Orally Administrated Inflamed Colon-Targeted Nanotherapeutics for Inflammatory Bowel Disease Treatment by Oxidative Stress Level Modulation in Colitis

Orally-deliverable liposome-microgel complexes dynamically remodel intestinal environment to enhance probiotic ulcerative colitis therapy via TLR4 inhibition and tryptophan metabolic crosstalk

Probiotics emerges as a promising option for ulcerative colitis (UC) treatment, but its application remains challenging due to insufficient colon-targeted delivery efficiency and survival against the inflammation-associated intestinal oxidative stress. To address these issues, here we report a supramolecular liposome-microgel complex (SLMC) incorporated with Bacillus subtilis spores (BSSs) and dexamethasone (DEX) for orally-deliverable probiotic UC therapy. Specifically, BSSs and cholesterols were conjugated with gelatin via diselenide ligation to prepare microgels, followed by supramolecular complexation with UC-targeted DEX-loaded liposome via microfluidic engineering. The orally-administered SLMC efficiently accumulated in UC-affected colonic sites to release BSSs and DEX. DEX elicited rapid anti-inflammatory effect to reduce ROS generation, which cooperated with the ROS consumption by spore germination and diselenide cleavage to orchestrate an anaerobic intestinal microenvironment, thus promoting Bacillus subtilis colonization to restore gut homeostasis and initiate anti-inflammatory microbiota-macrophage metabolic crosstalk. Indeed, in vivo analysis showed that the SLMC treatment markedly inhibited pro-inflammatory TLR4-NF-κB signaling activities in mucosal macrophages through localized DEX delivery and boosting tryptophan metabolite production, leading to robust and durable UC abolishment. This study offers a practical approach for improving UC treatment in the clinic.

Nanozyme-functionalized microalgal biohybrid microrobots in inflammatory bowel disease treatment

Oral drugs are the most direct and effective strategy for the treatment of gastrointestinal diseases. However, the harsh environment of gastric juice, lack of targeted lesion sites, and rapid metabolism present difficulties in the development of oral drugs. This research introduces a nanozyme-functionalized microalgal biohybrid microrobot (Hp@CS-PNAs@PAA) with a novel mechanism for treating inflammatory bowel disease (IBD) by leveraging the therapeutic advantages of microalgae and nanozymes. The microrobot uniquely combines the natural antioxidant capacity of Hematococcus pluvialis (Hp) microalgae and the catalytically active enzyme-mimicking properties of platinum-based nanoparticle assemblies (PNAs), enabling enhanced scavenging of reactive oxygen species (ROS) and targeted anti-inflammatory effects. Through its layered design, the Hp@CS-PNAs@PAA microrobot can navigate the gastrointestinal tract, resist degradation, and target inflamed colon tissues via electrostatic interactions, achieving extended retention and prolonged therapeutic action at inflammation sites. This study demonstrated that the synergistic anti-inflammatory effects of the microrobot derive from its ability to reduce ROS, inhibit proinflammatory cytokines, and promote the expression of tight junction proteins critical for preserving the integrity of the intestinal barrier. Both in vitro and in vivo tests in a DSS-induced colitis mouse model revealed that this system effectively restores damaged tissues by reducing oxidative stress and inflammation, indicating significant potential for clinical application in the management of colitis and similar inflammatory diseases.

How Do Organelle-Targeting Nanotherapeutics Treat Inflammatory Diseases? A Comprehensive Review of the Literature

Inflammation is a protective response of the body, but when excessive or prolonged, it can contribute to disease progression and tissue damage. Identifying more effective and less toxic drugs for treating both acute and chronic inflammatory diseases is a major challenge. Organelle-targeting strategies, which deliver drugs directly to specific organelles, offer a promising solution by improving treatment efficiency and minimizing toxic effects on healthy cells. However, despite the potential of organelles as therapeutic targets, precise targeting remains challenging. This review systematically summarizes organelle-targeting nanodelivery strategies for major organelles-mitochondria, the endoplasmic reticulum, lysosomes, and the Golgi apparatus-and the research progress in evaluating the potential of these strategies for treating inflammation-related diseases. This study focuses on the applications of these strategies for the treatment of sepsis, inflammatory bowel disease, atherosclerosis, and osteoarthritis. Additionally, this review outlines future directions and key challenges in this field, aiming to provide a scientific reference for the application of organelle-targeting nanotherapeutics for the treatment of inflammatory diseases.

Orally Administered ZnxCeyO2/Se Hydrogel with Effective Antioxidant Activity for Treating Inflammatory Bowel Disease by Inhibiting Ferroptosis

Oxidative stress leads to intestinal barrier damage, which induces immune responses to occur and further promotes oxidative stress exacerbating inflammatory bowel disease (IBD). In this work, the multifunctional ZnxCeyO2/Se (ZCSO) nanozyme wrapped with acid-resistant calcium alginate hydrogel designed for oral administration is prepared. The ZCSO nanozyme can promote the activation of the Nrf2 oxidative stress pathway, then significantly improve the efficiency of scavenging reactive oxygen species (ROS) and up-regulate the protein expression of glutathione peroxidase 4 (GPx4), which is closely related to the inhibition of ferroptosis. In addition, the ZCSO nanozyme inhibiting the growth of some pathogenic bacteria proliferating due to oxidative stress shows a positive regulation of the intestinal flora and reduces the secretion of pro-inflammatory factors and the levels of inflammatory macrophages, achieving the significant preventive and delayed therapeutic effect of colitis mice. Consequently, the distinctive properties of ZCSO nanozyme render it a promising candidate for the treatment of IBD by effectively scavenging ROS, thereby interrupting the detrimental cycle between oxidative stress and immune response, ultimately promoting the proliferation of epithelial cells to reestablish the integrity of the intestinal mucosal barrier.

Advanced oral drug delivery systems for gastrointestinal targeted delivery: the design principles and foundations

Oral administration has long been considered the most convenient method of drug delivery, requiring minimal expertise and invasiveness. Unlike injections, it avoids discomfort, wound infections, and complications, leading to higher patient compliance. However, the effectiveness of oral delivery is often hindered by the harsh biological barriers of the gastrointestinal tract, which limit the bioaccessibility and bioavailability of drugs. The development of oral drug delivery systems (ODDSs) represents a critical area for the advancement of pharmacotherapy. This review highlights the characteristics and precise targeting mechanisms of ODDSs. It first examines the unique properties of each gastrointestinal compartment, including the stomach, small intestine, intestinal mucus, intestinal epithelial barrier, and colon. Based on these features, it outlines the targeting strategies and design principles for ODDSs aimed at overcoming gastrointestinal barriers to enhance disease treatment. Lastly, the review discusses the challenges and potential future directions for ODDS development, emphasizing their importance for advancing drug delivery technologies and accelerating their future growth.

