Yeast Microcapsule Mediated Natural Products Delivery for Treating Ulcerative Colitis through Anti-Inflammatory and Regulation of Macrophage Polarization

Recent developments and new directions in the use of natural products for the treatment of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) represents a significant global health challenge, and there is an urgent need to explore novel therapeutic interventions. Natural products have demonstrated highly promising effectiveness in the treatment of IBD.

PURPOSE

This study systematically reviews the latest research advancements in leveraging natural products for IBD treatment.

METHODS

This manuscript strictly adheres to the PRISMA guidelines. Relevant literature on the effects of natural products on IBD was retrieved from the PubMed, Web of Science and Cochrane Library databases using the search terms "natural product," "inflammatory bowel disease," "colitis," "metagenomics", "target identification", "drug delivery systems", "polyphenols," "alkaloids," "terpenoids," and so on. The retrieved data were then systematically summarized and reviewed.

RESULTS

This review assessed the different effects of various natural products, such as polyphenols, alkaloids, terpenoids, quinones, and others, in the treatment of IBD. While these natural products offer promising avenues for IBD management, they also face challenges in terms of clinical translation and drug discovery. The advent of metagenomics, single-cell sequencing, target identification techniques, drug delivery systems, and other cutting-edge technologies heralds a new era in overcoming these challenges.

CONCLUSION

This paper provides an overview of current research progress in utilizing natural products for the treatment of IBD, exploring how contemporary technological innovations can aid in discovering and harnessing bioactive natural products for the treatment of IBD.

Colon Targeting pH-Responsive Coacervate Microdroplets for Treatment of Ulcerative Colitis

Ulcerative colitis (UC), an immune-mediated chronic inflammatory disease, drastically impacts patients' quality of life and increases their risk of colorectal cancer worldwide. However, effective oral targeted delivery and retention of drugs in colonic lesions are still great challenges in the treatment of UC. Coacervate microdroplets, formed by liquid-liquid phase separation, are recently explored in drug delivery as the simplicity in fabrication, spontaneous enrichment on small molecules and biological macromolecules, and high drug loading capacity. Herein, in this study, a biocompatible diethylaminoethyl-dextran hydrochloride/sodium polyphenylene sulfonate coacervates, coated with eudragit S100 to improve the stability and colon targeting ability, named EU-Coac, is developed. Emodin, an active ingredient in traditional Chinese herbs proven to alleviate UC symptoms, is loaded in EU-Coac (EMO@EU-Coac) showing good stability in gastric acid and pepsin and pH-responsive release behavior. After oral administration, EMO@EU-Coac can effectively target and retain in the colon, displaying good therapeutic effects on UC treatment through attenuating inflammation and oxidative stress response, repairing colonic epithelia, as well as regulating intestinal flora balance. In short, this study provides a novel and facile coacervate microdroplet delivery system for UC treatment.

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.

Microencapsule delivery systems of functional substances for precision nutrition

Microencapsulation, a typical core-shell structure technology, encapsulates functional active ingredients for protection, controlled release, and targeted delivery. In precise nutrition, the focus is on utilizing microcapsule delivery systems for personalized dietary supplements and disease intervention. This chapter outlines the morphological structure of microcapsules, common wall materials, and preparation techniques. It discusses the characteristics of different hydrophilic and lipophilic functional factors and their function as dietary supplements. The role of microencapsulation on the controlled release, odor masking, and enhanced bioavailability of functional factors is explored. Additionally, the application of microcapsule delivery systems in nutritional interventions for diseases like inflammatory bowel disease, alcoholic/fatty liver disease, diabetes, and cancer is introduced in detail. Lastly, the chapter proposes the future developments of anticipation in responsive wall materials for precise nutrition interventions, including both challenges and opportunities.

