An olsalazine nanoneedle-embedded inulin hydrogel reshapes intestinal homeostasis in inflammatory bowel disease

Incorporating zinc coordination driven nanozyme into chitosan and hyaluronic acid based nanoplatform for scavenging H2S/ROS in managing inflammatory bowel disease

Inflammatory bowel disease (IBD) causes damage to patients, and therapy remains a crucial challenge owing to the presence of excessive reactive oxygen species (ROS) and hydrogen sulfide (H2S) in colonic inflammatory circulation. Herein, we report a shikonin (SK) and zinc (Zn) driven coordination nanozyme (SK-Zn, S-Z), which effectively scavenged ROS and H2S. Furthermore, a pH responsive targeted polymer nanoplatform (S-Z@ChF), consisting of S-Z, chitosan, hyaluronic acid and poly ferulic acid, was developed for the oral treatment of colitis. In vivo experiments revealed that the nanoplatform could target colonic inflammatory lesions, relieve inflammatory index and restore the colonic mechanical barrier. The transcriptomics and pharmacodynamic mechanism analysis revealed that S-Z@ChF scavenged ROS, inhibited nuclear factor kappa-B (NF-κB) and pyruvate kinase isozyme type M2 (PKM2) and signal transducer and activator of transcription 3 (STAT3) pathways, balancing the level of macrophage polarization and pro-inflammatory enzyme. Additionally, S-Z@ChF reliably regulated the gut microbiota during H2S scavenging. In conclusion, S-Z@ChF, which provides multiple anti-inflammatory pathways and microenvironment reprogramming support for blocking inflammatory circulation, was found to be biologically safe, with significant potential for clinical application in IBD.

Copper-luteolin nanocomplexes for Mediating multifaceted regulation of oxidative stress, intestinal barrier, and gut microbiota in inflammatory bowel disease

Oxidative stress, dysbiosis, and immune dysregulation have been confirmed to play pivotal roles in the complex pathogenesis of inflammatory bowel disease (IBD). Herein, we design copper ion-luteolin nanocomplexes (CuL NCs) through a metal-polyphenol coordination strategy, which plays a multifaceted role in the amelioration of IBD. The fabricated CuL NCs function as therapeutic agents with exceptional antioxidant and anti-inflammatory capabilities because of their great stability and capacity to scavenge reactive oxygen species (ROS). It can effectively modulate the inflammatory microenvironment including facilitating the efficient reduction of pro-inflammatory cytokine levels, protecting intestinal epithelial cells, promoting mucosal barrier repair and regulating intestinal microbiota. In addition, CuL NCs have been found to enhance cellular antioxidant and anti-inflammatory capacities by regulating the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) oxidative stress pathway and nuclear factor kappa B (NF-κB) signaling pathway, respectively. Notably, CuL NCs demonstrate significant prophylactic and therapeutic efficacy in mouse models with typical IBD, including ulcerative colitis (UC) and Crohn's disease (CD). This study provides a new approach for building multifaceted therapeutic platforms for natural products to treat IBD.

Adhesive polyelectrolyte coating through UV-triggered polymerization on PLGA particles for enhanced drug delivery to inflammatory intestinal mucosa

Administering medication precisely to the inflamed intestinal sites to treat ulcerative colitis (UC), with minimized side effects, is of urgent need. In UC, the inflammation damaged mucosa contains a large number of amino groups which are positively charged, providing new opportunities for drug delivery system design. Here, we report an oral drug delivery system utilizing the tacrolimus-loaded poly (lactic-co-glycolic acid) (TAC/PLGA) particles with an adhesion coating by in situ UV-triggered polymerization of polyacrylic acid and N-hydroxysuccinimide (PAA-NHS). The negatively charged carboxyl groups effectively interact with the positively charged focal mucosa, and the NHS ester groups form the covalent bonds with the amino groups, thereby synergically enhancing the adhesion of the PLGA particles to the focal mucosa. Our findings reveal that, compared to the naked particles, the PAA-NHS coating increases the adhesion of particles to the inflammatory intestine. In a dextran sulfate sodium-induced acute colitis mouse model, the TAC/PLGA particles with PAA-NHS coating exhibits substantial retention of TAC within the inflammatory intestine, enhancing drug delivery efficiency and therapeutic effects. This approach holds promise for UC management, minimizing systemic side effects and optimizing therapeutic outcomes.