Nanocatalytic Therapy for Pneumonia by a Hetero-Element-Doped Carbon Nanozyme

Pneumonia continues to be complicated by its progression to acute lung injury (ALI). The onset of ALI is linked to an overproduction of reactive oxygen species (ROS) and a severe inflammatory response. Therefore, the rapid mitigation of ROS and inflammation is crucial in addressing ALI. Concurrently, prompt bacterial elimination is necessary for bacteria-induced ALI. Here, a Co-based carbon nanozyme (CN) with enhanced enzyme-like activities is developed by co-doping with a small amount of Mn (CoMn CN). Compared to cobalt CN without Mn co-doping (Co CN), the active sites of Co and its coordination with N in CoMn CN are slightly altered, resulting in enhanced oxidase (OXD)-, peroxidase (POD)-, superoxide dismutase (SOD)-, and catalase (CAT)-like activities. Given the enhanced enzyme-like activities, its applications for lipopolysaccharide (LPS)- and methicillin-resistant Staphylococcus aureus (MRSA)-induced ALI treatments are explored. CoMn CN demonstrates superior efficacy in both LPS- and MRSA-induced ALI models, effectively combining rapid scavenging of ROS and inflammation with subsequently bacterial elimination. Consequently, a novel type of Co-based CN by Mn co-doping is developed to augment enzyme-like activities, offering significant protective effects against ALI. This study not only broadens the application of Co-based CNs but also shows a promising strategy for ALI therapy.

Immune modulation for the patterns of epithelial cell death in inflammatory bowel disease

Inflammatory bowel disease (IBD) is an inflammatory disease of the intestine whose primary pathological presentation is the destruction of the intestinal epithelium. The intestinal epithelium, located between the lumen and lamina propria, transmits luminal microbial signals to the immune cells in the lamina propria, which also modulate the intestinal epithelium. In IBD patients, intestinal epithelial cells (IECs) die dysfunction and the mucosal barrier is disrupted, leading to the recruitment of immune cells and the release of cytokines. In this review, we describe the structure and functions of the intestinal epithelium and mucosal barrier in the physiological state and under IBD conditions, as well as the patterns of epithelial cell death and how immune cells modulate the intestinal epithelium providing a reference for clinical research and drug development of IBD. In addition, according to the targeting of epithelial apoptosis and necroptotic pathways and the regulation of immune cells, we summarized some new methods for the treatment of IBD, such as necroptosis inhibitors, microbiome regulation, which provide potential ideas for the treatment of IBD. This review also describes the potential for integrating AI-driven approaches into innovation in IBD treatments.

Self-assembly pH-sensitive polyelectrolyte complex co-delivers niclosamide and colistin to overcome colistin resistance in bacterial infections

Polyelectrolyte complexes (PECs) provided new opportunities for drug-controlled release systems and had the potential to address the challenges during the effective oral delivery of colistin and niclosamide. Here, an innovative pH-sensitive PEC for the oral co-delivery of colistin and niclosamide (CS/AL-PECs@COL/NIC) was developed, which was self-assembled through electrostatic interaction by an optimized double-emulsion method from two oppositely charged nanoparticles (chitosan-coated nanoparticles and alginate-coated nanoparticles). The CS/AL-PECs@COL/NIC exhibited pH sensitivity, formed a tight cross-linked structure in the gastric acid environment, effectively slowing down the release of the loaded drugs (colistin and niclosamide), and transformed into a loose structure in the neutral environment of the intestine, facilitating the stable release of the loaded drugs. Importantly, the CS/AL-PECs@COL/NIC had good in vivo antibacterial activity against E. coli infection and alleviated the inflammation and intestinal damage caused by bacterial infection in the mouse intestinal infection model. Both in vitro and in vivo studies indicated that the CS/AL-PECs@COL/NIC had good biocompatibility and good palatability. In particular, the oral administration of an effective dose of CS/AL-PECs@COL/NIC did not cause intestinal flora disorder, which had an advantage over colistin treatment. Thus, the prepared CS/AL-PECs@COL/NIC may contribute to treating colistin-resistant bacterial infections as a biocompatible oral administration.

Broad-Spectrum ROS/RNS Scavenging Catalase-Loaded Microreactors for Effective Oral Treatment of Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) such as ulcerative colitis (UC) is an autoimmune disease characterized by persistent inflammation along the gastrointestinal tract with excessive generation of reactive oxygen species (ROS)/reactive nitrogen species (RNS) generation. Here, catalase (CAT)-containing microreactor capsules with long-lasting broad-spectrum ROS/RNS-scavenging capability are developed for the treatment of IBD. In this design, CAT is encapsulated in the dense hydrogel network of calcium alginate (ALG) microspheres, which provides long-term protection of CAT activity in protease-rich intestinal environment. Afterward, the polydopamine (PDA) modification on the surface of CAT@ALG microspheres can provide them bioadhesiveness to achieve prolonged retention in the intestinal tract and broad-spectrum scavenging capability against various types of ROS/RNS beyond hydrogen peroxide. Enteric capsules are further used to protect the CAT@ALG-PDA microspheres from gastric fluid for selective release at the intestinal site. The combined action of PDA and CAT in CAT@ALG-PDA microreactors results in the broad-spectrum scavenging of excess ROS/RNS and regulates redox balance in acute UC rat model, showing satisfactory therapeutic effects superior to the mesalazine and adalimumab at clinically relevant doses without obvious side effects. This work highlights that these CAT@ALG-PDA capsules can act as long-acting broad-spectrum ROS/RNS reactors, promising for IBD treatment.

