A Colon-Targeted Oral Probiotics Delivery System Using an Enzyme-Triggered Fuse-Like Microcapsule

Polyelectrolyte complexes of chitosan and hyaluronic acid or carboxymethylpullulan and their aminoguaiacol derivatives with biological activities as potential drug delivery systems

Polyelectrolyte complexes (PECs) were elaborated from chitosan as cationic polymer and carboxy-methylpullulan (CMP), hyaluronic acid (HA) and their derivatives grafted with aminoguaiacol (G) with different degrees of substitution (DSGA) with the aim of obtaining nanogels for drug delivery. For each couple of polysaccharides, the charge ratios giving the smaller size with the lower PDI were selected to produce PECs. CMP_CHIT and CMP-G_CHIT PECs had smaller sizes (220-280 nm) than HA_CHIT and HA-G_CHIT PECs (280-390 nm). PECs were stable at 4 °C during 28 days at pH 5. In phosphate buffer saline (PBS) at pH 7.4, at 4 °C, a better stability of PECs based on CMP-G derivatives was observed. The hydrophobic associations between aminoguaiacol groups (highlighted by measurements of pyrene fluorescence) led to a better PECs' stabilization in PBS. The PECs' antioxidant and antibacterial activities were demonstrated and related to the DSGA. Diclofenac and curcumin were used as drug models: their loading reached 260 and 53 μg/mg PEC, respectively. The release of diclofenac in PBS at 37 °C followed a quasi-Fickian diffusion mechanism with release constant between 0.88 and 1.04 h-1. The curcumin release followed a slow linear increase in PBS/EtOH (60/40 V/V) with an effect of DSGA.

Interfacial-engineered living drugs with "ON/OFF" switching for oral delivery

Living drugs offer a new frontier in medicine, paving the way for personalized and potentially curative treatments. A customized living drug generally requires specialized technologies for highly effective and selective delivery to lesion locations. In this study, we explored an interfacial engineering method for living drugs by wrapping them with a "stealth coating", achieving "ON/OFF" switching of the communications between probiotics and the gastrointesinal (GI) tract. This maximized the bioactivity of living drugs following oral administration to exempt acidic insults and then significantly improved the retention through the gastrointestinal tract. With the notable ability to improve oral availability, the interfacial-engineered living drugs represent remarkable effects for enhanced oral delivery and treatment efficacy in the dextran sulfate sodium (DSS)-induced acute colitis model. We believe that this work has the potential to revolutionize medicine by precisely targeting and increasing curative activity in the future of disease treatment.

Dress me an outfit: advanced probiotics hybrid systems for intelligent IBD therapy

Inflammation bowel disease (IBD) has emerged as a public health challenge worldwide; with high incidence and rapid prevalence, it has troubled billions of people and further induced multitudinous systemic complications. Recent decade has witnessed the vigorous application of food-borne probiotics for IBD therapy; however, the complicated and changeable environments of digestive tract have forced probiotics to face multiple in vivo pressures, consequently causing unsatisfied prophylactic or therapeutic efficacy attributed to off-targeted arrival, damaged viability, insufficient colonization efficiency, etc. Fortunately, arisen hybrid technology has provided versatile breakthroughs for the targeted transplantation of probiotics. By ingeniously modifying probiotics to form probiotics hybrid systems (PHS), the biological behaviors of probiotics in vivo could be mediated, the interactions between probiotics with intestinal components can be facilitated, and diverse advanced probiotic-based therapies for IBD challenge can be developed, which attribute to the intelligent response to microenvironment of PHS, and intelligent design of PHS for multiple functions combination. In this review, various PHS were categorized and their intestinal behaviors were elucidated systematically, their therapeutic effects and intrinsic mechanism were further analyzed. Besides, shortages of present PHS and the corresponding solutions have been discussed, based on which the future perspectives of this field have also been proposed. The undeniable fact is that PHS show an incomparable future to bring the next generation of advanced food science.

