Inflammation-specific targeted carriers for local drug delivery to inflammatory bowel disease

Zein: Potential biopolymer in inflammatory bowel diseases

Effectively managing inflammatory bowel disease (IBD) poses difficulties due to its persistent nature and unpredictable episodes of exacerbation. There is encouraging evidence that personalized medication delivery systems can improve therapy efficacy while reducing the negative effects of standard medicines. Zein, a protein produced from corn, has garnered interest as a possible means of delivering drugs for the treatment of IBD. This review delves into Zein-based drug delivery systems, showcasing its biodegradability, controlled release capabilities, and biocompatibility. Studies have shown that Zein-based nanoparticles, microcarriers, and core-shell microparticles have the capacity to increase medication stability, enhance targeting in the intestines, and decrease toxicity in animal models of IBD. The review highlights the promise of Zein in personalized therapy for IBD and urges more study to enhance its clinical use.

Liver-Targeted Nanoparticles Loaded with Cannabidiol Based on Redox Response for Effective Alleviation of Acute Liver Injury

The purpose of this work was to construct liver-targeted nanoparticles based on the redox response to effectively deliver cannabidiol (CBD) for the prevention of acute liver injury (ALI). CBD-loaded nanoparticles (CBD NPs) with a particle size of 126.5 ± 1.56 nm were prepared using the polymer DA-PP-LA obtained by grafting pullulan polysaccharide with deoxycholic acid (DA) and α-lipoic acid (α-LA). CBD NPs showed typical redox-response release behavior. Interestingly, CBD NPs exhibited admirable liver targeting ability, significantly accumulated in the liver, and effectively promoted the internalization of CBD in liver cells, thus effectively reducing the H2O2-induced oxidative damage of HepG2 cells and avoiding apoptosis. More importantly, CBD NPs effectively prevented CCl4-induced ALI by protecting liver function, ameliorating oxidative stress levels, inhibiting the production of inflammatory factors, and protecting the liver from histological damage. This study provides a promising strategy for achieving targeted delivery of CBD NPs in the liver, thereby effectively preventing ALI.

Lipid- and polymer-based formulations containing TNF-α inhibitors for the treatment of inflammatory bowel diseases

Monoclonal antibodies inhibiting tumor necrosis factor-alpha (iTNF-α) have revolutionized the therapeutic regimen of inflammatory bowel disease, but their main drawback is the parenteral route of administration they require. An alternative approach lies in the delivery of these molecules to the area involved in the inflammatory process by means of innovative formulations able to promote their localization in affected tissues while also decreasing the number of administrations required. This review describes the advantages deriving from the use of lipid- and polymer-based systems containing iTNF-α, focusing on their physicochemical and technological properties and discussing the preclinical results obtained in vivo using rodent models of colitis.

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.

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.

Dual-Responsive Microsphere Based on Natural Sunflower Pollen for Hemostasis and Repair in Inflammatory Bowel Disease

Noninvasive treatment of inflammatory bowel disease with lower gastrointestinal bleeding is a major clinical challenge. In this study, we designed an orally targeted microsphere based on sunflower pollen microcapsules to localize the site of inflammatory injury and promote hemostasis and tissue repair. Due to the Eudragit and ascorbate palmitate coatings, EL/AP@PS(t+Dex) demonstrates pH- and enzyme-responsive release of loaded drugs and helps to resist the harsh environment of the gastrointestinal tract. Both in vitro and in vivo experiments show the characteristics of inflammation targeting and mucosal adhesion, which reduce the systematic exposure and increase the local drug concentration. In the DSS model, orally administered EL/AP@PS(t+Dex) significantly alleviates hematochezia, inhabits intestinal inflammation, and remarkably promotes the recovery of the intestinal epithelial barrier to reduce the exposure of intestinal microvessels. Furthermore, EL/AP@PS(t+Dex) optimized the composition of intestinal microbiota, which benefits intestinal homeostasis. This finding provides a fundamental solution for the treatment of intestinal bleeding caused by inflammatory bowel disease (IBD).

Intestinal Targeted Nanogel with Broad-Spectrum Autonomous ROS Scavenging Performance for Enhancing the Bioactivity of trans-Resveratrol

Introduction

To improve the bioavailability of trans-resveratrol (trans-Res), it is commonly co-delivered with antioxidant bioactives using a complex synthetic intestinal targeted carrier, however, which makes practical application challenging.