Triple-Functional Probiotics with Intracellularly Synthesized Selenium Nanoparticles for Colitis Therapy by Regulating the Macrophage Phenotype and Modulating Gut Microbiota

The dysregulated macrophage phenotype, as the main cause of colitis, not only enhanced oxidative stress to exacerbate inflammatory responses but was closely related with gut microbial dysbiosis. It was needed to simultaneously address the three issues for the effective treatment of colitis, but it was not satisfied. Here, we developed "three-birds-one-stone" probiotics, named Se@EcN-C2/A2, for colitis treatment. Escherichia coli Nissle 1917 (EcN), a clinically approved probiotic, was used to intracellularly synthesize selenium (Se) nanoparticles by biomineralization, giving Se@EcN. Coating glycol chitosan and sodium alginate on the surface of Se@EcN (Se@EcN-C2/A2) endowed probiotics with high resistance to the harsh gastrointestinal tract environment and strong adhesion and targeting ability to the inflamed site of the colon to facilitate the uptake by M1 macrophages. Se@EcN-C2/A2 was metabolized to SeCys2 and MetSeCys to be involved in the synthesis of GPX2 and TXNRD1, which led to reaction oxygen species clearance to inhibit Toll-like receptor and nuclear factor κB signaling pathways to suppress inflammatory response and polarize M1 macrophages to M2 phenotypes by activating PI3K/AKT signaling pathways. In DSS-induced colitis mice, Se@EcN-C2/A2 exerted satisfactory therapeutic and prophylactic effects, including scavenging oxidative stress and regulating macrophage phenotypes to suppress inflammatory response and restore gut barrier functions. Moreover, the living probiotic EcN in the colon effectively regulated microbial dysbiosis by decreasing the abundance of Escherichia-Shigella and increasing the abundance of Lactobacillus and Bifidobacterium.

Bioinspired Suction-Driven Strategies with Nanoscale Skin-Controllable Adhesive Architectures for Efficient Liquid Formulated Transdermal Patches

For highly efficient and precise drug release, transdermal drug delivery systems (TDDS) have recently evolved through the combination of intelligent material-based structures with various active components. These strategies are an effort to overcome the significant difficulties in delivering large molecule drugs and nanomaterials due to the physical barrier of the skin, especially the stratum corneum, in traditional TDDS. Interestingly, multiscale suction-driven architectures (SDAs) inspired by bioinspired suction adhesion mechanisms have provided innovative solutions to these challenges. These architectures employ negative pressure to enhance nanoscale skin-controllable skin adhesion, temporarily bypass the skin barrier, and facilitate deep penetration of therapeutic agents, thereby, achieving the goals of increasing drug delivery efficiency and maximizing user convenience as a minimal invasive, needle-free platform. This review provides a comprehensive overview of suction-driven transdermal patches and emphasizes their integration with multifunctional materials to achieve stable adhesion and controlled drug release. Next, we present cost-effective and user-friendly suction-driven drug delivery patch devices through optimization of cupping structures without the incorporation of additional devices. Furthermore, we present cost-effective and user-friendly transdermal drug delivery patch devices that optimize multiscale cupping architectures without the need for additional devices. Potential of bioinspired SDAs in localized and systemic drug delivery through challenging and complex skin, as well as future perspectives, are discussed, along with innovative directions for more efficient and patient-centric transdermal drug delivery solutions.

"Shield" Armed Programmable Probiotics Harboring α-Aminoadipate Aminotransferase Gene Regulate Tryptophan Metabolism and Gut Microbiota to Alleviate the Inflammatory Bowel Disease

Current treatment of inflammatory bowel disease (IBD) relies on anti-inflammatory and immunosuppressive agents. However, this concept is considered outdated due to its restricted efficacy and unavoidable side effects. Herein, a polynorepinephrine-coated programmable probiotic expressing α-aminoadipate aminotransferase (NE-EcN-pA) was constructed to improve the levels of kynurenic acid and xanthurenic acid in the intestine by modulating the endogenous tryptophan metabolism. The NE layer could protect EcN-pA against the harsh environment of the gastrointestinal tract, enhancing its survival and colonization. In UC mice, oral administration of NE-EcN-pA effectively alleviated intestinal inflammation and restored the intestinal epithelial barrier owing to the activation of the aryl hydrocarbon receptor pathway. Furthermore, NE-EcN-pA promoted the diversity of intestinal flora, improved the imbalance of flora, and enhanced the content of short-chain fatty acids in the colon. Overall, NE-EcN-pA can regulate endogenous tryptophan metabolism and gut microbiota, showing promise in the treatment of gastrointestinal disorders.

Functional anti-inflammatory mesoporous silica nanoplatform for Synergistic and Targeted abdominal aortic aneurysm treatment

Abdominal aortic aneurysm (AAA) is a chronic inflammation-driven disease characterized by aortic wall destruction and expansion, leading to high morbidity and mortality. However, previous drug treatments for its common risk factors have not achieved favorable results, and the early prevention and treatment is still the main clinical dilemma. Anti-inflammation therapy is a promising therapeutical method targeting its pathogenesis mechanism, but it has not been explored in depth. Herein, interleukin-1 receptor antagonist-loaded manganese-doped mesoporous silica nanoparticles (IL-1Ra@MMSN) were designed and synthesized to target macrophage-mediated chronic aortic inflammation for AAA treatment. IL-1Ra@MMSN showed high IL-1Ra-loading efficiency, great stability and pH-responsive drug-releasing property. IL-1Ra@MMSN specially phagocytosed by macrophages can protect against oxidative stress injury and promoted the M2 polarization via transforming growth factor-β (TGF-β) signaling in vitro. Furthermore, IL-1Ra@MMSN exhibited good lesion targeting ability, hemocompatibility and biocompatibility in angiotensin II-induced murine AAA model. In vivo experiments also confirmed the excellent treatment efficacy in reducing AAA formation and progression via protecting aortic wall integrity and promoting anti-inflammatory microenvironment. Taken together, the current study demonstrated that IL-1Ra@MMSN is a promising nanoplatform for early intervention of AAA, which provides a novel treatment strategy based on anti-inflammatory immune regulation.

Gut Microbiota Modulation in IBD: From the Old Paradigm to Revolutionary Tools

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders primarily comprising two main conditions: ulcerative colitis and Crohn's disease. The gut microbiota's role in driving inflammation in IBD has garnered significant attention, yet the precise mechanisms through which the microbiota influences IBD pathogenesis remain largely unclear. Given the limited therapeutic options for IBD, alternative microbiota-targeted therapies-including prebiotics, probiotics, postbiotics, and symbiotics-have been proposed. While these approaches have shown promising results, microbiota modulation is still mainly considered an adjunct therapy to conventional treatments, with a demonstrated impact on patients' quality of life. Fecal microbiota transplantation (FMT), already approved for treating Clostridioides difficile infection, represents the first in a series of innovative microbiota-based therapies under investigation. Microbial biotherapeutics are emerging as personalized and cutting-edge tools for IBD management, encompassing next-generation probiotics, bacterial consortia, bacteriophages, engineered probiotics, direct metabolic pathway modulation, and nanotherapeutics. This review explores microbial modulation as a therapeutic strategy for IBDs, highlighting current approaches and examining promising tools under development to better understand their potential clinical applications in managing intestinal inflammatory disorders.