Colon-targeted oral nanoliposomes loaded with psoralen alleviate DSS-induced ulcerative colitis

Oral administration, while convenient, but complex often faces challenges due to the complexity of the digestive environment. In this study, we developed a nanoliposome (NLP) encapsulating psoralen (P) and coated it with chitosan (CH) and pectin (PT) to formulate PT/CH-P-NLPs. PT/CH-P-NLPs exhibit good biocompatibility, superior to liposomes loaded with psoralen and free psoralen alone. After oral administration, PT/CH-P-NLPs remain stable in the stomach and small intestine, followed by a burst release of psoralen after reaching the slightly alkaline and gut microbiota-rich colon segment. In the DSS-induced ulcerative colitis of mice, PT/CH-P-NLPs showed significant effects on reducing inflammation, mitigating oxidative stress, protecting the integrity of the colon mucosal barrier, and modulating the gut microbiota. In conclusion, the designed nanoliposomes demonstrated the effective application of psoralen in treating ulcerative colitis.

Layer-by-layer coated probiotics with chitosan and liposomes exhibit enhanced therapeutic effects for DSS-induced colitis in mice

Probiotic therapy has emerged as a promising approach for the treatment of gastrointestinal diseases, offering advantages in terms of safety and convenience. However, oral probiotics encounter significant challenges, including exposure to a hostile gastric environment with low pH, bile salts, elevated levels of reactive oxygen species (ROS), and damage to the protective mucus layer. These factors reduce probiotic survival rates and limit their physiological activity. To address these challenges, we developed a layer-by-layer coated probiotics with curcumin-loaded liposome and polymer. Through DSS-induced colitis mice experiments, we demonstrated that the coated probiotics exhibited an improved survival rate in the gastrointestinal tract and enhanced adhesion to the intestinal mucosa. Furthermore, multi-layered coated probiotics exhibited remarkable efficacy in alleviating colitis by efficiently repairing the gut barrier, modulating gut microbial homeostasis, and reducing bacterial motility at sites of colonic inflammation. Our innovative approach holds promise for effectively treating gastrointestinal diseases.

Oral delivery of probiotics using single-cell encapsulation

Adequate intake of live probiotics is beneficial to human health and wellbeing because they can help treat or prevent a variety of health conditions. However, the viability of probiotics is reduced by the harsh environments they experience during passage through the human gastrointestinal tract (GIT). Consequently, the oral delivery of viable probiotics is a significant challenge. Probiotic encapsulation provides a potential solution to this problem. However, the production methods used to create conventional encapsulation technologies often damage probiotics. Moreover, the delivery systems produced often do not have the required physicochemical attributes or robustness for food applications. Single-cell encapsulation is based on forming a protective coating around a single probiotic cell. These coatings may be biofilms or biopolymer layers designed to protect the probiotic from the harsh gastrointestinal environment, enhance their colonization, and introduce additional beneficial functions. This article reviews the factors affecting the oral delivery of probiotics, analyses the shortcomings of existing encapsulation technologies, and highlights the potential advantages of single-cell encapsulation. It also reviews the various approaches available for single-cell encapsulation of probiotics, including their implementation and the characteristics of the delivery systems they produce. In addition, the mechanisms by which single-cell encapsulation can improve the oral bioavailability and health benefits of probiotics are described. Moreover, the benefits, limitations, and safety issues of probiotic single-cell encapsulation technology for applications in food and beverages are analyzed. Finally, future directions and potential challenges to the widespread adoption of single-cell encapsulation of probiotics are highlighted.

The application of encapsulation technology in the food Industry: Classifications, recent Advances, and perspectives

Encapsulation technology has been extensively used to enhance the stability, specificity, and bioavailability of essential food ingredients. Additionally, it plays a vital role in improving product quality and reducing production costs. This study presents a comprehensive classification of encapsulation techniques based on the state of different cores (solid, liquid, and gaseous) and offers a detailed description and analysis of these encapsulation methods. Specifically, it introduces the diverse applications of encapsulation technology in food, encompassing areas such as antioxidant, protein activity, physical stability, controlled release, delivery, antibacterial, and probiotics. The potential impact of encapsulation technology is expected to make encapsulation technology a major process and research hotspot in the food industry. Future research directions include applications of encapsulation for enzymes, microencapsulation of biosensors, and novel technologies such as self-assembly. This study provides a valuable theoretical reference for the in-depth research and wide application of encapsulation technology in the food industry.