Methods

A nanogel (Ngel), as broad-spectrum autonomous ROS scavenger, was prepared using selenized thiolated sodium alginate (TSA-Se) and crosslinked with calcium lactate (CL) for loading trans-Res to obtain Ngel@Res, which maintained spherical morphology in the upper digestive tract but broke down in the lower digestive tract, resulting in trans-Res release.

Results

Under protection of Ngel, trans-Res showed enhanced stability and broad-spectrum ROS scavenging activity. The synergistic mucoadhesion of Ngel prolonged the retention time of trans-Res in the intestine. Ngel and Ngel@Res increased the lifespan of Caenorhabditis elegans to 26.00 ± 2.17 and 26.00 ± 4.27 days by enhancing the activity of antioxidases, upregulating the expression of daf-16, sod-5 and skn-1, while downregulating the expression of daf-2 and age-1.

Conclusion

This readily available, intestinal targeted selenized alginate-based nanogel effectively improves the bioactivity of trans-Res.

Challenges in IBD Research 2024: Novel Technologies

Novel technology is one of the five focus areas of the Challenges in Inflammatory Bowel Disease (IBD) Research 2024 document. Building off the Challenges in IBD Research 2019 document, the Foundation aims to provide a comprehensive overview of current gaps in IBD research and deliver actionable approaches to address them with a focus on how these gaps can lead to advancements in interception, remission, and restoration for these diseases. The document is the result of a multidisciplinary collaboration from scientists, clinicians, patients, and funders and represents a valuable resource for patient-centric research prioritization. Specifically, the Novel Technologies section focuses on addressing key research gaps to enable interception and improve remission rates in IBD. This includes testing predictions of disease onset and progression, developing novel technologies tailored to specific phenotypes, and facilitating collaborative translation of science into diagnostics, devices, and therapeutics. Proposed priority actions outlined in the document include real-time measurement of biological changes preceding disease onset, more effective quantification of fibrosis, exploration of technologies for local treatment of fistulas, and the development of drug delivery platforms for precise, location-restricted therapies. Additionally, there is a strong emphasis on fostering collaboration between various stakeholders to accelerate progress in IBD research and treatment. Addressing these research gaps necessitates the exploration and implementation of bio-engineered novel technologies spanning a spectrum from materials to systems. By harnessing innovative ideas and technologies, there's a collective effort to enhance patient care and outcomes for individuals affected by IBD.

Selective Uptake Into Inflamed Human Intestinal Tissue and Immune Cell Targeting by Wormlike Polymer Micelles

Inflammatory bowel disease (IBD) has become a globally prevalent chronic disease with no causal therapeutic options. Targeted drug delivery systems with selectivity for inflamed areas in the gastrointestinal tract promise to reduce severe drug-related side effects. By creating three distinct nanostructures (vesicles, spherical, and wormlike micelles) from the same amphiphilic block copolymer poly(butyl acrylate)-block-poly(ethylene oxide) (PBA-b-PEO), the effect of nanoparticle shape on human mucosal penetration is systematically identified. An Ussing chamber technique is established to perform the ex vivo experiments on human colonic biopsies, demonstrating that the shape of polymeric nanostructures represents a rarely addressed key to tissue selectivity required for efficient IBD treatment. Wormlike micelles specifically enter inflamed mucosa from patients with IBD, but no significant uptake is observed in healthy tissue. Spheres (≈25 nm) and vesicles (≈120 nm) enter either both normal and inflamed tissue types or do not penetrate any tissue. According to quantitative image analysis, the wormlike nanoparticles localize mainly within immune cells, facilitating specific targeting, which is crucial for further increasing the efficacy of IBD treatment. These findings therefore demonstrate the untapped potential of wormlike nanoparticles not only to selectively target the inflamed human mucosa, but also to target key pro-inflammatory cells.

Responsively Degradable Nanoarmor-Assisted Super Resistance and Stable Colonization of Probiotics for Enhanced Inflammation-Targeted Delivery

Manipulation of the gut microbiota using oral microecological preparations has shown great promise in treating various inflammatory disorders. However, delivering these preparations while maintaining their disease-site specificity, stability, and therapeutic efficacy is highly challenging due to the dynamic changes associated with pathological microenvironments in the gastrointestinal tract. Herein, a superior armored probiotic with an inflammation-targeting capacity is developed to enhance the efficacy and timely action of bacterial therapy against inflammatory bowel disease (IBD). The coating strategy exhibits suitability for diverse probiotic strains and has negligible influence on bacterial viability. This study demonstrates that these armored probiotics have ultraresistance to extreme intraluminal conditions and stable mucoadhesive capacity. Notably, the HA-functionalized nanoarmor equips the probiotics with inflamed-site targetability through multiple interactions, thus enhancing their efficacy in IBD therapy. Moreover, timely "awakening" of ingested probiotics through the responsive transferrin-directed degradation of the nanoarmor at the site of inflammation is highly beneficial for bacterial therapy, which requires the bacterial cells to be fully functional. Given its easy preparation and favorable biocompatibility, the developed single-cell coating approach provides an effective strategy for the advanced delivery of probiotics for biomedical applications at the cellular level.

