atherosclerotic plaque progression.

Emerging drug delivery systems with traditional routes - A roadmap to chronic inflammatory diseases

Inflammation is prevalent and inevitable in daily life but can generally be accommodated by the immune systems. However, incapable self-healing and persistent inflammation can progress to chronic inflammation, leading to prevalent or fatal chronic diseases. This review comprehensively covers the topic of emerging drug delivery systems (DDSs) for the treatment of chronic inflammatory diseases (CIDs). First, we introduce the basic biology of the chronic inflammatory process and provide an overview of the main CIDs of the major organs. Next, up-to-date information on various DDSs and the associated strategies for ensuring targeted delivery and stimuli-responsiveness applied to CIDs are discussed extensively. The implementation of traditional routes of drug administration to maximize their therapeutic effects against CIDs is then summarized. Finally, perspectives on future DDSs against CIDs are presented.

Stimuli-responsive nanoparticles delivered by a nasal-brain pathway alleviate depression-like behavior through extensively scavenging ROS

Depression is one of the most common mental diseases, which seriously affects patients' physical and mental health. Emerging evidence has indicated that oxidative stress (OS) is a major cause of neurodegeneration involved in the pathogenesis of depression. Consequently, targeted reactive oxygen species (ROS) elimination is regarded as a promising strategy for efficient depression therapy. In addition, insufficient brain drug delivery is the main obstacle to depression therapy owing to the presence of the blood-brain barrier (BBB). To achieve the goals of bypassing the BBB and promoting antioxidant therapy for depression, a broad-spectrum ROS scavenging NPs was rationally designed through a nasal-brain pathway developed for combined ROS scavenging and brain drug delivery. A hexa-arginine (R6) modified ROS-responsive dextran (DEX) derivate was synthesized for antidepressant olanzapine (Olz) and H2 donor amino borane (AB) loading to prepare Olz/RDPA nanoparticles (NPs). Subsequently, the NPs were dispersed into a thermoresponsive hydrogel system based on poloxamer. In vitro and in vivo results demonstrated that Olz/RDPA in situ thermoresponsive hydrogel system could effectively deliver NPs to the brain via the nasal-brain pathway and alleviate depression-like behaviors through combined ROS depletion and inhibition of 5-HT dysfunction of the oxidative stress-induced. The proposed ROS-scavenging nanotherapeutic would open a new window for depression treatment. STATEMENT OF SIGNIFICANCE: ROS is an innovative therapeutic target involving the pathology of depression whereas targeted delivery of ROS scavenging has not been achieved yet. In the current study, ROS-responsive nanoparticles (Olz/RDPA NPs) were prepared and dispersed in a thermosensitive hydrogel for delivery through the nasal-brain pathway for the treatment of depression. Sufficient ROS depletion and improvement of delivery capacity by the nasal-brain pathway effectively could reverse oxidative stress and alleviate depressive-like behavior. Collectively, these nanoparticles may represent a promising strategy for the treatment of depression.

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.

Armored probiotics for oral delivery

As a kind of intestinal flora regulator, probiotics show great potential in the treatment of many diseases. However, orally delivered probiotics are often vulnerable to unfriendly gastrointestinal environments, resulting in a low survival rate and decreased therapeutic efficacy. Decorating or encapsulating probiotics with functional biomaterials has become a facile yet useful strategy, and probiotics can be given different functions by wearing different armors. This review systematically discusses the challenges faced by oral probiotics and the research progress of armored probiotics delivery systems. We focus on how various functional armors help probiotics overcome different obstacles and achieve efficient delivery. We also introduce the applications of armor probiotics in disease treatment and analyze the future trends of developing advanced probiotics-based therapies.

A Biomimetic Nanoplatform with Improved Inflammatory Targeting Behavior for ROS Scavenging-Based Treatment of Ulcerative Colitis

Ulcerative colitis (UC), a refractory disease, has become a global problem. Herein, a biomimetic nanoplatform (AU-LIP-CM) comprising Au cluster enzymes (AU)-loaded liposomes (AU-LIP) camouflaged with the fusion membrane (CM) consisting of neutrophil (NC) and red blood cell (RBC) membrane is designed for the treatment of UC. Briefly, revealed by second near-infrared (NIR-II) imaging through collection of fluorescence emitting >1200 nm from AU, the improved inflammatory targeting behavior contributed by CM cloaking, which inherits abilities of inflammatory targeting and immune escape from NC and RBC, respectively, promotes specific accumulation of AU within inflammatory intestines with up to ≈11.5 times higher than that of bare AU. Afterward, AU possessing superoxide dismutase- and catalase-like activities realizes high-efficiency scavenging of reactive oxygen species (ROS), leading to repair of intestinal barriers, regulation of the immune system, and modulation of gut microbiota, which surpass first-line UC drug. In addition, study of underlying therapeutic mechanism demonstrated that the treatment with AU-LIP-CM can alter the gene signature associated with response to ROS for UC mice to a profile similar to that of healthy mice, deciphering related signal pathways. The strategy developed here provides insights of learning from properties of natural bio-substances to empower biomimetic nanoplatform to confront diseases.