The single-cell modification strategies for probiotics delivery in inflammatory bowel disease: A review

Oral probiotic therapy has become an increasingly attractive method for treating various diseases, including intestinal barrier dysfunction, inflammatory bowel disease (IBD), and colorectal cancer due to its safety and convenience. However, only a few probiotics after oral gavage can survive the acidic and bile salt conditions of the gastrointestinal tract and colonize the colon to have a nutritional effect on the host. To address these challenges, encapsulation technology has been applied to protect probiotics from harsh gastrointestinal conditions, improve gut adhesion, and reduce immunogenicity. In addition, some of the functional polysaccharides are used to endow probiotics with exogenous functions as prebiotics. In this review, we systematically introduced the advancements of emerging single-cell modification strategies for probiotics in IBD applications. Additionally, we discussed the limitations and perspectives of single-cell modification strategies for probiotics. This review contributed to the development of probiotic delivery systems with higher therapeutic efficacy against colitis.

Protein/polysaccharide-based hydrogels loaded probiotic-mediated therapeutic systems: A review

The natural characteristics of protein/polysaccharide-based hydrogels, as a potential drug delivery platform, have attracted extensive attention. Probiotics have attracted renewed interest in drug research because of their beneficial effects on host health. The idea of using probiotics loaded on protein/polysaccharide-based hydrogels as potential drugs to treat different diseases has been put forward and shows great prospects. Based on this, in this review, we highlight the design strategy of hydrogels loaded probiotic-mediated therapy systems and review the potential diseases that have been proved to be treatable in the laboratory, including promoting wound healing and improving intestinal health and vaginal health, and discuss the challenges existing in the current design.

Culture-Delivery Live Probiotics Dressing for Accelerated Infected Wound Healing

Probiotic therapy in infected wound healing is hindered by its low viability and colonization efficiency during treatments. Developing dressings that maintain metabolic activity and prevent the potential leakage of probiotics is imperative. Herein, a culture-delivery live probiotics hydrogel dressing is designed and synthesized, formed by gelatin modified with norbornene (GelNB) and sulfhydryl (GelSH), distributing Lactobacillus reuteri (L. reuteri)-laden alginate microspheres (AlgMPs). GelNB-GelSH hydrogel (GelNBSH) incorporating AlgMPs embedding L. reuteri (GelNBSH-L) possesses bioprintability and efficient polymerization that can maintain the activity of L. reuteri in situ, promote its proliferation, and limit its leakage. Thereby, GelNBSH-L achieved a sustainable antimicrobial effect against both S. aureus and E. coli (>90%). Above all, the results show that GelNBSH-L could ensure propitious viability and efficient antibacterial properties of probiotics, effectively inhibit the further development of bacterial infectious wounds and shorten the repair cycle, aiding in ameliorating future clinical probiotic biotherapy.

Tri-Layer Core-Shell Fibers from Coaxial Electrospinning for a Modified Release of Metronidazole

Polymers are the backbone of drug delivery. Electrospinning has greatly enriched the strategies that have been explored for developing novel drug delivery systems using polymers during the past two decades. In this study, four different kinds of polymers, i.e., the water-soluble polymer poly (vinyl alcohol) (PVA), the insoluble polymer poly(ε-caprolactone) (PCL), the insoluble polymer Eudragit RL100 (ERL100) and the pH-sensitive polymer Eudragit S100 (ES100) were successfully converted into types of tri-layer tri-polymer core-shell fibers through bi-fluid coaxial electrospinning. During the coaxial process, the model drug metronidazole (MTD) was loaded into the shell working fluid, which was an emulsion. The micro-formation mechanism of the tri-layer core-shell fibers from the coaxial emulsion electrospinning was proposed. Scanning electron microscope and transmission electron microscope evaluations verified the linear morphology of the resultant fibers and their obvious tri-layer multiple-chamber structures. X-ray diffraction and Fourier transform infrared spectroscopy measurements demonstrated that the drug MTD presented in the fibers in an amorphous state and was compatible with the three polymeric matrices. In vitro dissolution tests verified that the three kinds of polymer could act in a synergistic manner for a prolonged sustained-release profile of MTD in the gut. The drug controlled-release mechanisms were suggested in detail. The protocols reported here pioneer a new route for creating a tri-layer core-shell structure from both aqueous and organic solvents, and a new strategy for developing advanced drug delivery systems with sophisticated drug controlled-release profiles.