Bioinspired and biomimetic strategies for inflammatory bowel disease therapy

Inflammatory bowel disease (IBD) is an idiopathic chronic inflammatory bowel disease with high morbidity and an increased risk of cancer or death, resulting in a heavy societal medical burden. While current treatment modalities have been successful in achieving long-term remission and reducing the risk of complications, IBD remains incurable. Nanomedicine has the potential to address the high toxic side effects and low efficacy in IBD treatment. However, synthesized nanomedicines typically exhibit some degree of immune rejection, off-target effects, and a poor ability to cross biological barriers, limiting the development of clinical applications. The emergence of bionic materials and bionic technologies has reshaped the landscape in novel pharmaceutical fields. Biomimetic drug-delivery systems can effectively improve biocompatibility and reduce immunogenicity. Some bioinspired strategies can mimic specific components, targets or immune mechanisms in pathological processes to produce targeting effects for precise disease control. This article highlights recent research on bioinspired and biomimetic strategies for the treatment of IBD and discusses the challenges and future directions in the field to advance the treatment of IBD.

Growth Factors-Loaded Temperature-Sensitive Hydrogel as Biomimetic Mucus Attenuated Murine Ulcerative Colitis via Repairing the Mucosal Barriers

The pathogenesis of ulcerative colitis (UC) is associated with the shedding of the gut mucus. Herein, inspired by the biological functions of mucus, growth factors-loaded in situ hydrogel (PHE-EK) was designed for UC treatment by integrating dihydrocaffeic acid-modified poloxamer as a thermosensitive material with hyaluronic acid (colitis-specific adhesive), epigallocatechin-3-gallate (antibacterial agent), and bioactive factors (KPV tripeptide and epidermal growth factor). PHE-EK presented good thermosensitive properties, as a flowable liquid at room temperature and gelled within 10 s when exposed to body temperature. PHE-EK hydrogel presented good mechanical strength with a strain of 77.8%. Moreover, PHE-EK hydrogel displayed antibacterial activity against Escherichia coli. Importantly, in vitro and in vivo adhesive tests showed that the PHE-EK hydrogel could specifically adhere to the inflamed colon via electrostatic interaction. When PHE-EK as a biomimetic mucus was rectally administrated to colitis rats, it effectively hindered the body weight loss, reduced the disease activity index and improved the colonic shorting. Moreover, the expression of pro-inflammatory cytokines (e.g., IL-1β, IL-6, and TNF-α) at the laminae propria or epitheliums of the colon for colitis rats was substantially inhibited by PHE-EK. Besides, the colonic epitheliums were well rearranged, and the tight junction proteins (Zonula-1 and Claudin-5) between them were greatly upregulated after PHE-EK treatment. Collectively, PHE-EK might be a promising therapy for UC.

Advancements in hydrogel-based drug delivery systems for the treatment of inflammatory bowel disease: a review

Inflammatory bowel disease (IBD) is a chronic disorder that affects millions of individuals worldwide. However, current drug therapies for IBD are plagued by significant side effects, low efficacy, and poor patient compliance. Consequently, there is an urgent need for novel therapeutic approaches to alleviate IBD. Hydrogels, three-dimensional networks of hydrophilic polymers with the ability to swell and retain water, have emerged as promising materials for drug delivery in the treatment of IBD due to their biocompatibility, tunability, and responsiveness to various stimuli. In this review, we summarize recent advancements in hydrogel-based drug delivery systems for the treatment of IBD. We first identify three pathophysiological alterations that need to be addressed in the current treatment of IBD: damage to the intestinal mucosal barrier, dysbiosis of intestinal flora, and activation of inflammatory signaling pathways leading to disequilibrium within the intestines. Subsequently, we discuss in depth the processes required to prepare hydrogel drug delivery systems, from the selection of hydrogel materials, types of drugs to be loaded, methods of drug loading and drug release mechanisms to key points in the preparation of hydrogel drug delivery systems. Additionally, we highlight the progress and impact of the hydrogel-based drug delivery system in IBD treatment through regulation of physical barrier immune responses, promotion of mucosal repair, and improvement of gut microbiota. In conclusion, we analyze the challenges of hydrogel-based drug delivery systems in clinical applications for IBD treatment, and propose potential solutions from our perspective.