Biosilicification-mimicking chiral nanostructures for targeted treatment of inflammatory bowel disease

The cascade reaction of lipopolysaccharides (LPS), cell-free DNA (cfDNA), and reactive oxygen species (ROS), drives the development of inflammatory bowel disease (IBD). Herein, we construct polyethylenimide (PEI)-L/D-tartaric acid (L/D-TA) complexes templated mesoporous organosilica nanoparticles (MON) (PEI-L/D-TA@MON) by mimicking biosilicification under ambient conditions within seconds. The chiral nanomedicines include four functional moieties, wherein PEI electrostatically attracts cfDNA, tetrathulfide bonds reductively react with ROS, silanol groups adsorb LPS, and L/D-TA enables chiral recognition and inflammatory localization. Following oral administration, PEI-L-TA@MON exhibiting preferential conformation stereoscopically matches with mucosa and anchors onto inflammatory intestine for lesion targeting. PEI-L-TA@MON eliminates LPS, ROS, and cfDNA, alleviating oxidative stress, inhibiting inflammatory cascade, and maintaining immune homeostasis to achieve IBD therapy. In addition, the rapid synthesis, low cost, energy-free preparation, negligible toxicity, satisfactory therapeutic effect, and facile conversion on therapeutic modes of PEI-L-TA@MON will bring changes for IBD treatment, providing research values and translational clinical prospects.

Precision therapeutics for inflammatory bowel disease: advancing ROS-responsive nanoparticles for targeted and multifunctional drug delivery

Inflammatory bowel disease (IBD) is a severe chronic intestinal disorder with a rising global incidence. Current therapies, including the delivery of anti-inflammatory drugs and probiotics, face significant challenges in terms of safety, stability, and efficacy. In IBD patients, the activity of antioxidant enzymes (e.g., superoxide dismutase, glutathione peroxidase, and glutathione reductase) is reduced at the site of intestinal inflammation, leading to the accumulation of reactive oxygen species (ROS). This accumulation damages the intestinal mucosa, disrupts tight junctions between cells, and compromises the integrity of the intestinal barrier, exacerbating IBD symptoms. Therefore, nanoparticles responsive to ROS and capable of mimicking antioxidant enzyme activity, such as boronates, polydopamine, sulfides, and metal nanozymes, have emerged as promising tools. These nanoparticles can respond to elevated ROS levels in inflamed intestinal regions and release drugs to effectively neutralize ROS, making them ideal candidates for IBD treatment. This review discusses the application of various ROS-responsive nanomaterial delivery systems in IBD therapy, highlights current challenges, and outlines future research directions. Furthermore, we explore the "layered programmable delivery" strategy, which combines ROS-responsive nanoparticles with pH-responsive and cell membrane-targeted nanoparticles. This strategy has the potential to overcome the limitations of single-mechanism targeted drug delivery, enabling multi-range and multi-functional treatment approaches that significantly enhance delivery efficiency, providing new insights for the future of localized IBD treatment.

Orally Administrated Precision Nanomedicine for Restoring the Intestinal Barrier and Alleviating Inflammation in Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) presents a significant challenge in healthcare, characterized by its chronicity and complex pathogenesis involving genetic, immune, and environmental factors. Current treatment modalities, including anti-inflammatory drugs, immunomodulators, and biologics, often lack sufficient efficacy and are accompanied by adverse effects, necessitating the urgent search for therapeutic approaches targeting mucosal barrier restoration and inflammation modulation. Precision nanomedicine emerges as a promising solution to directly address these challenges. This study introduces the development of a targeted sequential nanomedicine for precise IBD treatment. This innovative formulation combines a prodrug carrier containing quercetin to restore intestinal barrier integrity through the regulation of tight junctions and an anti-inflammatory agent dexamethasone acetate to alleviate inflammation. Surface modification with pectin enables colon-specific drug delivery, facilitated by degradation by colon-specific microbiota. Responsive drug release, controlled by reactive oxygen species-sensitive chemical bonds within the carrier, ensures both spatial and temporal accuracy. In vitro and in vivo investigations confirm the nanomedicine's favorable physicochemical properties, release kinetics, and therapeutic efficacy, elucidating potential underlying mechanisms. Oral administration of the nanomedicine shows promising results in restoring intestinal barrier function, reducing inflammation, and modulating the gut microbiota. Consequently, this study presents a promising nanomedicine candidate for advancing IBD treatment paradigms.

Orally Administrated Inulin-Modified Nanozymes for CT-Guided IBD Theranostics

Background

Inflammatory bowel disease (IBD) is a chronic inflammatory bowel disease with no clinical cure. Excessive production of reactive oxygen species (ROS) at the inflammatory sites leads to the onset and progression of IBD. And the current non-invasive imaging methods are not ideal for the diagnosis and monitoring of IBD.

Methods

Herein, we developed inulin (IN)-coated cerium oxide nanoparticles (CeO2@IN NPs) for treatment and monitoring of IBD guided by computed tomography (CT). The physicochemical properties, ROS scavenging ability and CT imaging capabilities of CeO2@IN were investigated in vitro. Moreover, the therapeutic and targeted inflammation imaging effects of CeO2@IN were validated in dextran sulfate sodium (DSS)-induced colitis model.

Results

CeO2@IN with catalase (CAT) and superoxide dismutase (SOD) capabilities effectively scavenged ROS, thus protecting the cells against oxidative stress. In colitis model mice, orally administered CeO2@IN successfully traversed the gastrointestinal tract to reach the colon under the protection of IN, and effectively reduced intestinal inflammation, thereby maintaining the intestinal epithelial integrity. Notably, CeO2@IN performed better than conventional CT contrast agents for gastrointestinal tract imaging, particularly in detecting the inflamed areas in the colon. In addition, CeO2@IN exhibited excellent biocompatibility in vitro and in vivo.

Conclusion

The study provided a novel integrated diagnostic and therapeutic tool for the treatment and monitoring of IBD, presenting great potential as a clinical application for IBD.