An oral polyphenol host-guest nanoparticle for targeted therapy of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a global public health challenge that affects millions of people. Current medical treatments for IBD are not fully effective and may cause undesirable side effects on patients. Thus, there is an urgent need for safe, simple, and efficacious strategies to treat IBD in clinical settings. Here, we develop an oral polyphenol nanoparticle (PDT) by assembling dexamethasone sodium phosphate (DSP)-loaded poly-β-cyclodextrin with tannic acid via host-guest interactions for treating IBD. This one-step assembly process is rapid (within 10 s), reproducible, and free of harmful chemical agents, which can facilitate its clinical translation. PDT is negatively charged due to the three components, which enable it to specifically target the positively charged inflamed colonic mucosa through electrostatic attraction, thus localizing the drug at the inflamed site to reduce systemic exposure and side effects. Furthermore, PDT exhibits a strong reactive oxygen species (ROS)-scavenging ability derived from the tannic acid component, which can alleviate ROS-mediated inflammatory responses and ameliorate IBD symptoms. Compared with free DSP, PDT demonstrates sustained DSP release behavior in vitro and in vivo, as well as enhanced therapeutic efficacy in a colitis mouse model. These results suggest that PDT might be a potential therapeutic agent for the treatment of IBD. Moreover, this facile polyphenol host-guest assembly strategy may provide a promising drug-delivery platform for treating various diseases STATEMENT OF SIGNIFICANCE: To develop safe and effective treatments for inflammatory bowel disease (IBD), we have designed an oral polyphenol nanoparticle (PDT) using the host-guest assembly of dexamethasone sodium phosphate (DSP)-loaded poly-β-cyclodextrin with tannic acid. Through in vitro and in vivo experiments, PDT has demonstrated remarkable inflammation-targeting, ROS-scavenging, and anti-inflammatory properties, along with sustained release of DSP. Moreover, in an IBD mouse model, PDT has shown significantly improved therapeutic efficacy compared to free DSP. The host-guest assembly strategy employed for PDT is noteworthy for its rapidity, reproducibility, and safety due to the absence of harmful chemicals, holding great promise for designing a diverse range of nanomedicines customized for treating various diseases.

Stimulation-responsive mucoadhesive probiotics for inflammatory bowel disease treatment by scavenging reactive oxygen species and regulating gut microbiota

Inflammatory bowel disease (IBD) is characterized by the high level of reactive oxygen species (ROS) and highly dysfunctional intestinal flora. Here, a stimulation-responsive mucoadhesive probiotic Lac@HDP was rationally constructed for achieving specific adhesion of colitis site and depleting high level of ROS in inflammatory site. Briefly, Lac is Lactobacillus acidophilus, HDP is obtained by hyaluronic acid grafted with dopamine protected by phenylboric acid. Specifically, by consuming a large amount of ROS, phenyl borate group of Lac@HDP is oxidized and fractured, thus exposing the catechol hydroxyl group and obtaining strong mucosal adhesion ability, thereby significantly prolong the retention time of Lac in the inflammatory site. In the murine model of acute and chronic colitis, the stimulation-responsive mucoadhesive probiotics were significantly more effective in alleviating colitis symptoms than antioxidants and probiotics alone. In addition, the abundance and diversity of intestinal flora were increased after treatment with Lac@HDP, which was helpful to alleviate IBD. Importantly, the stimulation-responsive mucoadhesive probiotics have good biological safety in vivo, which provides the prospect of clinical application in the future.

Incidental nanoparticles in black tea alleviate DSS-induced ulcerative colitis in BALB/c mice

As the dominant herbal drink consumed worldwide, black tea exhibits various health promoting benefits including amelioration of inflammatory bowel diseases. Despite extensive studies on the tea's components, little is known about the bioactivities of nanoparticles (NPs) which were incidentally assembled in the tea infusion and represent the major components. This study investigated the alleviative effects of black tea infusion, the isolated black tea NPs, and a mixture of caffeine, epigallocatechin-3-gallate, gallic acid and epicatechin gallate on dextran sodium sulfate (DSS)-induced ulcerative colitis. The results showed that both the black tea infusion and the NPs significantly alleviated colitis, suppressed the mRNA levels of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, and suppressed the DSS-induced loss of cell-cell junction proteins (e.g., E-cadherin, ZO-1, and claudin-1) and increase of p-STAT3. The mixture of four tea components, which is the analogue of bioactive payloads carried by the NPs, was much less effective than the tea infusion and NPs. It shows that the NPs elevate the efficiency of polyphenols and caffeine in black tea in restoring the intercellular connection in the intestine, inhibiting mucosal inflammation, and alleviating ulcerative colitis. This work may inspire the development of tea-based therapeutics for treating inflammatory bowel diseases and have wide influences on value-added processing, quality evaluation, functionalization, and innovation of tea and other plant-based beverages.