Oral delivery of pH-sensitive nanoparticles loaded Celastrol targeting the inflammatory colons to treat ulcerative colitis

The incidence of ulcerative colitis (UC) is rapidly rising worldwide. Oral drug delivery system is a promising approach for treating UC, but it often fails to accumulate to the inflammatory lesions, thus, it is impressive to develop a colon-targeted oral delivery system for preventing systemic toxicity and maintaining UC therapeutics. Here, a negative-charged PLGA nanoparticle system was designed to encapsulate celastrol (Cel), and then chitosan and mannose were coated on the surface of the nanoparticles (MC@Cel-NPs) to endow these nanoparticles with the mucosal adsorption and macrophage targeting abilities. MC@Cel-NPs demonstrate excellent resist decomposition ability against the strong acidic gastrointestinal environment, and accumulates in the specific inflammatory sites through the affinity of electrostatic reaction. After releasing the payload, MC@Cel-NPs could remarkably alleviate the colon inflammation, which was evidenced by the decrease in pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 in both blood and colon sections, and scavenging reactive oxygen species (ROS) in colon cells, including macrophage, neutrophil, T cell, and B cell. This nanoparticle system provided a new approach for treating UC through a Chinese herbal ingredient-related oral delivery manner.

Porphyra haitanensis polysaccharide-functionalized selenium nanoparticles for effective alleviation of ulcerative colitis

Exacerbated intestinal inflammation, oxidative stress imbalance, and damage to intestinal mucosal barrier are closely related to the pathogenesis and progression of ulcerative colitis (UC). Selenium nanoparticles (Se NPs) have demonstrated promising potential to alleviate UC symptoms, however, their poor solubility and stability leading to aggregation and large precipitates have significantly limit their clinical application. In this study, we aimed to enhance the performance of Se NPs by functionalizing them with Porphyra haitanensis polysaccharide, yielding PHP-Se NPs. As expected, these PHP-Se NPs exhibited reduced particle size (70.51 ± 2.92 nm), enhanced cellular uptake compared to native Se NPs, and preferential accumulation in the colonic tissue, providing targeted UC treatment. In vivo animal experiments revealed that PHP-Se NPs significantly improved weight loss, shortened colon length, and higher disease activity index (DAI) scores in DSS-induced UC mice. Moreover, PHP-Se NPs significantly inhibited the levels of inflammatory factors in colitis tissues and oxidative stress in serum of UC mice, improved histological damage in colitis tissues, and restored the intestinal mucosal barrier. Taken together, our study offers an innovative approach to augment the bioavailability of Se NPs, presenting a promising strategy for the effective prevention and management of UC.

Orally-administered nanomedicine systems targeting colon inflammation for the treatment of inflammatory bowel disease: latest advances

Inflammatory bowel disease (IBD) is a chronic and idiopathic condition that results in inflammation of the gastrointestinal tract, leading to conditions such as ulcerative colitis and Crohn's disease. Commonly used treatments for IBD include anti-inflammatory drugs, immunosuppressants, and antibiotics. Fecal microbiota transplantation is also being explored as a potential treatment method; however, these drugs may lead to systemic side effects. Oral administration is preferred for IBD treatment, but accurately locating the inflamed area in the colon is challenging due to multiple physiological barriers. Nanoparticle drug delivery systems possess unique physicochemical properties that enable precise delivery to the target site for IBD treatment, exploiting the increased permeability and retention effect of inflamed intestines. The first part of this review comprehensively introduces the pathophysiological environment of IBD, covering the gastrointestinal pH, various enzymes in the pathway, transport time, intestinal mucus, intestinal epithelium, intestinal immune cells, and intestinal microbiota. The second part focuses on the latest advances in the mechanism and strategies of targeted delivery using oral nanoparticle drug delivery systems for colitis-related fields. Finally, we present challenges and potential directions for future IBD treatment with the assistance of nanotechnology.

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.