Classification of Nanomaterial Drug Delivery Systems for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, primarily arises from defects in the colonic barrier, imbalances of the gut microbiota, and immune response issues. These complex causes make it difficult to achieve a complete cure. Patients with IBD frequently experience recurrent abdominal pain and bloody diarrhea, while severe cases may result in intestinal obstruction, perforation, and cancer. Lifelong maintenance therapy may thus be needed to manage these symptoms; however, traditional IBD drugs, such as 5-aminosalicylic acid, glucocorticoids, immunosuppressants, and biological agents, are often associated with problems including poor solubility, instability, and ineffective targeting, as well as causing serious side effects in non-target tissues. Nanomaterial drug delivery systems (NDDS) have recently shown great promise in optimizing drug distribution, solubility through biocompatible coatings, enhancing bioavailability via PEGylation and reducing side effects. These formulations can enhance a drug's pharmacokinetics by modifying its properties, improve its ability to cross barriers, and boost bioavailability. In addition, NDDS can enable targeted delivery, increase local drug concentrations, improve efficacy, and reduce side effects, as well as protecting active drug molecules from immune recognition and protease degradation. The clinical use of these systems for treating IBD, however, requires further research. This review summarizes the classification of NDDS for IBD, and concludes that, despite ongoing challenges, NDDS may represent an effective treatment approach for IBD. In summary, NDDS enhance the targeted delivery of therapeutic agents to specific cells or tissues, thereby improving drug bioavailability and therapeutic efficacy. These systems effectively surmount biological barriers, facilitating efficient drug delivery to targeted sites, which is crucial for attaining optimal therapeutic outcomes. This review contributes to a deeper understanding of how the physicochemical properties of NDDS influence pharmacological behavior in vivo and can expedite their clinical translation.

Neutrophil-macrophage hybrid membrane-coated prussian blue nanozyme for ulcerative colitis treatment and mechanistic insights

BACKGROUND

Ulcerative colitis (UC) is a chronic and recurrent digestive tract disease that can lead to significant morbidity and mortality. The pathogenesis of UC is intricately associated with the presence of reactive oxygen species (ROS). Prussian blue (PB), an inorganic nanozyme with potent antioxidant properties, has been extensively applied in the treatment of various inflammatory conditions and tumors. However, despite the explicit antioxidant properties, the underlying molecular mechanism of PB nanozyme in the treatment of UC remains poorly understood. Furthermore, there is a deficiency in antioxidants that possess specific targeting capabilities towards UC lesions. The present study pioneered the fabrication of neutrophil (N)-macrophage (M) hybrid membrane-coated PB (NM-PB) nanozyme for the treatment of UC and investigated its underlying molecular mechanism.

RESULTS

We have successfully constructed PB, N-PB, M-PB, and NM-PB nanozymes. In both the colitis cell model and UC mouse model, compared with PB, N-PB, and M-PB nanozymes, NM-PB nanozymes exhibited remarkable targeting capabilities, significantly enhancing the localization and uptake of PB nanozymes at the lesion site. NM-PB nanozymes significantly reduced levels of ROS (•OH, •OOH, and H2O2) and decreased the production of proinflammatory cytokines (TNF-α, IL-6, IL-1β). Meanwhile, these nanozymes regulated the expression of intestinal mucosal barrier-related proteins (ZO-1, E-cadherin, and Occludin) and apoptosis-related proteins (Bcl2, Bax). Furthermore, NM-PB nanozymes facilitated the polarization of proinflammatory M1-phenotype macrophage towards an anti-inflammatory M2-phenotype. The mechanistic studies demonstrated that NM-PB nanozymes mitigated the progression of UC by inhibiting the pathway of cytokine-cytokine receptor interaction.

CONCLUSION

The NM-PB nanozymes provide a promising and innovative alternative for the treatment of UC, offering enhanced targeting and efficacy through their unique design and mechanism of action.

Analysis of nanomedicine applications for inflammatory bowel disease: structural and temporal dynamics, research hotspots, and emerging trends

Background

The application of nanomedicine in inflammatory bowel disease (IBD) has gained significant attention in the recent years. As the field rapidly evolves, analyzing research trends and identifying research hotpots are essential for guiding future advancements, and a comprehensive bibliometric can provide valuable insights.

Methods

The current research focused on publications from 2001 to 2024, and was sourced from the Web of Science Core Collection (WoSCC). CiteSpace and VOSviewer were employed to visualize authors, institutions, countries, co-cited references, and keywords, thereby mapping the intellectual structure and identifying emerging trends in the field.

Results

The analysis covered 1,518 literature across 447 journals, authored by 9,334 researchers from 5,459 institutions and 287 countries/regions. The global publication numbers exhibited an upward trend, particularly in the last decade, with China leading as the top publishing country and the Chinese Academy of Sciences emerging as the foremost institution. Dr. Xiao Bo is the prominent figure in advanced drug delivery systems. This interdisciplinary field, which spans materials science, pharmacy, and medicine, has seen influential publications mainly concentrated on targeted nanoparticles treatment for IBD. Keyword analysis revealed that current research hotspots include drug delivery, immune cell regulation, antioxidant damage, intestinal microbiota homeostasis, and nanovesicles.

Conclusion

This study offers a comprehensive overview of global research landscape, emphasizing the rapid growth and increasing complexity of this field. It identifies key research hotspots and trends, including efforts to enhance the precision, efficacy, and safety of nanomedicine applications. Emerging directions are highlighted as crucial for further progress in this evolving area.

Autocatalytic Ceria Nanoparticle-Embedded Tilapia Collagen Hydrogels as Enhanced Antioxidative and Long-Lasting Dermal Fillers for Photoaged Skin

Excessive reactive oxygen species (ROS) generated by ultraviolet (UV) irradiation significantly contribute to photoaging by increasing the level of matrix metalloproteinases (MMPs), accelerating collagen degradation. Commercial dermal fillers offer temporary wrinkle reduction via volume enhancement. In this study, we propose tilapia-derived collagen hydrogels embedded with ceria nanoparticles (Ce@Col gels) as long-lasting dermal fillers for UVB-induced photoaging. Ceria nanoparticles (CeNPs) significantly enhance the stability of the collagen matrix against enzymatic degradation. These gels exhibit mechanical stability and injectability comparable to those of commercial alternatives. Additionally, CeNPs effectively eliminate ROS to suppress MMP production, curbing both collagen degradation and inflammatory responses. In a UVB-induced photoaging mouse model, the Ce@Col gels significantly reduced the level of oxidative stress in the skin, decreased the number of wrinkles, reduced epidermal thickness, and decreased levels of aging-related biomarkers while increasing the level of collagen deposition. These antiaging effects persisted for seven months post-injection, highlighting Ce@Col gels as a promising approach for prolonged collagen regeneration and sustained anti-inflammatory benefits in photoaged skin.