Bletilla striata Polysaccharide-/Chitosan-Based Self-Healing Hydrogel with Enhanced Photothermal Effect for Rapid Healing of Diabetic Infected Wounds via the Regulation of Microenvironment

The management of diabetic ulcers poses a significant challenge worldwide, and persistent hyperglycemia makes patients susceptible to bacterial infections. Unfortunately, the overuse of antibiotics may lead to drug resistance and prolonged infections, contributing to chronic inflammation and hindering the healing process. To address these issues, a photothermal therapy technique was incorporated in the preparation of wound dressings. This innovative solution involved the formulation of a self-healing and injectable hydrogel matrix based on the Schiff base structure formed between the oxidized Bletilla striata polysaccharide (BSP) and hydroxypropyltrimethylammonium chloride chitosan. Furthermore, the introduction of CuO nanoparticles encapsulated in polydopamine imparted excellent photothermal properties to the hydrogel, which promoted the release of berberine (BER) loaded on the nanoparticles and boosted the antibacterial performance. In addition to providing a reliable physical protection to the wound, the developed hydrogel, which integrated the herbal components of BSP and BER, effectively accelerated wound closure via microenvironment regulation, including alleviated inflammatory reaction, stimulated re-epithelialization, and reduced oxidative stress based on the promising results from cell and animal experiments. These impressive outcomes highlighted their clinical potential in safeguarding the wound against bacterial intrusion and managing diabetic ulcers.

Berberine: Potential preventive and therapeutic strategies for human colorectal cancer

Colorectal cancer (CRC) is a common digestive tract tumor, with incidences continuing to rise. Although modern medicine has extended the survival time of CRC patients, its adverse effects and the financial burden cannot be ignored. CRC is a multi-step process and can be caused by the disturbance of gut microbiome and chronic inflammation's stimulation. Additionally, the presence of precancerous lesions is also a risk factor for CRC. Consequently, scientists are increasingly interested in identifying multi-target, safe, and economical herbal medicine and natural products. This paper summarizes berberine's (BBR) regulatory mechanisms in the occurrence and development of CRC. The findings indicate that BBR regulates gut microbiome homeostasis and controls mucosal inflammation to prevent CRC. In the CRC stage, BBR inhibits cell proliferation, invasion, and metastasis, blocks the cell cycle, induces cell apoptosis, regulates cell metabolism, inhibits angiogenesis, and enhances chemosensitivity. BBR plays a role in the overall management of CRC. Therefore, using BBR as an adjunct to CRC prevention and treatment could become a future trend in oncology.

MnO2 and roflumilast-loaded probiotic membrane vesicles mitigate experimental colitis by synergistically augmenting cAMP in macrophage

BACKGROUND

Ulcerative colitis (UC) is one chronic and relapsing inflammatory bowel disease. Macrophage has been reputed as one trigger for UC. Recently, phosphodiesterase 4 (PDE4) inhibitors, for instance roflumilast, have been regarded as one latent approach to modulating macrophage in UC treatment. Roflumilast can decelerate cyclic adenosine monophosphate (cAMP) degradation, which impedes TNF-α synthesis in macrophage. However, roflumilast is devoid of macrophage-target and consequently causes some unavoidable adverse reactions, which restrict the utilization in UC.

RESULTS

Membrane vesicles (MVs) from probiotic Escherichia coli Nissle 1917 (EcN 1917) served as a drug delivery platform for targeting macrophage. As model drugs, roflumilast and MnO2 were encapsulated in MVs (Rof&MnO2@MVs). Roflumilast inhibited cAMP degradation via PDE4 deactivation and MnO2 boosted cAMP generation by activating adenylate cyclase (AC). Compared with roflumilast, co-delivery of roflumilast and MnO2 apparently produced more cAMP and less TNF-α in macrophage. Besides, Rof&MnO2@MVs could ameliorate colitis in mouse model and regulate gut microbe such as mitigating pathogenic Escherichia-Shigella and elevating probiotic Akkermansia.

CONCLUSIONS

A probiotic-based nanoparticle was prepared for precise codelivery of roflumilast and MnO2 into macrophage. This biomimetic nanoparticle could synergistically modulate cAMP in macrophage and ameliorate experimental colitis.

Construction of hyaluronic acid-functionalized magnolol nanoparticles for ulcerative colitis treatment