Polydopamine Modified Ceria Nanorods Alleviate Inflammation in Colitis by Scavenging ROS and Regulating Macrophage M2 Polarization

Background

Inflammatory bowel disease (IBD) is closely related to higher intracellular oxidative stress. Therefore, developing a novel method to scavenge the harmful reactive oxygen species (ROS) and alleviate colon inflammation to treat IBD is a promising strategy.

Methods

CeO2@PDA-PEG (CeO2@PP) were synthesized by modifying ceria (CeO2) nanorods with polydopamine (PDA) and polyethylene glycol (PEG). The ROS scavenging ability of CeO2@PP was detected by using flow cytometry and confocal laser scanning microscope (CLSM). The anti-inflammatory ability of CeO2@PP was determined in vitro by treating lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The biocompatibility of CeO2@PP was evaluated in vivo and in vitro. Moreover, the therapeutic effects of CeO2@PP in vivo were estimated in a dextran sulfate sodium salt (DSS)-induced colitis mouse model.

Results

Physicochemical property results demonstrated that PDA and PEG modification endowed CeO2 nanorods with excellent dispersibility and colloidal stability. CeO2@PP maintained superior enzyme-like activity, including superoxide dismutase (SOD) and catalase (CAT), indicating antioxidant ability. Moreover, in vitro results showed that CeO2@PP with PDA promotes LPS-induced RAW 264.7 macrophages into M2-type polarization. In addition, in vitro and in vivo results showed that CeO2@PP have great biocompatibility and biosafety. Animal experiments have shown that CeO2@PP have excellent anti-inflammatory effects against DSS-induced colitis and effectively alleviated intestinal mucosal injury.

Conclusion

The nanoplatform CeO2@PP possessed excellent antioxidant and anti-inflammatory properties for scavenging ROS and modulating macrophage polarization, which is beneficial for efficient colitis therapy.

Gastrointestinal Microenvironment Responsive Nanoencapsulation of Probiotics and Drugs for Synergistic Therapy of Intestinal Diseases

The gut microbiota are prominent in preserving intestinal environmental homeostasis and managing human health, and their dysbiosis has been directly related to many kinds of intestinal diseases. Probiotics-based therapy appears as a promising approach for the treatment of gut microbiota dysbiosis, while it always suffers from limited bioavailability and therapeutic effect after oral administration. Herein, we presented a facile and safe strategy to treat colitis by nanoencapsulation of probiotics and an anti-inflammatory agent, 5-aminosalicylic acid (5-ASA), within the gastrointestinal microenvironment responsive alginate polysaccharide. Because of acid resistance, the alginate-based coating protected probiotics from the harsh gastric condition. The coating could be disintegrated to release probiotics and 5-ASA upon arriving in the intestinal tract, where the pH is normally higher than 5. In the dextran sulfate sodium-induced colitis mouse model, probiotics recovered their bioactivities and acted together with anti-inflammatory 5-ASA to alleviate colitis by upregulating microbiota richness and diversity, reducing expression of proinflammatory cytokines, and restoring intestinal barriers. This work demonstrated the synergistic therapy of intestinal diseases based on alginate-encapsulated probiotics and a clinical drug, which provided an extensive method to improve the therapeutic effect of oral microecologics.

Hyaluronic acid modified oral drug delivery system with mucoadhesiveness and macrophage-targeting for colitis treatment

Based on the biocompatibility and macrophage targeting of natural polysaccharides, combined with the physiological and pathological characteristics of the gastrointestinal tract and colonic mucosa of ulcerative colitis (UC), we prepare dexamethasone (Dex)-loaded oral colon-targeted nano-in-micro drug delivery systems coated with multilayers of chitosan (CS), hyaluronic acid (HA), and finally Eudragit S100 (ECHCD MPs) using a layer-by-layer coating technique for UC treatment through regulating the M1/M2 polarization of intestinal macrophages. HA/CS/Dex nanoparticles (HCD NPs) are ingested by macrophages via CD44 receptor-mediated endocytosis to regulate M1-to-M2 macrophage polarization and exert anti-inflammatory effects. Moreover, ECHCD MPs show better colon-targeting properties than Dex-loaded chitosan nanoparticles (CD NPs) and HCD NPs which is demonstrated by stronger mucoadhesion to inflamed colon tissues. After oral administration, ECHCD MPs exert significant anti-UC effects. Therefore, ECHCD MPs are proven to be as promising oral colon-targeting drug delivery systems for Dex and have potential application in UC treatment.