Cerium Oxide Nanoparticles-Reinforced GelMA Hydrogel Loading Bone Marrow Stem Cells with Osteogenic and Inflammatory Regulatory Capacity for Bone Defect Repair

Effective bone defect repair has been a tough clinical challenge due to the complexity of the bone defect microenvironment. Hydrogels loaded with bone marrow mesenchymal stem cells (BMSCs) have been widely applied for bone regeneration. However, the low survival of BMSCs at the site of transplantation and lack of sufficient osteogenic induction capacity greatly limit their applications. In order to solve this puzzle, we fabricated gelatin methacryloyl (GelMA) hydrogels containing BMSCs with cerium oxide (CeO2) nanoparticles via photo-cross-linking to endow the composite hydrogel with osteogenic induction ability and immune induction ability. In vitro results demonstrated that the GelMA-CeO2-BMSC hydrogel presented with good biocompatibility and excellent osteogenic induction ability. In addition, the GelMA-CeO2-BMSC hydrogel could inhibit M1 polarization and promote M2 polarization, providing a good environment for the growth and osteogenic differentiation of BMSCs. Besides, the GelMA-CeO2-BMSC hydrogel was transplanted into critical-sized calvarial defects, and the results further confirmed its excellent bone regeneration capacity. In conclusion, the composite hydrogel provides a perspective for bone repair due to the remarkable potential for application in bone regeneration.

Fractional extraction phenolics from C. oleifera seed kernels exhibited anti-inflammatory effect via PI3K/Akt/NF-κB signaling pathway under Caco-2/RAW264.7 co-culture cell model

Camellia oleifera Abel (C. oleifera) is a multifunctional oilseed, which is rich in many biological active substances with health-promoting properties, especially polyphenols. Previous research revealed that camellia oil phenolics exhibited anti-inflammatory effect, which originated from seed. Thus, we aimed to explore the components of camellia seed phenolics and its potential mechanism of anti-inflammation. Initially, fractional extraction was processed to prepare the phenolics from camellia seed kernels, and we compare four different fractions of phenolics under the LPS-induced Caco-2/RAW264.7 coculturing model. Results showed that free phenolics (FP) had best effect on alleviating pro-inflammatory cytokines (IL-1β, IL-6, IL-8 and TNF-α) compared to esterified-bound phenolics (EP), glycosylated-bound phenolics (GP) and insoluble-bound phenolics (IP). Furthermore, FP reduced inflammation by suppressing the PI3K/Akt/NF-κB signaling pathway and effectively inhibited LPS-induced intestinal permeability increase, tight junction related proteins loss (ZO-1, claudin-1). Same results obtained, as the transepithelial electrical resistance (TEER) and alkaline phosphatase (AKP) activity of high-dose FP treated group was high than model group. Finally, molecular docking was used for evaluating the anti-inflammatory effect for phenolic monomer. KGRG (kaempferol -3-O-(2-O-glucopyranosyl-6-O-rhamnopyranosyl)-glucopyranoside), KXR (kaempferol 3-O-(2''-xylopyranosyl)-rutinoside) and leucoside (kaempferol 3-O-sambubioside) show lower binding energy docking with NF-κB, PI3K and Akt protein, indicating better interactions, which might be effective constituents against inflammation. Subsequently, five major polyphenols were obtained to validate the docking results, especially, indicating the best anti-inflammatory activities of KGRG. Overall, this research sheds insights on the therapy of phenolics from C. oleifera seed towards LPS-induced intestinal inflammation model in vitro and its related mechanism.

Advances in carbohydrate-based nanoparticles for targeted therapy of inflammatory bowel diseases: A review

The incidence of inflammatory bowel disease (IBD), a chronic gastrointestinal disorder, is rapidly increasing worldwide. Unfortunately, the current therapies for IBD are often hindered by premature drug release and undesirable side effects. With the advancement of nanotechnology, the innovative targeted nanotherapeutics are explored to ensure the accurate delivery of drugs to specific sites in the colon, thereby reducing side effects and improving the efficacy of oral administration. The emphasis of this review is to summarize the potential pathogenesis of IBD and highlight recent breakthroughs in carbohydrate-based nanoparticles for IBD treatment, including their construction, release mechanism, potential targeting ability, and their therapeutic efficacy. Specifically, we summarize the latest knowledge regarding environmental-responsive nano-systems and active targeted nanoparticles. The environmental-responsive drug delivery systems crafted with carbohydrates or other biological macromolecules like chitosan and sodium alginate, exhibit a remarkable capacity to enhance the accumulation of therapeutic drugs in the inflamed regions of the digestive tract. Active targeting strategies improve the specificity and accuracy of oral drug delivery to the colon by modifying carbohydrates such as hyaluronic acid and mannose onto nanocarriers. Finally, we discuss the challenges and provide insight into the future perspectives of colon-targeted delivery systems for IBD treatment.

H2O2 Self-Supplying CaO2 Nanoplatform Induces Ca2+ Overload Combined with Chemodynamic Therapy to Enhance Cancer Immunotherapy

Integrating chemodynamic therapy (CDT) with Ca2+ overload offers a potent strategy for enhancing cancer immunotherapy. However, the effectiveness of this approach is significantly constrained by the scarce availability of H2O2 in solid tumors. Here, we engineered a nanoplatform based on CaO2 nanoparticles (NPs) capable of encapsulating curcumin (CUR) and self-supplying H2O2 for synergistic CDT-augmented antitumor immunotherapy (CaO2@CUR@ZIF-Cu, denoted as CCZC). In the acidic tumor microenvironment, CCZC disintegrated to release CUR and copper(II) ions (Cu2+), revealing the core CaO2 NPs. CDT was amplified by escalating hydroxyl radical (•OH) production through a Fenton-like reaction mediated by H2O2 from the hydrolysis of CaO2 NPs. Ca2+ sourced from CaO2 NPs and CUR, an initiator of Ca2+ overload, induced Ca2+ overload in tumor cells, thereby promoting apoptosis. Subsequently, apoptotic tumor cells released tumor-associated antigens and pro-inflammatory cytokines, triggering adaptive immune responses and enhancing antitumor immunotherapy effects. In vivo experiments demonstrated that the intratumoral administration of CCZC displayed significant inhibitory effects, with an inhibition rate of up to 78% on B16-OVA-tumor-bearing mice compared to untreated. Moreover, an elevated proportion of mature dendritic cells were observed in the tumor-draining lymph nodes, along with an increase in cytotoxic T lymphocytes in the spleen. These findings suggest that our engineered nanoplatform effectively curtailed tumor growth via enhanced cancer immunotherapy by synergizing Ca2+ overload and CDT, proposing a novel strategy for synergistic cancer treatment.