An Oral H2S Responsive Cu5.4O Nanozyme Platform with Strong ROS/H2S Scavenging Capacity for the Treatment of Colitis

Inflammatory bowel disease involves excess reactive oxygen species (ROS) and hydrogen sulfide (H2S) at inflammatory sites. Nanozyme-mediated ROS and H2S scavenging therapy is promising for colitis treatment. Here, we synthesized a multiple ROS scavenging Cu5.4O nanoparticle and first explored its H2S scavenging capacity. Chitosan oligosaccharide modified with alpha-lipoic acid was coated on the nanoparticles to further enhance the H2S scavenging capacity. Furthermore, calcium alginate was coated on the surface to develop an oral nanoplatform (Cu5.4O@SAG) possessing dual-pH/H2S-responsive release characteristics. Importantly, Cu5.4O@SAG exhibited enrichment at the colonic inflammation site and relieved the inflammatory index, containing the recovery of colon length, spleen index, liver index, and body weight, as well as inflammatory cell infiltration. In vivo and in vitro experiments revealed the dual ROS and H2S scavenging capacities of the nanoplatform. Additionally, Cu5.4O@SAG regulated tight junctions, mucus layers, and gut microbiota, which was accompanied by the downregulation of inflammatory cytokines. Notably, Cu5.4O@SAG also had excellent biocompatibility. In conclusion, this oral multiple-scavenging nanozyme platform provides a new and safe paradigm for the development of nanozymes for colitis treatment.

Negatively Charged Thermosensitive Hydrogel Loaded with Pectin Microspheres to Recover the Mucosal Barrier for Ulcerative Colitis Therapy

Ulcerative colitis (UC), a chronic inflammatory bowel disease, poses a heightened colorectal cancer risk due to persistent mucosal inflammation and barrier dysfunction. In this article, a negatively charged thermosensitive hydrogel loaded with pectin microspheres was used as the enema for UC treatment. Succinic acid was immobilized on poly(ε-caprolactone-co-glycolide)-poly(ethylene glycol)-poly(ε-caprolactone-co-glycolide) (PCLGA-PEG-PCLGA) triblock copolymers to preferentially coat on cationic-inflamed sites via electrostatic interaction for reconstructing the mucosal barrier. Anti-inflammation drug 5-aminosalicylic acid (5-ASA) and curcumin-loaded pectin microspheres (Pec@Cur) were dispersed in the hydrogel for the inflammatory treatment of UC. The thermally sensitive hydrogels were rectally injected into UC model mice. The hydrogel effectively adhered to ulcers and prolonged colon retention, enabling sustained drug release and remarkably relieving the symptoms of colitis. The negatively charged hydrogel exhibited excellent significance in the UC treatment.

Functional Ginger-Derived Extracellular Vesicles-Coated ZIF-8 Containing TNF-α siRNA for Ulcerative Colitis Therapy by Modulating Gut Microbiota

Tumor necrosis factor-α (TNF-α) plays a causal role in the pathogenesis of ulcerative colitis (UC), and anti-TNF-α siRNA shows great promise in UC therapy. However, delivering siRNA with site-targeted stability and therapeutic efficacy is still challenging due to the complex and dynamic intestinal microenvironment. Here, based on the functional plant-derived ginger extracellular vesicles (EVs) and porous ZIF-8 nanoparticles, we propose a novel TNF-α siRNA delivery strategy (EVs@ZIF-8@siRNA) for UC targeted therapy. Ginger EVs show strong colon and macrophage targeting, as well as robust resistance to acidic degradation in the stomach. Moreover, 6-shogaol in ginger-derived EVs displays anti-inflammatory effects, which enhance the treatment efficiency by cooperation with TNF-α siRNA. In vitro experiments reveal that ZIF-8 nanoparticles have high TNF-α siRNA loading capacity and promote siRNA escape from cellular lysosomes. In vivo experiments show that the TNF-α level is reduced more significantly in colonic tissue than other nontargeted inflammation related factors, showing a good targeting of this composite nanoparticle. Furthermore, gut microbiota sequencing results demonstrate that the nanoparticles can promote intestinal barrier repair by regulating the intestinal microbial balance and restoring the intestinal health of UC mice. Therefore, the developed EVs@ZIF-8@siRNA nanoparticles may represent a novel colon-targeted oral drug, providing a promising therapeutic strategy for UC therapy.