Calcium Tungstate Microgel Enhances the Delivery and Colonization of Probiotics during Colitis via Intestinal Ecological Niche Occupancy

The effective delivery and colonization of probiotics are recommended for therapeutic interventions during colitis, the efficacy of which is hampered by abnormally colonized Enterobacteriaceae at pathological sites. To improve the delivery and colonization of probiotics, a calcium tungstate microgel (CTM)-based oral probiotic delivery system is proposed herein. CTM can selectively disrupt the ecological niche occupied by abnormally expanded Enterobacteriaceae during colitis to facilitate probiotic colonization. In addition, the calcium-binding protein, calprotectin, which is highly expressed in colitis, efficiently extracts calcium from CTM and releases tungsten to inhibit Enterobacteriaceae by displacing molybdenum in the molybdenum enzyme, without affecting the delivered probiotics. Moreover, CTM demonstrated resistance to the harsh environment of the gastrointestinal (GI) tract and to intestinal adhesion. The synergistic reduction of Enterobacteriaceae by 45 times and the increase in probiotic colonization by 25 times, therefore, result in a remarkable treatment for colitis, including restoration of colonic length, effective downregulation of the inflammatory response, restoration of the damaged mucosal barrier, and restoration of gut microbiome homeostasis.

Biomimetic Molybdenum Sulfide-Catalyzed Tumor Ferroptosis and Bioimaging

The chemical generation of singlet oxygen (¹ O₂ ) by the MoO₄ ^2- -catalyzed disproportionation of hydrogen peroxide (H₂ O₂ ) has been widely applied in numerous catalytic processes; however, such molybdate ions cannot be administered for redox-based cancer therapeutics. This work reports the albumin-mediated biomimetic synthesis of highly active molybdenum sulfide (denoted MoB) nanocatalysts that mediate the simultaneous generation of ¹ O₂ and superoxide anion (O₂ ^•- ) from H₂ O₂ , which is relatively abundant in malignant tumors. The MoB-catalyzed reactive oxygen species (ROS) are able to activate the ferroptosis pathway and cause lipid peroxidation for efficient cancer therapy. Furthermore, for the first time, the catalytic activity of MoB is visualized in situ. Moreover, a catalytic imaging modality based on MoB is developed for specific imaging of inflammation diseases without background interference. Therefore, this study presents a biomimetic strategy toward Mo-based nanocatalysts for ROS-facilitated tumor ferroptosis and catalytic imaging.

Gram-scale preparation of quercetin supramolecular nanoribbons for intestinal inflammatory diseases by oral administration

Gastrointestinal (GI) tract, which possesses the largest surface area of mucosa in the body, is easily suffered from inflammatory damages under the exposure of external stimulations. Excessive reactive oxygen species (ROS) production and continuous oxidative stress in intestines can elicit local mucosal injury, accelerate mucosal ulceration, and amplify the inflammatory response. Thereby, antioxidant therapy is a potential strategy against intestinal inflammatory diseases. Herein, we demonstrate the gram-scale preparation of quercetin supramolecular nanoribbons (SNRs) by using free quercetin molecules as the sole building block for preventing and treating intestinal inflammatory diseases. Unlike current clinical medicines, which mainly confront with poor response and severe adverse effects via bloodstream delivery, our quercetin SNRs possess an excellent antioxidant activity in the harsh environments of GI tract, a relative long retention time in GI tract, an admirable metabolism in GI tract without burdening other organs, and a specific adhesion to the inflamed intestinal epithelium via electrostatic interactions. These advantages strongly guarantee the applications of quercetin SNRs as oral medicines for intestinal inflammatory diseases. After establishing the models of intestinal inflammatory diseases caused by irradiation and drug stimulations, our quercetin SNRs exhibit the promising protective and therapeutic effects for radiation-induced acute enteritis and dextran sulfate sodium (DSS)-induced acute colitis. Because the super easy and fast preparation procedure and the nearly 100% loading capacity of quercetin SNRs, the current work provides a supramolecular nanomedicine with great clinical translation potential against intestinal inflammatory diseases.

Sex-specific colonic mitochondrial dysfunction in the indomethacin-induced inflammatory bowel disease model in rats

Introduction

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract and encompasses Crohn's disease and ulcerative colitis. Women appear to have more severe and recurring symptoms of IBD compared to men, most likely due to hormonal fluctuations. Studies have shown that mitochondrial dysfunction plays a role in the development of inflammation and there is evidence of colon mitochondrial alterations in IBD models and patients. In this study we have identified the presence of sex-specific colon mitochondrial dysfunction in a rat model of IBD.

Methods

Eight-week-old male and female rats were treated with indomethacin to induce IBD and mitoTEMPO was administered daily either after or before induction of IBD and until euthanasia. Colons were collected for histology and mitochondrial experiments. Intact mitochondrial respiration, reactive oxygen species (mtROS), the activities of the individual electron transport complexes and the activities of the antioxidant enzymes were measured to assess mitochondrial function.

Results

IBD male rats showed a decrease in citrate synthase activity, cardiolipin levels, catalase activity and an increase in mtROS production. IBD females show a decrease in intact colon mitochondrial respiration, colon mitochondria respiratory control ratio (RCR), complex I activity, complex IV activity, and an increase in mtROS. Interestingly, control females showed a significantly higher rate of complex I and II-driven intact mitochondrial respiration, MCFA oxidation, complex II activity, complex III activity, and complex IV activity compared to control males. The use of a mitochondrial-targeted therapy, mitoTEMPO, improved the disease and colon mitochondrial function in female IBD rats. However, in the males there was no observed improvement, likely due to the decrease in catalase activity.