Oral targeted anti-inflammatory drugs have garnered significant interest in treating ulcerative colitis (UC) due to their potential in reducing medical costs and enhancing treatment efficacy. Magnolol (Mag), a natural anti-inflammatory compound, has demonstrated protective effects against UC. However, its application as an alternative therapeutic agent for UC is limited by poor gastrointestinal stability and inadequate accumulation at inflamed colonic lesions. This study introduces a novel nanoparticle (NPs) formulation based on Mag, functionalized with hyaluronic acid (HA) for targeted UC therapy. Bovine serum albumin (BSA) was modified with 2-thiamine hydrochloride to synthesize BSA·SH. Thiol-ene click reaction with Mag led to the formation of BSA·SH-Mag NPs, which were further modified with HA through dehydration condensation, regular spherical inflammation-targeting HA-BSA·SH-Mag nanoparticles with a charge of -23.6 mV and a particle size of 403 ± 4 nm were formed. In vitro studies revealed significant macrophage targeting and enhanced uptake by colon epithelial cells. Oral administration of HA-BSA·SH-Mag facilitated colon mucosal barrier repair by modulating pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), anti-inflammatory cytokines (IL-10), and tight junction proteins (ZO-1, Claudin, Occludin). Crucially, HA-BSA·SH-Mag was found to inhibit the JAK2/STAT3/NF-κB signaling pathway, reducing DSS-induced colon tissue inflammation. This research provides valuable insights into the oral use of natural compounds in UC therapy, highlighting the therapeutic potential of HA-BSA·SH-Mag NPs.

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.

Multi-targeting inulin-based nanoparticles with cannabidiol for effective prevention of ulcerative colitis

The pathogenesis of ulcerative colitis (UC) is closely related to severe inflammation, damaged colonic mucosal barrier, increased oxidative stress and intestinal ecological imbalance. However, due to the nonspecific distribution and poor bioavailability of drugs, UC treatment is still a serious challenge. Here, a mitochondria/colon dual targeted nanoparticles based on redox response was developed to effectively alleviate UC. Cannabidiol nanoparticles (CBD NPs) with a particle size of 143.2 ± 3.11 nm were prepared by self-assembly using polymers (TPP-IN-LA) obtained by modifying inulin with (5-carboxypentyl) triphenyl phosphonium bromide (TPP) and α-lipoic acid (α-LA). Excitingly, the constructed CBD NPs showed excellent mitochondrial targeting, with a Pearson correlation coefficient of 0.76 at 12 h. The results of animal imaging in vivo showed that CBD NPs could be effectively accumulated in colon tissue. Not only that, CBD showed significant glutathione stimulated release in the presence of 10 mM glutathione at pH 7.4. The results of in vivo animal experiments showed that CBD NPs significantly ameliorated DSS-induced colonic inflammation by modulating the TLR4-NF-κB signaling pathway. Moreover, CBD NPs significantly improved the histological damage of colon in UC mice, increased the expression level of tight junction protein ZO-1, and effectively restored the intestinal mucosal barrier function and intestinal mucosal permeability. More importantly, CBD NPs significantly improved the species composition, abundance and amount of short chain fatty acids of intestinal flora in UC mice, thus effectively maintaining the balance of intestinal flora. The dual-targeted and glutathione-responsive nanoparticles prepared in this study provide a promising idea for achieving targeted delivery of CBD for effective treatment of UC.

Yeast glucan particles: An express train for oral targeted drug delivery systems

As an emerging drug delivery vehicle, yeast glucan particles (YGPs) derived from yeast cells could be specifically taken up by macrophages. Therefore, these vehicles could rely on the recruitment of macrophages at the site of inflammation and tumors to enable targeted imaging and drug delivery. This review summarizes recent advances in the application of YGPs in oral targeted delivery systems, covering the basic structure of yeast cells, methods for pre-preparation, drug encapsulation and characterization. The mechanism and validation of the target recognition interaction of YGPs with macrophages are highlighted, and some inspiring cases are presented to show that yeast cells have promising applications. The future chances and difficulties that YGPs will confront are also emphasized throughout this essay. YGPs are not only the "armor" but also the "compass" of drugs in the process of targeted drug transport. This system is expected to provide a new idea about the oral targeted delivery of anti-inflammatory and anti-tumor drugs, and furthermore offer an effective delivery strategy for targeted therapy of other macrophage-related diseases.

Exploring β-glucan as a micro-nano system for oral delivery targeted the colon

The critical role of oral colon-specific delivery systems (OCDDS) is important for delivering active agents to the colon and rectum specifically via the oral route. The use of micro/nanostructured OCDDS further improves drug stability, bioavailability, and retention time, leading to enhanced therapeutic effects. However, designing micro/nanoscale OCDDSs is challenging due to pH changes, enzymatic degradation, and systemic absorption and metabolism. Biodegradable natural polysaccharides are a promising solution to these problems, and β-glucan is one of the most promising natural polysaccharides due to its unique structural features, conformational flexibility, and specific processing properties. This review covers the diverse chemical structures of β-glucan, its benefits (biocompatibility, easy modification, and colon-specific degradation), and various β-glucan-based micro/nanosized OCDDSs, as well as their drawbacks. The potential of β-glucan offers exciting new opportunities for colon-specific drug delivery.