Ternary inulin hydrogel with long-term intestinal retention for simultaneously reversing IBD and its fibrotic complication

Excessive accumulation of reactive oxygen and nitrogen species (RONS) and dysbiosis of intestinal microbiota are pivotal symptoms for inflammatory bowel disease (IBD) and its associated complications, such as intestinal fibrosis. This research introduces a probiotic inulin hydrogel loaded with polypyrrole (PPy) nanozymes and antifibrotic drug pirfenidone (PFD) (PPy/PFD@Inulin gel) designed for the concurrent amelioration of IBD and its fibrotic complication. Upon oral administration, the inulin gel matrix could extend the gastrointestinal residence time of PPy nanozymes and PFD, facilitating the efficient reduction of pro-inflammatory cytokine levels and enhancement of the intestinal epithelial barrier repair as well as the suppression of intestinal fibrosis through sustained RONS scavenging, modulation of gut microbiota and attenuation of the TGF-β/Smad signaling pathway to inhibit fibroblast proliferation. Notably, the PPy/PFD@Inulin gel demonstrated significant prophylactic and therapeutic efficacy in acute and chronic colitis as well as intestinal fibrosis induced by dextran sodium sulfate (DSS) in mouse models. Thus, the engineered ternary PPy/PFD@Inulin gel offered a pioneered paradigm for simultaneous reversal of IBD and its associated complications, such as intestinal fibrosis, in a single therapeutic regimen.

Acid-Resistant Nano-antioxidants Based on Epigallocatechin Gallate Alleviate Acute Intestinal and Kidney Inflammation

Epigallocatechin gallate (EGCG)-based nanosystems have garnered significant attention for their ability to alleviate inflammation due to their excellent anti-inflammatory properties and enhanced drug delivery capabilities. However, the degradation of EGCG in strongly acidic environments poses a challenge for potential administration, particularly in oral formulations, where gastric resistance is essential. In this study, we develop a "disintegration and reorganization" strategy to create acid-resistant antioxidant nanoparticles (EGA NPs) based on EGCG and 5-aminosalicylic acid (5-ASA) for mitigating inflammation in colitis and acute kidney injury. At acidic pH, the ester bond in EGCG breaks down, producing two building blocks. These, together with 5-ASA and formaldehyde, form oligomers through a combination of phenol-aldehyde condensation and the Mannich reaction. The resulting oligomers self-assemble into EGA NPs, which exhibit significant stability under both acidic and neutral pH conditions. This stability makes them suitable for oral administration, allowing them to withstand harsh gastric conditions, as well as for intravenous injection. Importantly, these oligomers retain the antioxidant and anti-inflammatory properties of EGCG, effectively scavenging reactive oxygen species and reducing intracellular oxidative stress. Additionally, EGA shows potential as a drug carrier, efficiently loading the anti-inflammatory agent curcumin (Cur) to form Cur@EGA NPs. In vivo studies demonstrate the efficacy of Cur@EGA and EGA in alleviating acute colitis and kidney injury following oral and intravenous administration, respectively. These nanoparticulate formulations exhibit superior inflammation reduction compared to free Cur in vivo. Overall, our findings introduce a novel acid-resistant nanoplatform based on EGCG for the treatment of acute inflammation.