Conclusions

Our study provides a better understanding of the role mitochondria in the development of IBD and highlights sex differences in colon mitochondrial function. It also opens an avenue for the development of strategies to re-establish normal mitochondrial function that could provide more options for preventive and therapeutic interventions for IBD.

Surface design of nanocarriers: Key to more efficient oral drug delivery systems

As nanocarriers (NCs) can improve the solubility of drugs, prevent their degradation by gastrointestinal (GI) enzymes and promote their transport across the mucus gel layer and absorption membrane, the oral bioavailability of these drugs can be substantially enhanced. All these properties of NCs including self-emulsifying drug delivery systems (SEDDS), solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), liposomes, polymeric nanoparticles, inorganic nanoparticles and polymeric micelles depend mainly on their surface chemistry. In particular, interaction with food, digestive enzymes, bile salts and electrolytes, diffusion behaviour across the mucus gel layer and fate on the absorption membrane are determined by their surface. Bioinert surfaces limiting interactions with gastrointestinal fluid and content as well as with mucus, adhesive surfaces providing an intimate contact with the GI mucosa and absorption enhancing surfaces can be designed. Furthermore, charge converting surfaces shifting their zeta potential from negative to positive directly at the absorption membrane and surfaces providing a targeted drug release are advantageous. In addition to these passive surfaces, even active surfaces cleaving mucus glycoproteins on their way through the mucus gel layer can be created. Within this review, we provide an overview on these different surfaces and discuss their impact on the performance of NCs in the GI tract.

COF-based artificial probiotic for modulation of gut microbiota and immune microenvironment in inflammatory bowel disease

Conventional strategies for treating inflammatory bowel disease merely relieve inflammation and excessive immune response, but fail to solve the underlying causes of IBD, such as disrupted gut microbiota and intestinal barrier. Recently, natural probiotics have shown tremendous potential for the treatment of IBD. However, probiotics are not recommended for IBD patients, as they may cause bacteremia or sepsis. Herein, for the first time, we constructed artificial probiotics (Aprobiotics) based on artificial enzyme-dispersed covalent organic frameworks (COFs) as the "organelle" and a yeast shell as the membrane of the Aprobiotics to manage IBD. The COF-based artificial probiotics, with the function of natural probiotics, could markedly relieve IBD by modulating the gut microbiota, suppressing intestinal inflammation, protecting the intestinal epithelial cells, and regulating immunity. This nature-inspired approach may aid in the design of more artificial systems for the treatment of various incurable diseases, such as multidrug-resistant bacterial infection, cancer, and others.

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.

Advances in Oral Drug Delivery Systems: Challenges and Opportunities

The oral route is the most preferred route for systemic and local drug delivery. However, the oral drug delivery system faces the harsh physiological and physicochemical environment of the gastrointestinal tract, which limits the bioavailability and targeted design of oral drug delivery system. Innovative pharmaceutical approaches including nanoparticulate formulations, biomimetic drug formulations, and microfabricated devices have been explored to optimize drug targeting and bioavailability. In this review, the anatomical factors, biochemical factors, and physiology factors that influence delivering drug via oral route are discussed and recent advance in conventional and novel oral drug delivery approaches for improving drug bioavailability and targeting ability are highlighted. We also address the challenges and opportunities of oral drug delivery systems in future.

Orally deliverable sequence-targeted astaxanthin nanoparticles for colitis alleviation

Orally targeted strategy of anti-inflammatory agents has attracted tremendous attention for reducing highly health-care costs and enhancing the intervention efficiency of ulcerative colitis (UC). Herein, we developed a new kind of sequence-targeted astaxanthin nanoparticles for UC treatment. Astaxanthin nanoparticles were firstly designed by self-assembly method using (3-carboxypentyl) (triphenyl) phosphonium bromide (TPP)-modified whey protein isolate (WPI)-dextran (DX) conjugates. Subsequently, lipoic acid (LA) modified hyaluronic acid (HA) was coated on the surface of the nanoparticles by double emulsion evaporation method. Exhilaratingly, the constructed sequence-targeted astaxanthin nanoparticle exhibited excellent macrophages and mitochondria targeting ability, with a Pearson's correlation coefficient of 0.84 adstnd 0.92, respectively. In vivo imaging elucidated an obvious accumulation of the sequence-targeted nanoparticles in colon tissues in UC mice. Meanwhile, the reduction stimulus release features of astaxanthin were observed in the presence of 10 mM of glutathione (GSH) at pH 7.4. Most importantly, in vivo experiments indicated that sequence-targeted astaxanthin nanoparticles could markedly alleviate inflammation by moderating the TLR4/MyD88/NF-κB signaling pathway. What's more, the composition of gut microbiota and the production of short chain fatty acid were also improved upon the uptake of sequence-targeted astaxanthin nanoparticles. Our results suggested this novel astaxanthin nanoparticles, which showed sequence-targeted ability and reduction response feature, could be exploited as a promising strategy for effective UC treatment.