Oral hydrogel nanoemulsion co-delivery system treats inflammatory bowel disease via anti-inflammatory and promoting intestinal mucosa repair

BACKGROUND

Due to oral nano-delivery systems for the treatment of inflammatory bowel disease (IBD) are often failed to accumulated to the colonic site and could not achieve controlled drug release, it's urgent to develop a microenvironment responsive drug delivery to improve therapy efficacy. Inflammation at the IBD site is mainly mediated by macrophages, which are the key effector cells. Excessive inflammation leads to oxidative stress and intestinal mucosal damage. The use of curcumin (CUR) and emodin (EMO) together for the treatment of IBD is promising due to their respective anti-inflammatory and intestinal mucosal repair effects. In view of the pH gradient environment of gastrointestinal tract, here we prepared pH-responsive sodium alginate (SA) hydrogel-coated nanoemulsions to co-deliver CUR and EMO (CUR/EMO NE@SA) to achieve controlled drug release and specifically target macrophages of the colon.

RESULTS

In this study, a pH-responsive CUR/EMO NE@SA was successfully developed, in which the CUR/EMO NE was loaded by chitosan and further crosslinked with sodium alginate. CUR/EMO NE@SA had a pH-responsive property and could achieve controlled drug release in the colon. The preparation could significantly alleviate and improve the colon inflammatory microenvironment by decreasing TNF-α and IL-6 expression, increasing IL-10 expression, scavenging reactive oxygen species in macrophages, and by ameliorating the restoration of intestinal mucosal tight junction protein expression. Furthermore, we revealed the molecular mechanism of the preparation for IBD treatment, which might due to the CUR and EMO synergic inhibition of NF-κB to improve the pro-inflammatory microenvironment. Our study provides a new IBD therapy strategy via synergically inhibiting inflammatory, repairing mucosal and clearing ROS by pH-sensitive hydrogel-encapsulated nanoemulsion drug delivery system, which might be developed for other chronic inflammatory disease treatment.

CONCLUSIONS

It's suggested that pH-sensitive hydrogel-coated nanoemulsion-based codelivery systems are a promising combinatorial platform in IBD.

Biocompatible smart micro/nanorobots for active gastrointestinal tract drug delivery

INTRODUCTION

Oral delivery is the most commonly used route of drug administration owing to good patient compliance. However, the gastrointestinal (GI) tract contains multiple physiological barriers that limit the absorption efficiency of conventional passive delivery systems resulting in a low drug concentration reaching the diseased sites. Micro/nanorobots can convert energy to self-propulsive force, providing a novel platform to actively overcome GI tract barriers for noninvasive drug delivery and treatment.

AREAS COVERED

In this review, we first describe the microenvironments and barriers in the different compartments of the GI tract. Afterward, the applications of micro/nanorobots to overcome GI tract barriers for active drug delivery are highlighted and discussed. Finally, we summarize and discuss the challenges and future prospects of micro/nanorobots for further clinical applications.

EXPERT OPINION

Micro/nanorobots with the ability to autonomously propel themselves and to load, transport, and release payloads on demand are ideal carriers for active oral drug delivery. Although there are many challenges to be addressed, micro/nanorobots have great potential to introduce a new era of drug delivery for precision therapy.

Recombinant hemagglutinin displaying on yeast reshapes congenital lymphocyte subsets to prompt optimized systemic immune protection against avian influenza infection

Introduction

Prophylactic vaccination is regarded as the most effective means to control avian flu infection. Currently, there is a need for a universal vaccine that provides broad and long-lasting protection against influenza virus. Meanwhile, although yeast-based vaccines have been used in clinic, studies are still required to further understand the molecular mechanism of yeast-based vaccines under physiological conditions.

Methods

We generated a yeast-based vaccine against influenza hemagglutinin (HA) of H5, H7 and H9 using surface displaying technology and evaluated the protective efficacy of chickens after exposure to H9N2 influenza virus.