Microcapsules based on biological macromolecules for intestinal health: A review

Intestinal dysfunction is becoming increasingly associated with neurological and endocrine issues, raising concerns about its impact on world health. With the introduction of several breakthrough technologies for detecting and treating intestinal illnesses, significant progress has been made in the previous few years. On the other hand, traditional intrusive diagnostic techniques are expensive and time-consuming. Furthermore, the efficacy of conventional drugs (not capsules) is reduced since they are more likely to degrade before reaching their target. In this context, microcapsules based on different types of biological macromolecules have been used to encapsulate active drugs and sensors to track intestinal ailments and address these issues. Several biomacromolecules/biomaterials (natural protein, alginate, chitosan, cellulose and RNA etc.) are widely used for make microcapsules for intestinal diseases, and can significantly improve the therapeutic effect and reduce adverse reactions. This article systematically summarizes microencapsulated based on biomacromolecules material for intestinal health control and efficacy enhancement. It also discusses the application and mechanism research of microencapsulated biomacromolecules drugs in reducing intestinal inflammation, in addition to covering the preparation techniques of microencapsulated drug delivery systems used for intestinal health. Microcapsule delivery systems' limits and potential applications for intestinal disease diagnosis, treatment, and surveillance were highlighted.

Robust reactive oxygen species modulator hitchhiking yeast microcapsules for colitis alleviation by trilogically intestinal microenvironment renovation

Ulcerative colitis (UC) is characterized by chronic inflammatory processes of the intestinal tract of unknown origin. Current treatments lack understanding on how to effectively alleviate oxidative stress, relieve inflammation, as well as modulate gut microbiota for maintaining intestinal homeostasis synchronously. In this study, a novel drug delivery system based on a metal polyphenol network (MPN) was constructed via metal coordination between epigallocatechin gallate (EGCG) and Fe3+. Curcumin (Cur), an active polyphenolic compound, with distinguished anti-inflammatory activity was assembled and encapsulated into MPN to generate Cur-MPN. The obtained Cur-MPN could serve as a robust reactive oxygen species modulator by efficiently scavenging superoxide radical (O2•-) as well as hydroxyl radical (·OH). By hitchhiking yeast microcapsule (YM), Cur-MPN was then encapsulated into YM to obtain CM@YM. Our findings demonstrated that CM@YM was able to protect Cur-MPN to withstand the harsh gastrointestinal environment and enhance the targeting and retention abilities of the inflamed colon. When administered orally, CM@YM could alleviate DSS-induced colitis with protective and therapeutic effects by scavenging ROS, reducing pro-inflammatory cytokines, and regulating the polarization of macrophages to M1, thus restoring barrier function and maintaining intestinal homeostasis. Importantly, CM@YM also modulated the gut microbiome to a favorable state by improving bacterial diversity and transforming the compositional structure to an anti-inflammatory phenotype as well as increasing the content of short-chain fatty acids (SCFA) (such as acetic acid, propionic acid, and butyric acid). Collectively, with excellent biocompatibility, our findings indicate that synergistically regulating intestinal microenvironment will be a promising approach for UC.

Progress in the Preparation and Application of Inulin-Based Hydrogels

Inulin, a natural polysaccharide, has emerged as a promising precursor for the preparation of hydrogels due to its biocompatibility, biodegradability, and structural versatility. This review provides a comprehensive overview of the recent progress in the preparation, characterization, and diverse applications of inulin-based hydrogels. Different synthesis strategies, including physical methods (thermal induction and non-thermal induction), chemical methods (free-radical polymerization and chemical crosslinking), and enzymatic approaches, are discussed in detail. The unique properties of inulin-based hydrogels, such as stimuli-responsiveness, antibacterial activity, and their potential as fat replacers, are highlighted. Special emphasis is given to their promising applications in drug delivery systems, especially for colon-targeted delivery, due to the selective degradation of inulin via colonic microflora. The ability to incorporate both hydrophilic and hydrophobic drugs further expands their therapeutic potential. In addition, the applications of inulin-based hydrogels in responsive materials, the food industry, wound dressings, and tissue engineering are discussed. While significant progress has been achieved, challenges and prospects in optimizing synthesis, improving mechanical properties, and exploring new functionalities are discussed. Overall, this review highlights the remarkable properties of inulin-based hydrogels as a promising class of biomaterials with immense potential in the biomedical, pharmaceutical, and materials science fields.