Research Status of Dendrimer Micelles in Tumor Therapy for Drug Delivery

Dendrimers are a family of polymers with highly branched structure, well-defined composition, and extensive functional groups, which have attracted great attention in biomedical applications. Micelles formed by dendrimers are ideal nanocarriers for delivering anticancer agents due to the explicit study of their characteristics of particle size, charge, and biological properties such as toxicity, blood circulation time, biodistribution, and cellular internalization. Here, the classification, preparation, and structure of dendrimer micelles are reviewed, and the specific functional groups modified on the surface of dendrimers for tumor active targeting, stimuli-responsive drug release, reduced toxicity, and prolonged blood circulation time are discussed. In addition, their applications are summarized as various platforms for biomedical applications related to cancer therapy including drug delivery, gene transfection, nano-contrast for imaging, and combined therapy. Other applications such as tissue engineering and biosensor are also involved. Finally, the possible challenges and perspectives of dendrimer micelles for their further applications are discussed.

An Orally-Administered Nanotherapeutics with Carbon Monoxide Supplying for Inflammatory Bowel Disease Therapy by Scavenging Oxidative Stress and Restoring Gut Immune Homeostasis

Traditional drug-based treatments for inflammatory bowel disease (IBD) have significant limitations due to their potential off-target systemic side-effects. Currently, there is a lack of understanding on how to effectively address excessive oxidative stress, dysregulated immune homeostasis, and microbiota dysbiosis within the IBD microenvironment. Herein, we introduce a nanotherapeutic approach, named LBL-CO@MPDA, for IBD treatment. LBL-CO@MPDA is an orally administered formulation that supplies carbon monoxide (CO) for therapeutic purposes. To create the LBL-CO@MPDA nanocomposite, we developed a layer by layer (LBL) self-assembly strategy where we coated chitosan/alginate polyelectrolytes onto the surface of CO prodrug-loaded mesoporous polydopamine nanoparticles (CO@MPDA). Benefiting from the negatively charged surface of the LBL coating, it allows for targeted accumulation of LBL-CO@MPDA specifically onto the positively charged inflamed colon lesions through electrostatic interactions. Furthermore, in the oxidative microenvironment of the inflamed colon, the nanotherapeutic system releases CO in a responsive manner. Interestingly, CO@MPDA ameliorates inflammatory conditions by MPDA-mediated ROS-scavenging and CO-mediated immunomodulation. CO-supplying activates heme oxygenase-1, leading to macrophage M2 polarization via the Notch/Hes1/Stat3 signaling pathway, while suppressing the inflammatory response by down-regulating the p38 MAPK and NF-κB (p50/p65) signaling pathways. In the mice model of dextran sulfate sodium (DSS)-induced IBD, LBL-CO@MPDA effectively reverses the pro-inflammatory microenvironment and restores gut barrier functions through multiple mechanisms, including scavenging oxidative stress, restoring immune homeostasis, and modulating the gut microbiota. Collectively, our findings highlight the promising potential of this innovative nanotherapeutic strategy for the targeted treatment of IBD.

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.

Cell membrane nanomaterials composed of phospholipids and glycoproteins for drug delivery in inflammatory bowel disease: A review

Inflammatory bowel disease (IBD) is a serious chronic intestinal disorder with an increasing global incidence. However, current treatment strategies, such as anti-inflammatory drugs and probiotics, have limitations in terms of safety, stability, and effectiveness. The emergence of targeted nanoparticles has revolutionized IBD treatment by enhancing the biological properties of drugs and promoting efficiency and safety. Unlike synthetic nanoparticles, cell membrane nanomaterials (CMNs) consist primarily of biological macromolecules, including phospholipids, proteins, and sugars. CMNs include red blood cell membranes, macrophage membranes, and leukocyte membranes, which possess abundant glycoprotein receptors and ligands on their surfaces, allowing for the formation of cell-to-cell connections with other biological macromolecules. Consequently, they exhibit superior cell affinity, evade immune responses, and target inflammation effectively, making them ideal material for targeted delivery of IBD therapies. This review explores various CMNs delivery systems for IBD treatment. However, due to the complexity and harsh nature of the intestinal microenvironment, the lack of flexibility or loss of selectivity poses challenges in designing single CMNs delivery strategies. Therefore, we propose a hierarchically programmed delivery modality that combines CMNs with pH, charge, ROS and ligand-modified responsive nanoparticles. This approach significantly improves delivery efficiency and points the way for future research in this area.