Bioresponsive Immunotherapeutic Materials

The human immune system is an interaction network of biological processes, and its dysfunction is closely associated with a wide array of diseases, such as cancer, infectious diseases, tissue damage, and autoimmune diseases. Manipulation of the immune response network in a desired and controlled fashion has been regarded as a promising strategy for maximizing immunotherapeutic efficacy and minimizing side effects. Integration of "smart" bioresponsive materials with immunoactive agents including small molecules, biomacromolecules, and cells can achieve on-demand release of agents at targeted sites to reduce overdose-related toxicity and alleviate off-target effects. This review highlights the design principles of bioresponsive immunotherapeutic materials and discusses the critical roles of controlled release of immunoactive agents from bioresponsive materials in recruiting, housing, and manipulating immune cells for evoking desired immune responses. Challenges and future directions from the perspective of clinical translation are also discussed.

Deciphering the catalytic mechanism of superoxide dismutase activity of carbon dot nanozyme

Nanozymes with superoxide dismutase (SOD)-like activity have attracted increasing interest due to their ability to scavenge superoxide anion, the origin of most reactive oxygen species in vivo. However, SOD nanozymes reported thus far have yet to approach the activity of natural enzymes. Here, we report a carbon dot (C-dot) SOD nanozyme with a catalytic activity of over 10,000 U/mg, comparable to that of natural enzymes. Through selected chemical modifications and theoretical calculations, we show that the SOD-like activity of C-dots relies on the hydroxyl and carboxyl groups for binding superoxide anions and the carbonyl groups conjugated with the π-system for electron transfer. Moreover, C-dot SOD nanozymes exhibit intrinsic targeting ability to oxidation-damaged cells and effectively protect neuron cells in the ischemic stroke male mice model. Together, our study sheds light on the structure-activity relationship of C-dot SOD nanozymes, and demonstrates their potential for treating of oxidation stress related diseases.

ROS-triggered self-disintegrating and pH-responsive astaxanthin nanoparticles for regulating the intestinal barrier and colitis

Smart delivery systems with stimuli-responsive capability are able to improve the bioaccessibility through increasing the solubility, physicochemical stability and biocompatibility of bioactive compounds. In this study, the astaxanthin nanoparticles with reactive oxygen species (ROS) and pH dual-response function were design and constructed using poly (propylene sulfide) covalently modified sodium alginate as carriers based on ultrasonic assisted self-assembly strategy. Atomic force microscope and scanning electron microscope analysis showed that the nanoparticles were spherical in shape with a size of around 260 nm. Meanwhile, the astaxanthin nanoparticles showed both pH and ROS stimuli-responsive release characteristics. In vitro cell experiments showed that astaxanthin nanoparticles significantly inhibited the production of ROS and mitochondrial depolarization induced by oxidative stress. In vivo colitis experiment of mice revealed that astaxanthin nanoparticles could significantly relieve colitis, protect the integrity of colon tissue and restore the expression of tight junction proteins ZO-1 and occludin. The abundance of Lactobacillus and Lachnospiraceae, and the ratio of Firmicutes/Bacteroidota of gut microbiota were significantly improved after intervention of the stimuli-responsive astaxanthin nanoparticles. This work provided a simple strategy for constructing ROS/pH dual response delivery system, which provided an experimental basis for improving the oral bioavailability of hydrophobic active compounds.

Pathologically triggered in situ aggregation of nanoparticles for inflammation-targeting amplification and therapeutic potentiation

Uncontrolled and persistent inflammation is closely related to numerous acute and chronic diseases. However, effective targeting delivery systems remain to be developed for precision therapy of inflammatory diseases. Herein we report a novel strategy for engineering inflammation-accumulation nanoparticles via phenolic functionalization. Different phenol-functionalized nanoparticles were first developed, which can undergo in situ aggregation upon triggering by the inflammatory/oxidative microenvironment. Phenolic compound-decorated poly (lactide-co-glycolide) nanoparticles, in particular tyramine (Tyr)-coated nanoparticles, showed significantly enhanced accumulation at inflammatory sites in mouse models of colitis, acute liver injury, and acute lung injury, mainly resulting from in situ cross-linking and tissue anchoring of nanoparticles triggered by local myeloperoxidase and reactive oxygen species. By combining a cyclodextrin-derived bioactive material with Tyr decoration, a multifunctional nanotherapy (TTN) was further developed, which displayed enhanced cellular uptake, anti-inflammatory activities, and inflammatory tissue accumulation, thereby affording amplified therapeutic effects in mice with colitis or acute liver injury. Moreover, TTN can serve as a bioactive and inflammation-targeting nanoplatform for site-specifically delivering a therapeutic peptide to the inflamed colon post oral administration, leading to considerably potentiated in vivo efficacies. Preliminary studies also revealed good safety of orally delivered TTN. Consequently, Tyr-based functionalization is promising for inflammation targeting amplification and therapeutic potentiation of nanotherapies.