Results

Oral yeast vaccine provided less clinical syndrome, reduced viral loading and alleviated airway damage significantly. Compared to the commercial inactivated vaccine, yeast vaccine stimulated the activation of splenic NK and APCs cells and boosted TLR7-IRF7-IFN signaling in spleen. Meanwhile, γδ T cells in the bursa of Fabricius were activated and the innate lymphoid cells (ILCs) in the bursa of Fabricius promoted the CILPs to differentiate to ILC3 cells in oral yeast birds. Moreover, the reshaped gut microbiota and a suppressed Th17-IL17-mediated inflammation in intestine was observed in oral yeast chickens, which might facilitate the recovery of intestinal mucosal immunity upon virus infection. Collectively, our findings suggest that oral yeast based multivalent bird flu vaccines provide an attractive strategy to update host defense function via reshapes of multi-systemic immune homeostasis.

Encapsulation of Polyphenolic Compounds Based on Hemicelluloses to Enhance Treatment of Inflammatory Bowel Diseases and Colorectal Cancer

Inflammatory bowel diseases (IBD) and colorectal cancer (CRC) are difficult to cure, and available treatment is associated with troubling side effects. In addition, current therapies have limited efficacy and are characterized by high costs, and a large segment of the IBD and CRC patients are refractive to the treatment. Moreover, presently used anti-IBD therapies in the clinics are primarily aimed on the symptomatic control. That is why new agents with therapeutic potential against IBD and CRC are required. Currently, polyphenols have received great attention in the pharmaceutical industry and in medicine due to their health-promoting properties. They may exert anti-inflammatory, anti-oxidative, and anti-cancer activity, via inhibiting production of pro-inflammatory cytokines and enzymes or factors associated with carcinogenesis (e.g., matrix metalloproteinases, vascular endothelial growth factor), suggesting they may have therapeutic potential against IBD and CRC. However, their use is limited under both processing conditions or gastrointestinal interactions, reducing their stability and hence their bioaccessibility and bioavailability. Therefore, there is a need for more effective carriers that could be used for encapsulation of polyphenolic compounds. In recent years, natural polysaccharides have been proposed for creating carriers used in the synthesis of polyphenol encapsulates. Among these, hemicelluloses are particularly noteworthy, being characterized by good biocompatibility, biodegradation, low immunogenicity, and pro-health activity. They may also demonstrate synergy with the polyphenol payload. This review discusses the utility and potential of hemicellulose-based encapsulations of polyphenols as support for treatment of IBD and CRC.

Chemodynamic/Photothermal Synergistic Cancer Immunotherapy Based on Yeast Microcapsule-Derived Au/Pt Nanoparticles

In recent years, microbiota-based tumor immunotherapy has become a hotspot in cancer research. However, the use of microorganisms alone to activate the immune response for antitumor therapy was unsatisfactory. In this study, we biosynthesized gold nanoparticles (AuNPs) and platinum nanoparticles (PtNPs) based on yeast microcapsules to activate the immune response for antitumor treatment in synergy with chemodynamic therapy (CDT) and photothermal therapy (PTT). We generated AuNPs and PtNPs on yeast microcapsules (YAP) and fabricated nanoscale particles (Bre-YAP) by ultrasonic fragmentation and differential centrifugation. Bre-YAP retained the glucan component of yeast as an adjuvant; in the meantime, these two kinds of metal nanoparticles contained were excellent CDT and PTT mediators. By inspection, they could reach a high level of distribution in tumors and tumor-draining lymph nodes (TDLNs). Under the laser irradiation of tumors, this immunological nanomaterial significantly remodeled the microenvironments of tumors and TDLNs. The primary tumors were effectively inhibited or even eradicated, and the overall survival of mice was significantly improved as well. Therefore, yeast microcapsule-based Bre-YAP with immune properties could be used as an effective cancer treatment modality.

The application of natural product-delivering micro/nano systems in the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a type of recurrent intestinal diseases. Natural product molecules have been gradually developed into an important source of anti-inflammatory drugs for treating IBD owing to their high anti-inflammatory activity, well known safety, structural specificity and therapeutic mechanism diversity. However, most of the natural products are restricted by poor solubility in actual application. How to achieve satisfactory bioavailability during the treatment of IBD is one of the urgent problems to be solved in the current research. Micro/nano drug delivery systems could improve the solubility of drugs with targeted delivery of anti-inflammatory drugs to the colon with responsive release property. Therefore, using micro/nano drug delivery systems, the problems mentioned above involving natural product molecules in the treatment of IBD could be solved. According to the compositions of the intestinal tract and inflammatory characteristics of IBD, the strategies of using micro/nano drug delivery systems for natural products could be summarized in two steps: targeted delivery and responsive release. In this review, the targeted and responsive release strategies of the micro/nano drug delivery systems combined with their anti-inflammatory effects in IBD animal models to illustrate that the proposed strategies could be potential treatments for symptomatic IBD are described.