Inflammation-responsive drug delivery nanosystems for treatment of bacterial-induced sepsis

Sepsis, a complication of dysregulated host immune systemic response to an infection, is life threatening and causes multiple organ injuries. Sepsis is recognized by WHO as a big contributor to global morbidity and mortality. The heterogeneity in sepsis pathophysiology, antimicrobial resistance threat, the slowdown in the development of antimicrobials, and limitations of conventional dosage forms jeopardize the treatment of sepsis. Drug delivery nanosystems are promising tools to overcome some of these challenges. Among the drug delivery nanosystems, inflammation-responsive nanosystems have attracted considerable interest in sepsis treatment due to their ability to respond to specific stimuli in the sepsis microenvironment to release their payload in a precise, targeted, controlled, and rapid manner compared to non-responsive nanosystems. These nanosystems posit superior therapeutic potential to enhance sepsis treatment. This review critically evaluates the recent advances in the design of drug delivery nanosystems that are inflammation responsive and their potential in enhancing sepsis treatment. The sepsis microenvironment's unique features, such as acidic pH, upregulated receptors, overexpressed enzymes, and enhanced oxidative stress, that form the basis for their design have been adequately discussed. These inflammation-responsive nanosystems have been organized into five classes namely: Receptor-targeted nanosystems, pH-responsive nanosystems, redox-responsive nanosystems, enzyme-responsive nanosystems, and multi-responsive nanosystems. Studies under each class have been thematically grouped and discussed with an emphasis on the polymers used in their design, nanocarriers, key characterization, loaded actives, and key findings on drug release and therapeutic efficacy. Further, this information is concisely summarized into tables and supplemented by inserted figures. Additionally, this review adeptly points out the strengths and limitations of the studies and identifies research avenues that need to be explored. Finally, the challenges and future perspectives on these nanosystems have been thoughtfully highlighted.

pH/enzyme dual sensitive Gegenqinlian pellets coated with Bletilla striata polysaccharide membranes for the treatment of ulcerative colitis

Gegen Qinlian Decoction, derived from Zhang Zhongjing's Treatise on Typhoid Fever, has been widely used in the treatment of various common diseases, frequently-occurring diseases and difficult and complicated diseases, such as ulcerative colitis. In this study, Bletilla striata polysaccharide (BSP) was innovatively used as a film coating material to prepare Gegen Qinlian pellets with dual sensitivity of pH enzyme for the treatment of ulcerative colitis. BSP has the ability to repair the inflamed colon mucosa and can produce synergistic effects, while avoiding the adverse therapeutic effects caused by the early release of drugs from a single pH-sensitive pellets in the small intestine. The prepared pellets have a uniform particle size, good roundness, a particle size range from 0.8 mm to 1.0 mm, and a particle yield is 85.6 %. The results of in vitro release showed that ES-BSP pellets hardly released drugs in the pH range of 1.2-6.8. However, in the colon mimic fluid containing specific enzymes, the drug release was significantly accelerated, demonstrating the sensitivity of the pellets to pH enzymes. In vivo and ex vivo fluorescence imaging of small animals showed that Gegen Qinlian pellets with dual sensitivity of pH enzyme remained longer in the colon compared with pH-sensitive pellets. In vivo pharmacodynamics study showed that the Gegen Qinlian pellets with dual sensitivity of pH enzyme had a better therapeutic effect in the rat model of the ulcerative colon than the commercially available Gegenqinlian pellets in the control group.

Injectable Bioadhesive Hydrogels Scavenging ROS and Restoring Mucosal Barrier for Enhanced Ulcerative Colitis Therapy

Despite the progress in the therapy of ulcerative colitis (UC), long-lasting UC remission can hardly be achieved in the majority of UC patients. The key pathological characteristics of UC include an impaired mucosal barrier and local inflammatory infiltration. Thus, a two-pronged approach aiming at repairing damaged mucosal barrier and scavenging inflammatory mediators simultaneously might hold great potential for long-term remission of UC. A rectal formulation can directly offer preferential and effective drug delivery to inflamed colon. However, regular intestinal peristalsis and frequent diarrhea in UC might cause transient drug retention. Therefore, a bioadhesive hydrogel with strong interaction with intestinal mucosa might be preferable for rectal administration to prolong drug retention. Here, we designed a bioadhesive hydrogel formed by the cross-linking of sulfhydryl chondroitin sulfate and polydopamine (CS-PDA). The presence of PDA would ensure the mucosa-adhesive behavior, and the addition of CS in the hydrogel network was expected to achieve the restoration of the intestinal epithelial barrier. To scavenge the key player (excessive reactive oxygen species, ROS) in inflamed colon, sodium ferulic (SF), a potent ROS inhibitor, was incorporated into the CS-PDA hydrogel. After rectal administration, the SF-loaded CS-PDA hydrogel could adhere to the colonic mucosa to allow prolonged drug retention. Subsequently, sustained SF release could be achieved to persistently scavenge ROS in inflammatory areas. Meanwhile, the presence of CS would promote the restoration of the mucosal barrier. Ultimately, scavenging ROS and restoring the mucosal barrier could be simultaneously achieved via this SF-loaded bioadhesive hydrogel scaffold. Our two-pronged approach might provide new insight for effective UC treatment.