Co-Delivery of Renal Clearable Cerium Complex and Synergistic Antioxidant Iron Complex for Treating Sepsis

The mononuclear phagocytic system clears the circulating inorganic nanomaterials from the bloodstream, which raises concerns about the chronic toxicity of the accumulated metal species. A better understanding of the behavior of each metal after systemic injection is thus required for clinical translations. This study investigates the significance of the metal-ligand interaction on the accumulation of cerium and demonstrates that only the form in which cerium is coordinated to a multidentate chelator with a strong binding affinity does not accumulate in major organs. Specifically, cerium complexed with diethylenetriamine pentaacetic acid (DTPA) forms renally excretable nanoparticles in vivo to circumvent the leaching of cerium ions, whereas weakly coordinated cerium-based nanomaterials produce insoluble precipitates upon encountering physiological phosphate anions. Ceria-based renally clearable nanoparticles (CRNs) derived from cerium-DTPA are utilized as the antioxidant pair with iron-DTPA, in which their combination leverages the Fenton reaction to synergistically scavenge hydrogen peroxide. This reduces the gene expression of pro-inflammatory factors in the macrophages activated with lipopolysaccharide as well as improves the survival rate of septic mice by alleviating the systemic inflammatory response and its downstream tissue injury in the liver, spleen, and kidneys. This study demonstrates that CRNs combined with iron-DTPA can be utilized as nonaccumulative nanomedicines for treating systemic inflammation, thereby overcoming the limitations of conventional ceria nanoparticle-based treatments.

Targeted no-releasing L-arginine-induced hesperetin self-assembled nanoparticles for ulcerative colitis intervention

Overproduction of reactive oxygen species (ROS) plays a crucial role in initiating and advancing ulcerative colitis (UC), and the persistent cycle between ROS and inflammation accelerates disease development. Therefore, developing strategies that can effectively scavenge ROS and provide targeted intervention are crucial for the management of UC. In this study, we synthesized natural carrier-free nanoparticles (HST-Arg NPs) using the Mannich reaction and π-π stacking for the intervention of UC. HST-Arg NPs are an oral formulation that exhibit good antioxidant capabilities and gastrointestinal stability. Benefiting from the negatively charged characteristics, HST-Arg NPs can specifically accumulate in positively charged inflamed regions of the colon. Furthermore, in the oxidative microenvironment of colonic inflammation, HST-Arg NPs respond to ROS by releasing nitric oxide (NO). In mice model of UC induced by dextran sulfate sodium (DSS), HST-Arg NPs significantly mitigated colonic injury by modulating oxidative stress, lowering pro-inflammatory cytokines, and repairing intestinal barrier integrity. In summary, this convenient and targeted oral nanoparticle can effectively scavenge ROS at the site of inflammation and achieve gas intervention, offering robust theoretical support for the development of subsequent oral formulations in related inflammatory interventions. STATEMENT OF SIGNIFICANCE: Nanotechnology has been extensively explored in the biomedical field, but the application of natural carrier-free nanotechnology in this area remains relatively rare. In this study, we developed a natural nanoparticle system based on hesperetin (HST), L-arginine (L-Arg), and vanillin (VA) to scavenge ROS and alleviate inflammation. In the context of ulcerative colitis (UC), the synthesized nanoparticles exhibited excellent intervention effects, effectively protecting the colon from damage. Consequently, these nanoparticles provide a promising and precise nutritional intervention strategy by addressing both oxidative stress and inflammatory pathways simultaneously, demonstrating significant potential for application.

Florfenicol core-shell composite nanogels as oral administration for efficient treatment of bacterial enteritis

To reduce the bitterness of florfenicol, avoid its degradation by gastric acid, and enhance its antibacterial activity against Escherichia coli by targeting and slowly releasing drugs at the site of intestinal infection, with pectin as an anion carrier and chitosan oligosaccharides (COS) as a cationic carrier, florfenicol-loaded COS@pectin core nanogels were self-assembled by electrostatic interaction and then encapsulated in sodium carboxymethylcellulose (CMCNa) shell nanogels through the complexation of CMCNa and Ca2+ to prepare florfenicol core-shell composite nanogels in this study. The florfenicol core-shell composite nanogels were investigated for their formula choice, physicochemical characterization, pH-responsive performances, antibacterial activity, therapeutic efficacy, and in vitro and in vivo biosafety studies. The results indicated that the optimized formula was 0.6 g florfenicol, 0.79 g CMCNa, 0.30 g CaCl2, 0.05 g COS, and 0.10 g pectin, respectively. In addition, the mean particle diameter, polydispersity index, zeta potential, loading capacity, and encapsulation efficiency were 124.0 ± 7.2 nm, -22.9 ± 2.5 mV, 0.42 ± 0.03, 43.4 % ± 3.1 %, and 80.5 % ± 3.4 %, respectively. The appearance, lyophilized mass, resolvability, scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), and fourier transform infrared (FTIR) showed that the florfenicol core-shell composite nanogels were successfully prepared. Florfenicol core-shell composite nanogels had satisfactory stability, rheology, and pH-responsiveness, which were conducive to avoid degradation by gastric acid and achieve targeted and slow release at intestinal infection sites. More importantly, florfenicol core-shell composite nanogels had excellent antibacterial activity against Escherichia coli, a satisfactory therapeutic effect, and good palatability. In vitro and in vivo biosafety studies suggested the great promise of florfenicol core-shell composite nanogels. Therefore, the prepared florfenicol core-shell composite nanogels may be helpful for the treatment of bacterial enteritis as a biocompatible oral administration.

Engineered probiotics with sustained release of interleukin-2 for the treatment of inflammatory bowel disease after oral delivery

Inflammatory bowel disease (IBD) is a kind of auto-immune disease characterized by disrupted intestinal barrier and mucosal epithelium, imbalanced gut microbiome and deregulated immune responses. Therefore, the restoration of immune equilibrium and gut microbiota could potentially serve as a hopeful approach for treating IBD. Herein, the oral probiotic Escherichia coli Nissle 1917 (ECN) was genetically engineered to express secretable interleukin-2 (IL-2), a kind of immunomodulatory agent, for the treatment of IBD. In our design, probiotic itself has the ability to regulate the gut microenvironment and IL-2 at low dose could selectively promote the generation of regulatory T cells to elicit tolerogenic immune responses. To improve the bioavailability of ECN expressing IL-2 (ECN-IL2) in the gastrointestinal tract, enteric coating Eudragit L100-55 was used to coat ECN-IL2, achieving significantly enhanced accumulation of engineered probiotics in the intestine. More importantly, L100-55 coated ECN-IL2 could effectively activated Treg cells to regulate innate immune responses and gut microbiota, thereby relieve inflammation and repair the colon epithelial barrier in dextran sodium sulfate (DSS) induced IBD. Therefore, genetically and chemically modified probiotics with excellent biocompatibility and efficiency in regulating intestinal microflora and intestinal inflammation show great potential for IBD treatment in the future.