Milmed Yeast Alters the LPS-Induced M1 Microglia Cells to Form M2 Anti-Inflammatory Phenotype

Microglial cells polarized towards a proinflammatory phenotype are considered the main cellular players of neuroinflammation, underlying several neurodegenerative diseases. Many studies have suggested that imbalance of the gut microbial composition is associated with an increase in the pro-inflammatory cytokines and oxidative stress that underlie chronic neuroinflammatory diseases, and perturbations to the gut microbiota were detected in neurodegenerative conditions such as Parkinson's disease and Alzheimer's disease. The importance of gut-brain axis has been uncovered and the relevance of an appropriate microbiota balance has been highlighted. Probiotic treatment, rebalancing the gut microbioma, may reduce inflammation. We show that Milmed yeast, obtained from S. cerevisiae after exposure to electromagnetic millimeter wavelengths, induces a reversal of LPS-M1 polarized microglia towards an anti-inflammatory phenotype, as demonstrated morphologically by the recovery of resting phenotype by microglia, by the decrease in the mRNAs of IL-1β, IL-6, TNF-α and in the expression of iNOS. Moreover, Milmed stimulated the secretion of IL-10 and the expression of Arginase-1, cell markers of M2 anti-inflammatory polarized cells. The present findings data suggest that Milmed may be considered to be a probiotic with diversified anti-inflammatory activity, capable of directing the polarization of microglial cells.

Oral Cell-Targeted Delivery Systems Constructed of Edible Materials: Advantages and Challenges

Cell-targeted delivery is an advanced strategy which can effectively solve health problems. However, the presence of synthetic materials in delivery systems may trigger side effects. Therefore, it is necessary to develop cell-targeted delivery systems with excellent biosafety. Edible materials not only exhibit biosafety, but also can be used to construct cell-targeted delivery systems such as ligands, carriers, and nutraceuticals. Moreover, oral administration is the appropriate route for cell-targeted delivery systems constructed of edible materials (CDSEMs), which is the same as the pattern of food intake, resulting in good patient compliance. In this review, relevant studies of oral CDSEMs are collected to summarize the construction method, action mechanism, and health impact. The gastrointestinal stability of delivery systems can be improved by anti-digestible materials. The design of the surface structure, shape, and size of carrier is beneficial to overcoming the mucosal barrier. Additionally, some edible materials show dual functions of a ligand and carrier, which is conductive to simplifying the design of CDSEMs. This review can provide a better understanding and prospect for oral CDSEMs and promote their application in the health field.

A Biomarker-Responsive Nanosystem with Colon-Targeted Delivery for Ulcerative Colitis's Detection and Treatment with Optoacoustic/NIR-II Fluorescence Imaging

Ulcerative colitis (UC) is a prevalent idiopathic inflammatory disease which causes such complications as intestinal perforation, obstruction, and bleeding, and thus deleteriously impacting people's normal work and quality of life. Hence, accurate diagnosis of UC is crucial in terms of planning optimal treatment plan. Herein, a pH/reactive oxygen species (ROS) dual-responsive nanosystem (BM@EP) is developed for UC's detection and therapy. BM@EP is composed of a chromophore-drug dyad and the enteric coating. The chromophore-drug dyad (BOD-XT-DHM) is synthesized by linking the chromophore (BOD-XT-BOH) and a flavonoid drug (dihydromyricetin DHM) through boronate ester bond. The enteric coating includes Eudragit S100 and poly(lactic-co-glycolic acid) (PLGA), the former is commonly employed as a pH-dependent polymer coating excipient so as to attain colon-targeted delivery, and the latter has been widely used as an excipient for the controlled-extended release. After oral administration, BM@EP delivers the dyad (BOD-XT-DHM) into the colon and releases the dyad molecules by being triggered by the alkaline pH in t colon, thereafter upon being stimulated by overexpressed H₂ O₂ in the inflamed colon, the boronate bond in the dyad is broken down and correspondingly the drug DHM is released for UC therapy, simultaneously the chromophore is released for near-infrared second window (NIR-II) fluorescence and optoacoustic imaging for UC diagnosis and recovery evaluation.