Emerging Nanotechnologies and Microbiome Engineering for the Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is characterized by the chronic inflammation of the gastrointestinal tract and impacts almost 7 million people across the globe. Current therapeutics are effective in treating the symptoms, but they often do not address the root cause or selectively target areas of inflammation. Notably, self-assembled nanoparticles show great promise as drug delivery systems for the treatment of IBD. Nanoparticles can be designed to survive the harsh gastric conditions and reach inflamed areas of the gastrointestinal tract. Oral drug delivery with nanoparticles can localize drugs to the impacted inflamed region using active and/or passive targeting and promote a high rate of drug dispersion in local tissues, thus reducing potential off-target toxicities. Since a dysregulated gut microbiome is implicated in the development and progression of IBD, it is also important to develop nanoparticles and biomaterials that can restore symbiotic microbes while reducing the proliferation of harmful microbes. In this review, we highlight recent advances in self-assembled nanosystems designed for addressing inflammation and dysregulated gut microbiomes as potential treatments for IBD. Nanoparticles have a promising future in improving the delivery of current therapeutics, increasing patient compliance by providing an oral method of medication, and reducing side effects. However, remaining challenges include scale-up synthesis of nanoparticles, potential side effects, and financial obstacles of clinical trials. It would be in the patients' best interest to continue research on nanoparticles in the pursuit of more effective therapeutics for the treatment of IBD.

Functionally integrating nanoparticles alleviate deep vein thrombosis in pregnancy and rescue intrauterine growth restriction

There is still unmet demand for effective, safe, and patient-friendly anti-thrombotics to treat deep vein thrombosis (DVT) during pregnancy. Here we first engineer a bioactive amphiphile (TLH) by simultaneously conjugating Tempol and linoleic acid onto low molecular weight heparin (LMWH), which can assemble into multifunctional nanoparticles (TLH NP). In pregnant rats with DVT, TLH NP can target and dissolve thrombi, recanalize vessel occlusion, and eradicate the recurrence of thromboembolism, thereby reversing DVT-mediated intrauterine growth restriction and delayed development of fetuses. Mechanistically, therapeutic effects of TLH NP are realized by inhibiting platelet aggregation, facilitating thrombolysis, reducing local inflammation, attenuating oxidative stress, promoting endothelial repair, and increasing bioavailability. By decorating with a fibrin-binding peptide, targeting efficiency and therapeutic benefits of TLH NP are considerably improved. Importantly, LMWH nanotherapies show no toxicities to the mother and fetus at the dose 10-time higher than the examined therapeutic dosage.

Targeting pathophysiological changes using biomaterials-based drug delivery systems: A key to managing inflammatory bowel disease

Inflammatory bowel disease (IBD) is a gastrointestinal disorder, affecting about several million people worldwide. Current treatments fail to adequately control some clinical symptoms in IBD patients, which can adversely impact the patient's quality of life. Hence, the development of new treatments for IBD is needed. Due to their unique properties such as biocompatibility and sustained release of a drug, biomaterials-based drug delivery systems can be regarded as promising candidates for IBD treatment. It is noteworthy that considering the pathophysiological changes occurred in the gastrointestinal tract of IBD patients, especially changes in pH, surface charge, the concentration of reactive oxygen species, and the expression of some biomolecules at the inflamed colon, can help in the rational design of biomaterials-based drug delivery systems for efficient management of IBD. Here, we discuss about targeting these pathophysiological changes using biomaterials-based drug delivery systems, which can provide important clues to establish a strategic roadmap for future studies.

Annexin A1 based inflammation resolving mediators and nanomedicines for inflammatory bowel disease therapy

Inflammatory bowel diseases (IBD) such as Crohn's Disease (CD) and Ulcerative Colitis (UC) are chronic, progressive, and relapsing disorders of the gastrointestinal tract (GIT), characterised by intestinal epithelial injury and inflammation. Current research shows that in addition to traditional anti-inflammatory therapy, resolution of inflammation and repair of the epithelial barrier are key biological requirements in combating IBD. Resolution mediators include endogenous lipids that are generated during inflammation, e.g., lipoxins, resolvins, protectins, maresins; and proteins such as Annexin A1 (ANXA1). Nanoparticles can specifically deliver these potent inflammation resolving mediators in a spatiotemporal manner to IBD lesions, effectively resolve inflammation, and promote a return to homoeostasis with minimal collateral damage. We discuss these exciting and timely concepts in this review.