Nanocoating of lactic acid bacteria: properties, protection mechanisms, and future trends

Lactic acid bacteria (LAB) is a type of probiotic that may benefit intestinal health. Recent advances in nanoencapsulation provide an effective strategy to protect them from harsh conditions via surface functionalization coating techniques. Herein, the categories and features of applicable encapsulation methods are compared to highlight the significant role of nanoencapsulation. Commonly used food-grade biopolymers (polysaccharides and protein) and nanomaterials (nanocellulose and starch nanoparticles) are summarized along with their characteristics and advances to demonstrate enhanced combination effects in LAB co-encapsulation. Nanocoating for LAB provides an integrity dense or smooth layer attributed to the cross-linking and assembly of the protectant. The synergism of multiple chemical forces allows for the formation of subtle coatings, including electrostatic attractions, hydrophobic interactions, π-π, and metallic bonds. Multilayer shells have stable physical transition properties that could increase the space between the probiotic cells and the outer environment, thus delaying the microcapsules burst time in the gut. Probiotic delivery stability can be promoted by enhancing the thickness of the encapsulated layer and nanoparticle binding. Maintenance of benefits and minimization of nanotoxicity are desirable, and green synthesized nanoparticles are emerging. Future trends include optimized formulation, especially using biocompatible materials, protein or plant-based materials, and material modification.

Bacteria-Loaded Gastro-Retention Oral Delivery System for Alcohol Abuse

Alcohol abuse is harmful to human health, and many strategies have been developed to retard this harm through protecting liver or activating relative enzymes. In this study, a new strategy of decreasing the alcohol absorption directly depending on the dealcoholization by the bacteria in the upper gastrointestinal (GI) tract was reported. To realize this, a bacteria-loaded gastro-retention oral delivery system with pore structure was constructed through emulsification/internal gelation, which could relieve acute alcohol intoxication in mice successfully. It was found that this bacteria-loaded system kept the above 30% suspension ratio in the simulated gastric fluid for 4 min, displayed good protection effect for the bacteria, and decreased the alcohol concentration from 50 to 30% below within 24 h in vitro. The in vivo imaging results demonstrated that it remained in the upper GI tract until 24 h and reduced 41.9% alcohol absorption. The mice with oral administration of the bacteria-loaded system were found with normal gait, smooth coat, and less liver damage. Although the intestinal flora distribution was influenced slightly during the oral administration, it could restore to normal levels only one day after stopping oral administration quickly, suggesting good biosafety. In conclusion, these results revealed that the bacteria-loaded gastro-retention oral delivery system might intake alcohol molecules rapidly and has huge potential in the treatment of alcohol abuse.

Multishell Colloidosome Platform with Sequential Gastrointestinal Resistance for On-Demand Probiotic Delivery

Probiotic-based oral therapy can potentially prevent and treat diseases by regulating the balance of intestinal flora. However, significant loss of viability and bioactivity of probiotics before reaching the colon results in low delivery efficiency and therapeutic effects, which limits their clinical applications. Here, this work proposes a multishell colloidosome (MSC) platform with sequential gastrointestinal resistance for on-demand probiotic delivery based on biomimetic mineralization and microfluidic technology. Notably, the viability of the decorated probiotics increases 280-fold compared to that of free bacteria during preservation. Because of the sequential gastrointestinal resistance of MSC, encapsulated probiotics exhibit high viability (61%) under continuous exposure to extreme acidity, bile salt erosion, and enzymatic action, whereas free bacteria have a viability of 0%. Moreover, in vitro and in vivo studies reveal that MSC mainly releases probiotics in the colon and improves colonic colonization by probiotics to maintain the integrity of the intestinal barrier and regulate the balance of intestinal flora. Consequently, MSC significantly improves the therapeutic effect on colitis in mice. The MSC platform provides a promising delivery strategy to enhance the efficacy of orally administered probiotics.