Alginate-based drug carrier systems to target inflammatory bowel disease: A review

Inflammatory bowel disease (IBD) is an inflammatory disorder that affects the gastrointestinal tract. IBD has become an increasingly common condition in both developed and developing nations over the last few decades, owing to a variety of factors like a rising population and diets packed with processed and junk foods. While the root pathophysiology of IBD is unknown, treatments are focused on medications aimed to mitigate symptoms. Alginate (AG), a marine-derived polysaccharide, is extensively studied for its biocompatibility, pH sensitivity, and crosslinking nature. This polymer is thoroughly researched in drug delivery systems for IBD treatment, as it is naturally available, non-toxic, cost effective, and can be easily and safely cross-linked with other polymers to form an interconnected network, which helps in controlling the release of drugs over an extended period. There are various types of drug delivery systems developed from AG to deliver therapeutic agents; among them, nanotechnology-based systems and hydrogels are popular due to their ability to facilitate targeted drug delivery, reduce dosage, and increase the therapeutic efficiency. AG-based carrier systems are not only used for the sustained release of drug, but also used in the delivery of siRNA, interleukins, and stem cells for site directed drug delivery and tissue regenerating ability respectively. This review is focussed on pathogenesis and currently studied medications for IBD, AG-based drug delivery systems and their properties for the alleviation of IBD. Moreover, future challenges are also be discoursed to improve the research of AG in the field of biopharmaceuticals and drug delivery.

Orally Administrated Olsalazine-Loaded Multilayer Pectin/Chitosan/Alginate Composite Microspheres for Ulcerative Colitis Treatment

The pathogenesis of inflammatory bowel diseases (IBDs) including ulcerative colitis (UC) and Crohn's disease is extremely cloudy. Maintaining the level of remission lesions in colitis is the default treatment attitude at present. Epithelial barrier restoration is considered as the same important strategy as colonic targeted drug delivery in UC treatment. In this paper, we developed a multilayer natural polysaccharide microsphere (pectin/chitosan/alginate) with pH and enzyme dual sensitivity to reduce the loss of medication in the upper digestive tract and preferentially adhere to exposed epithelial cells in colonic tissues by electrostatic forces for efficiently targeted UC treatment. Olsalazine as an inflammatory drug was efficiently loaded in the chitosan layer and realized a colonic pH-responsive drug release. Furthermore, the multilayer microspheres exhibited excellent capability in suppressing harmful flora and a bio-adhesion effect to extend the duration of local medicine. In the in vivo anti-colitis study, the downregulated levels of pro-inflammatory factors and the increase of tight junction protein indicated the excellent anti-inflammation effect of the olsalazine-loaded microspheres. In summary, these results showed that the multilayer natural polysaccharide microspheres could be a powerful candidate in the targeted drug delivery system for UC therapy.

Bio-adhesive and ROS-scavenging hydrogel microspheres for targeted ulcerative colitis therapy

Ulcerative colitis (UC) as an important type of inflammatory bowel disease is a chronic disease characterized by intestinal dyshomeostasis. The UC treatment is challenged by the insufficiency of drug delivery and retention. Herein, we fabricated an intrarectal formulation of olsalazine (Olsa)-loaded hydrogel microspheres (LDKT/Olsa) with good bio-adhesiveness and reactive oxygen species (ROS)-scavenging ability to enhance drug retention and therapeutic effect. Low methoxy pectin-dopamine conjugate/konjac glucomannan composite hydrogel microspheres (LDKT) with a size ranging from 10 to 100 μm were prepared by using Zn²⁺ and ROS-sensitive thioketal as crosslinkers. Upon intrarectal administration, the negatively charged and dopamine-functionalized hydrogel microspheres efficiently adhered to cationic surface of inflammatory mucosa, scavenging ROS and releasing Zn²⁺ and Olsa for antibacterial and anti-inflammatory effects. In the dextran sodium sulfate (DSS)-induced mouse UC model, the microspheres significantly reduced the levels of colonic ROS and pro-inflammatory cytokines, improved gut mucosal barrier integrity, and remarkably relieved colitis. Overall, the LDKT microspheres are promising carriers to deliver drugs for UC treatment.