Nanotechnology for Targeted Inflammatory Bowel Disease Therapy: Challenges and Opportunities

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

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

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

Oral enzyme-responsive nanoprobes for targeted theranostics of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is a progressive and debilitating inflammatory disease of the gastrointestinal tract (GIT). Despite recent advances, precise treatment and noninvasive monitoring remain challenging.

METHODS

Herein, we developed orally-administered, colitis-targeting and hyaluronic acid (HA)-modified, core-shell curcumin (Cur)- and cerium oxide (CeO2)-loaded nanoprobes (Cur@PC-HA/CeO2 NPs) for computed tomography (CT) imaging-guided treatment and monitoring of IBD in living mice.

RESULTS

Following oral administration, high-molecular-weight HA maintains integrity with little absorption in the upper GIT, and then actively accumulates at local colitis sites owing to its colitis-targeting ability, leading to specific CT enhancement lasting for 24 h. The retained NPs are further degraded by hyaluronidase in the colon to release Cur and CeO2, thereby exerting anti-inflammatory and antioxidant effects. Combined with the ability of NPs to regulate intestinal flora, the oral NPs result in substantial relief in symptoms. Following multiple treatments, the gradually decreasing range of the colon with high CT attenuation correlates with the change in the clinical biomarkers, indicating the feasibility of treatment response and remission.

CONCLUSION

This study provides a proof-of-concept for the design of a novel theranostic integration strategy for concomitant IBD treatment and the real-time monitoring of treatment responses.

Design strategies, advances and future perspectives of colon-targeted delivery systems for the treatment of inflammatory bowel disease

Inflammatory bowel diseases (IBD) significantly contribute to high mortality globally and negatively affect patients' qualifications of life. The gastrointestinal tract has unique anatomical characteristics and physiological environment limitations. Moreover, certain natural or synthetic anti-inflammatory drugs are associated with poor targeting, low drug accumulation at the lesion site, and other side effects, hindering them from exerting their therapeutic effects. Colon-targeted drug delivery systems represent attractive alternatives as novel carriers for IBD treatment. This review mainly discusses the treatment status of IBD, obstacles to drug delivery, design strategies of colon-targeted delivery systems, and perspectives on the existing complementary therapies. Moreover, based on recent reports, we summarized the therapeutic mechanism of colon-targeted drug delivery. Finally, we addressed the challenges and future directions to facilitate the exploitation of advanced nanomedicine for IBD therapy.

Single-atom nanozymes shines diagnostics of gastrointestinal diseases

Various clinical symptoms of digestive system, such as infectious, inflammatory, and malignant disorders, have a profound impact on the quality of life and overall health of patients. Therefore, the chase for more potent medicines is both highly significant and urgent. Nanozymes, a novel class of nanomaterials, amalgamate the biological properties of nanomaterials with the catalytic activity of enzymes, and have been engineered for various biomedical applications, including complex gastrointestinal diseases (GI). Particularly, because of their distinctive metal coordination structure and ability to maximize atom use efficiency, single-atom nanozymes (SAzymes) with atomically scattered metal centers are becoming a more viable substitute for natural enzymes. Traditional nanozyme design strategies are no longer able to meet the current requirements for efficient and diverse SAzymes design due to the diversification and complexity of preparation processes. As a result, this review emphasizes the design concept and the synthesis strategy of SAzymes, and corresponding bioenzyme-like activities, such as superoxide dismutase (SOD), peroxidase (POD), oxidase (OXD), catalase (CAT), and glutathione peroxidase (GPx). Then the various application of SAzymes in GI illnesses are summarized, which should encourage further research into nanozymes to achieve better application characteristics.

Polyphenolic Nanoparticle-Modified Probiotics for Microenvironment Remodeling and Targeted Therapy of Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) refer to multifaceted disorders in the intestinal microenvironment and microbiota homeostasis. In view of the broad bioactivity and high compatibility of polyphenols, there is considerable interest in developing a polyphenol-based collaborative platform to remodel the IBD microenvironment and regulate microbiota. Here, we demonstrated the coordination assembly of nanostructured polyphenols to modify probiotics and simultaneously deliver drugs for IBD treatment. Inspired by the distinctive structure of tannic acid (TA), we fabricated nanostructured pBDT-TA by using a self-polymerizable aromatic dithiol (BDT) and TA, which exhibited excellent antioxidant and anti-inflammatory capability in vitro. We thus coated pBDT-TA and sodium alginate (SA) to the surface of Escherichia coli Nissle 1917 layer by layer to construct the collaborative platform EcN@SA-pBDT-TA. The modified probiotics showed improved resistance to oxidative and inflammatory stress, which resulted in superior colon accumulation and retention in IBD model mice. Further, EcN@SA-pBDT-TA could alleviate dextran sulfate sodium (DSS)-induced colitis by controlling the inflammatory response, repairing intestinal barriers, and modulating gut microbiota. Importantly, EcN@SA-pBDT-TA-mediated IBD drug delivery could achieve an improved therapeutic effect in DSS model mice. Given the availability and functionality of polyphenol and prebiotics, we expected that nanostructured polyphenol-modified probiotics provided a solution to develop a collaborative platform for IBD treatment.

Amorphous silica nanoparticles and the human gut microbiota: a relationship with multiple implications

Amorphous silica nanoparticles (ASNP) are among the nanomaterials that are produced in large quantities. ASNP have been present for a long time in several fast-moving consumer products, several of which imply exposure of the gastrointestinal tract, such as toothpastes, food additives, drug excipients, and carriers. Consolidated use and experimental evidence have consistently pointed to the very low acute toxicity and limited absorption of ASNP. However, slow absorption implies prolonged exposure of the intestinal epithelium to ASNP, with documented effects on intestinal permeability and immune gut homeostasis. These effects could explain the hepatic toxicity observed after oral administration of ASNP in animals. More recently, the role of microbiota in these and other ASNP effects has attracted increasing interest in parallel with the recognition of the role of microbiota in a variety of conditions. Although evidence for nanomaterial effects on microbiota is particularly abundant for materials endowed with bactericidal activities, a growing body of recent experimental data indicates that ASNPs also modify microbiota. The implications of these effects are recounted in this contribution, along with a discussion of the more important open issues and recommendations for future research.