Design and Development of Extracellular Matrix Protein-Based Microcapsules as Tools for Bacteria Investigation

The extracellular matrix (ECM) plays an immense role in the homeostasis of tissues and organs, can function as a barrier for infectious agents, but is also exploited by pathogens during infection. Therefore, the development of well-defined 3D ECM models in the form of microcapsules to elucidate the interactions between ECM components and pathogens in confinement and study disease infectivity is important, albeit challenging. Current limitations are mainly attributed to the lack of biocompatible methods for the production of protein-based microcapsules. Herein, hollow ECM-based microcapsules from laminin-111 or laminin-111/collagen IV are generated to investigate the behavior of organisms within confined 3D extracellular matrices. Microcapsules are created using water-in-oil emulsion droplets stabilized by block copolymer surfactants as templates for the charge-mediated attraction of laminin or laminin-collagen proteins to the droplets' inner periphery, allowing for the formation of modular ECM-based microcapsules with tunable biophysical and biochemical properties and organism encapsulation. The release of E. coli-laden ECM-based protein microcapsules into a physiological environment revealed differences in the dynamic behavior of E. coli depending on the constitution of the surrounding ECM protein matrix. The developed ECM-based protein microcapsules have the potential to be implemented in several biomedical applications, including the design of in vitro infection models.

Precise oral delivery systems for probiotics: A review

Probiotics have several health benefits to the host. However, low pH in the stomach, various digestive enzymes and bile salts in the intestine threaten their viability and function. Thus, probiotics need to be protected during gastric transit to address challenges associated with low viability and impaired function. At present, probiotic delivery systems with different trigger mechanisms have been constructed to successfully introduce numerous high-viability probiotics to the intestine. On this basis, the application of non-targeted/targeted probiotic delivery systems in different gut microenvironment and the adjuvant therapeutic effect of probiotic delivery systems on other disease were discussed in detail. It is important to also note that most of the current studies in this area focused on non-targeted probiotic delivery systems. Moreover, changes in intestinal microenvironment under disease state and discontinuous distribution of disease site limit their development. Thus, emphasis were made on the optimization of non-targeted probiotic delivery systems and the necessity of designing more precisely targeted ones.

Microorganisms-An Effective Tool to Intensify the Utilization of Sulforaphane

Sulforaphane (SFN) was generated by the hydrolysis of glucoraphanin under the action of myrosinase. However, due to the instability of SFN, the bioavailability of SFN was limited. Meanwhile, the gut flora obtained the ability to synthesize myrosinase and glucoraphanin, which could be converted into SFN in the intestine. However, the ability of microorganisms to synthesize myrosinase in the gut was limited. Therefore, microorganisms with myrosinase synthesis ability need to be supplemented. With the development of research, microorganisms with high levels of myrosinase synthesis could be obtained by artificial selection and gene modification. Researchers found the SFN production rate of the transformed microorganisms could be significantly improved. However, despite applying transformation technology and regulating nutrients to microorganisms, it still could not provide the best efficiency during generating SFN and could not accomplish colonization in the intestine. Due to the great effect of microencapsulation on improving the colonization ability of microorganisms, microencapsulation is currently an important way to deliver microorganisms into the gut. This article mainly analyzed the possibility of obtaining SFN-producing microorganisms through gene modification and delivering them to the gut via microencapsulation to improve the utilization rate of SFN. It could provide a theoretical basis for expanding the application scope of SFN.

Plant polysaccharides as novel biomaterials for microcapsule construction and therapeutics delivery

Natural polysaccharides derived from medicinal plants, that are Dendrobium (DPS), Lycium barbarum (LBP), Ginseng (GPS), and Poria Cocos (PCP) were firstly combined with sodium alginate (SA) to construct microcapsules and improved the morphology, encapsulation efficiency, Biocompatibility and protective capability in drug loading. Diverse typical therapeutics, including VO₂@ZIF67 nanoparticles, small molecule drugs salvianolic acid B (SaB)/ginsenoside (Rg1), probiotic Bacillus bifidus, and biomacromolecules SDF-1 were wrapped into 1.5 % GPS-0.5 % SA model microcapsules, respectively. Better mobility and formability were significantly observed, and showed 75 % survival rate of probiotics in simulated gastric juice and around 99 % encapsulation efficiency which is higher than single 2 % SA microcapsules. The microcapsules also obtained a delayed release and a higher cell index for SDF-1, which indicated better stability, biocompatibility and protective effect than single 2 % SA microcapsules. This study provides a strategy in developing plant derived polysaccharides as novel materials for the construction and improvement of traditional microcapsules.