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.

IBD disease-modifying therapies: insights from emerging therapeutics

Inflammatory bowel disease (IBD) pathogenesis is associated with gut mucosal inflammation, epithelial damage, and dysbiosis leading to a dysregulated gut mucosal barrier. However, the extent and underlying mechanisms remain largely unknown. Current treatment regimens have focused mainly on treating IBD symptoms; however, such treatment strategies do not address mucosal epithelial repair, barrier homeostasis, or intestinal dysbiosis. Although attempts have been made to identify new therapeutic modalities to enhance gut barrier functions, these are at an early developmental stage and have not been wholly successful. We review conventional therapies, the possible relevant role of gut barrier-protecting agents, and biomaterial strategies relating to combination therapies that may pave the way towards developing new therapeutic approaches for IBD.

Establishment of a gut-on-a-chip device with controllable oxygen gradients to study the contribution of Bifidobacterium bifidum to inflammatory bowel disease

Supplemental Bifidobacterium has been shown to aid in the prevention, alleviation, and treatment of inflammatory bowel disease (IBD), but the progression and mechanisms are largely unstudied, partly because of a lack of appropriate models. In vitro human gut models must accurately recreate oxygen concentration gradients consistent with those in vivo to mimic gene expression, metabolism, and host-microbiome interactions. A non-equipment-intensive and inexpensive method for constructing the gut-on-a-chip with physiological oxygen concentration gradients remains challenging. Here, we propose a simple strategy using numerical simulations in a dual-channel gut-on-a-chip to guide chip design and achieve controllable oxygen gradients. By varying the size of microchannels, blocking the oxygen penetration of the polydimethylsiloxane layer at a given location, and controlling the flow of hypoxic/aerobic media, this strategy creates steep gradients across the intestinal epithelium. IBD symptoms were induced on the chip by tumor necrosis factor-α and lipopolysaccharide treatment. Bifidobacterium bifidum has been validated to contribute to the stability of the intestinal epithelial barrier, including preventing epithelial barrier disruption and promoting the repair of damaged intestinal epithelial cell monolayers. These effects may be associated with the co-localization of Bifidobacterium bifidum and ZO-1. This simple but robust approach for designing microfluidic devices is applicable to various organs-on-chips in which fluid dynamics and concentration profiles between different media must be considered. With the customized chip, the integration of activated Bifidobacterium bifidum provides an initial step toward developing a multi-factorial IBD platform. The approach could be scaled up for disease modeling, high-throughput drug screening and personalized medicine.

A review on curcumin colon-targeted oral drug delivery systems for the treatment of inflammatory bowel disease

Synthetic drugs and monoclonal antibodies are the typical treatments to combat inflammatory bowel disease (IBD). However, side effects are present when these treatments are used, and their continued application could be restricted by the high relapse rate of the disease. One potential alternative to these treatments is the use of plant-derived products. The use curcumin is one such treatment option that has seen an increase in usage in treating IBD. Curcumin is derived from a rhizome of turmeric (Curcuma longa), and the results of studies on the use of curcumin to treat IBD are promising. These studies suggest that curcumin interacts with cellular targets such as NF-κB, JAKs/STATs, MAPKs, TNF-α, IL-6, PPAR, and TRPV1 and may reduce the progression of IBD. Potentially, curcumin can be used as a therapeutic agent for patients with IBD when it reduces the incidence of clinical relapse. This review discusses the strategies utilized in designing and developing an oral colonic delivery dosage form of curcumin.

Polyester-based long acting injectables: Advancements in molecular dynamics simulation and technological insights

Long-acting injectable (LAI) delivery technologies have enabled the development of several pharmaceutical products that improve patient health by delivering therapeutics from weeks to months. Over the last decade, due to its good biocompatibility, formulation tunability, wide range of degradation rates, and extensive clinical studies, polyester-based LAI technologies including poly(lactic-co-glycolic acid) (PLGA) have made substantial progress. Herein, we discuss PLGA properties with seminal approaches in the development of LAIs, the role of molecular dynamic simulations of polymer-drug interactions, and their effects on quality attributes. We also outline the landscape of various advanced PLGA-based and a few non-PLGA LAI technologies; their design, delivery, and challenges from laboratory scale to preclinical and clinical use; and commercial products incorporating the importance of end-user preferences.

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.

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

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