Mucus-Penetrating Silk Fibroin-Based Nanotherapeutics for Efficient Treatment of Ulcerative Colitis

Oral nanoparticles have been considered a prospective drug delivery carrier against ulcerative colitis (UC). To enhance the mucus-penetrating capacity and aqueous solubility, and strengthen the anti-inflammatory effect of resveratrol (RSV), we fabricated RSV-loaded silk fibroin-based nanoparticles with the functionalization of Pluronic F127 (PF-127). The obtained PF-127-functionalized RSV-loaded NPs had an average particle size around 170 nm, a narrow size distribution (polydispersity index < 0.2), and negative zeta potential (−20.5 mV). Our results indicated that the introduction of PF-127 strengthened the mucus-penetrating property of NPs. In vitro studies suggested that NPs with PF-127 enhanced the suppression of the secretion of proinflammatory cytokine TNF-α and reactive oxygen species (ROS) from RAW 264.7 macrophages under lipopolysaccharide stimulation in comparison with other counterparts. According to the evaluation of macro symptoms and main inflammatory cytokines, we further report preferable therapeutic outcomes achieved by PF-127 functionalized-NP-treated dextran sulphate sodium (DSS) groups in the colitis model compared with blank silk fibroin NPs and RSV-loaded NPs without the functionalization of PF-127. Taken together, this work suggests that the fabricated PF-127 NPs via the oral route are promising and useful RSV-loaded nanocarriers for UC treatment.

Pathological features-based targeted delivery strategies in IBD therapy: A mini review

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is characterized by a complex and dysfunctional immune response. Currently, IBD is incurable, and patients with IBD often need to take drugs for life. However, as the traditional systemic treatment strategies for IBD do not target the site of inflammation, only limited efficacy can be obtained from them. Moreover, the possibility of serious side effects stemming from the systemic administration or redistribution of drugs in the body is high when conventional drug formulations are used. Therefore, a targeted drug-delivery system for IBD should be considered. Based on the pathological features related to IBD, the new targeted drug-delivery strategy can directly transfer the drug to the inflammatory site, thus enhancing the accumulation of the drugs and reducing side effects. This article reviews the pathological features of IBD and the application of the IBD-targeted delivery system based on different pathological features, and discusses the challenges and new prospects in this field.

N-acetylneuraminic acid and chondroitin sulfate modified nanomicelles with ROS-sensitive H2S donor via targeting E-selectin receptor and CD44 receptor for the efficient therapy of atherosclerosis

Currently, very limited therapeutic approaches are available for the drug treatment of atherosclerosis(AS). H2S-donor is becoming a common trend in much life-threatening research. Several studies have documented that H2S-lyase is predominantly present in endothelial cells. N-Acetylneuraminic acid (SA), natural carbohydrate, binds specifically to the E-selectin receptor of endothelial cells. Meanwhile, recent studies related to Chondroitin sulfate have excellent target binding ability with CD44 receptor. We conjecture that the N-Acetylneuraminic acid and Chondroitin sulfate modified nanomicelles not only enhances the accumulation of the drug but also cleaves the H2S donor in the lesion, thus one stone two birds. Given these findings, we synthesized two kinds of nanoparticles, Carrier I (SCCF) and Carrier II (SCTM), for atherosclerosis to validate our guesses. Initially, S-allyl-L-cysteine and 4-methoxyphenylthiourea were used as H2S donors for SCCF and SCTM, respectively. After the introduction of ROS-sensitive groups. Then, micelles with N-Acetylneuraminic acid and Chondroitin sulfate were prepared to load rapamycin(RAP). Further, in atherosclerosis Oil Red O staining (ORO) results confirmed remarkable treatment effect with SCCF@RAP and SCTM@RAP. Thus, we conclude that the effect of dual-targeting nanomicelles with ROS-sensitive H2S donor based on N-Acetylneuraminic acid and Chondroitin sulfate will have a better role in atherosclerosis.

ROS-triggered nanoinducer based on dermatan sulfate enhances immunogenic cell death in melanoma

Due to its complexity, diversity and heterogeneity, melanoma is a kind of malignant tumor. It has been proved that the enhancement of anti-tumor immune response such as immunogenic cell death (ICD) is an important therapeutic strategy. In previous studies, we confirmed that dermatan sulfate (DS) from skin tissue could specifically homing to melanoma B16F10 cells. In this study, we propose a nanoinducer (DOX/ADS NP) based on a functional DS for melanoma. This nanosystem is composed of DS as framework, aromatic thioketal derivative (ATK) as functional grafting unit and doxorubicin (DOX) designed as an ICD inducer. Through the intermolecular interaction between DOX and ATK, DOX/ADS NP with specific-homing, high-loading and ROS-triggering release was obtained via self-assemble. Compared with free DOX and non-functionalized nanomedicine, DOX/ADS NP could release DOX into B16F10 cells better, and strongly induce the translocation of calreticulin (CRT) to the cell membrane. CRT is a marker of ICD, also as a "eat me" signal to stimulate the maturation and antigen presentation of dendritic cells. Therefore, a series of subsequent immune responses were activated: maturation of dendritic cells, T cells proliferation, increased tumor-infiltrating CTLs and the ratio of CTLs to Tregs, and up-regulated cytotoxic cytokine expression. In conclusion, DOX/ADS NP promoted ICD-associated immune response through more specific targeting effect and sensitive responsive DOX release, achieving better inhibitory effect on melanoma than free DOX and other nanoformulation. This biomimetic ICD nanoinducer based on DS is expected to provide new strategies and references for the treatment of melanoma.