Updated design strategies for oral delivery systems: maximized bioefficacy of dietary bioactive compounds achieved by inducing proper digestive fate and sensory attributes

Interest in the application of dietary bioactive compounds (DBC) in healthcare and pharmaceutical industries has motivated researchers to develop functional delivery systems (FDS) aiming to maximize their bioefficacy. As the direct and indirect health benefiting effects of DBC are acknowledged, traditional design principle of FDS aiming at improving the bioavailability of intact DBC is challenged by the updated one, where the maximized bioefficacy of DBC delivered by FDS will be achieved via rationally absorbed at target sites with proper metabolism pathways. This article briefly summarized the absorption and metabolic fates of orally digested DBC along with their direct and indirect mechanisms to perform health benefiting effects. Current strategies in designing the next generation FDS with an emphasis on their modulation effects on the distribution portion between the upper and lower digestive tract, portal vein and lymphatic absorption, human digestive and gut microbiota enzymatic mediated metabolism were highlighted. Updated research progresses of FDS in adjusting sensory attributes of food end products and inducing synergistic effects rooting from matrix materials and co-delivered cargos were also discussed. Challenges as well as future perspectives concerning the precise nutrition and the critical role of delivery systems in dietary intervention were proposed.

Biopolymer-Based Multilayer Microparticles for Probiotic Delivery to Colon

The potential health benefits of probiotics may not be realized because of the substantial reduction in their viability during food storage and gastrointestinal transit. Microencapsulation has been successfully utilized to improve the resistance of probiotics to critical conditions. Owing to the unique properties of biopolymers, they have been prevalently used for microencapsulation of probiotics. However, majority of microencapsulated products only contain a single layer of protection around probiotics, which is likely to be inferior to more sophisticated approaches. This review discusses emerging methods for the multilayer encapsulation of probiotic using biopolymers. Correlations are drawn between fabrication techniques and the resultant microparticle properties. Subsequently, multilayer microparticles are categorized based on their layer designs. Recent reports of specific biopolymeric formulations are examined regarding their physical and biological properties. In particular, animal models of gastrointestinal transit and disease are highlighted, with respect to trials of multilayer microencapsulated probiotics. To conclude, novel materials and approaches for fabrication of multilayer structures are highlighted.

Polymer and Crosslinker Content Influences Performance of Encapsulated Live Biotherapeutic Products

INTRODUCTION

Live biotherapeutic products (LBPs), or therapeutic microbes, are an emerging therapeutic modality for prevention and treatment of gastrointestinal diseases. Since LBPs are living, they are uniquely sensitive to external stresses (e.g., oxygen, acid) encountered during manufacturing, storage, and delivery. Here, we systematically evaluate how polymer and crosslinker concentration affects the performance of an encapsulated LBP toward developing a comprehensive framework for the characterization and optimization of LBP delivery systems.

METHODS

We encapsulate a model LBP, Lactobacillus casei ATCC 393, in calcium chloride (CaCl2)-crosslinked alginate beads, and evaluate how alginate and CaCl2 concentrations influence LBP formulation performance, including: (i) encapsulation efficiency, (ii) shrinkage upon drying, (iii) survival upon lyophilization, (iv) acid resistance, (v) release, and (vi) metabolite secretion. Approaches from microbiology (e.g., colony forming unit enumeration), materials science (e.g., scanning electron microscopy), and pharmaceutical sciences (e.g., release assays) are employed.

RESULTS

LBP-encapsulating alginate beads were systematically evaluated as a function of alginate and CaCl2 concentrations. Specifically: (i) encapsulation efficiency of all formulations was >50%, (ii) all alginate beads shrunk (after lyophilization) and recovered (after rehydration) similarly, (iii) at 10% alginate concentration, lower CaCl2 concentration decreased survival upon lyophilization, (iv) 10% alginate improved acid resistance, (v) sustained release was enabled by increasing alginate and CaCl2 concentrations, and (vi) encapsulation did not impair secretion of l-lactate as compared to free LBP.

CONCLUSIONS

This research demonstrates that polymer content and crosslinking extent modulate the performance of polymer-based LBP delivery systems, motivating research into the optimization of material properties for LBP delivery systems.