Encapsulation of Lactobacillus rhamnosus in Hyaluronic Acid-Based Hydrogel for Pathogen-Targeted Delivery to Ameliorate Enteritis

Incorporation of probiotics with pressure-sensitive pectin-fructooligosaccharide hydrogel for potential intestinal delivery

Probiotics and prebiotics serve as vital tools in managing gut microecology and enhancing immune responses. However, the effectiveness of non-encapsulated probiotics often diminishes during processing, storage, and transport to the gastrointestinal tract, especially at elevated temperatures. To address this challenge, a novel loading strategy for Lactobacillus reuteri DPC16 (L. reuteri) is proposed in this work, using pressure-sensitive high-methoxy pectin (HMP)/fructooligosaccharides (FOS) hydrogel. The HMP/FOS hydrogel melted at 600 MPa to form a sol. The resulting sol was mixed with L. reuteri immediately at ambient conditions, which underwent a sol-to-gel transition subsequently to form a composite hydrogel with a continuous porous structure. The resulting HMP/FOS@L. reuteri hydrogel achieved a loading concentration of viable bacteria at 109 CFU/mL. In vitro assessments reveal that the hydrogel demonstrates good biocompatibility and targeted release of probiotics within the intestine. Furthermore, the hydrogel substantially boosted the short-chain fatty acids levels and increased the amounts of acetic and isovaleric acids, respectively. This work underscores the unique advantages of employing a pressure-sensitive HMP/FOS hydrogel for loading and targeted delivery of probiotics and prebiotics to improve intestinal health.

Emerging Trends and Future Prospects of Peptide-Based Hydrogels: Revolutionizing Food Technology Applications

Peptide-based hydrogels (PHs) are versatile materials with considerable potential in food technology. Advances in synthesis techniques, such as self-assembly, click chemistry, enzymatic cross-linking, and co-assembly with polymers, have improved their production efficiency and scalability. Derived from natural amino acids, PHs are biocompatible, biodegradable, and responsive to environmental factors like pH and temperature. In food technology, encapsulation and controlled release of bioactive compounds enhance nutrient stability, flavor preservation, and bioavailability. PHs serve as texture modifiers, improve product consistency, and possess antimicrobial properties for food preservation by inhibiting spoilage and pathogens. Their biodegradability supports eco-friendly practices and sustainable packaging, including edible films and coatings that extend shelf life. Adjustable properties such as ionic strength make PHs adaptable to specific needs. PHs also show potential in developing advanced food equipment, including 3D printers and encapsulation systems, promoting efficiency and sustainability. This review emphasizes that PHs offer innovative, sustainable solutions to enhance food functionality, quality, and safety, with broad applications in food processing and preservation.

Nanocoating of quinoa protein and hyaluronic acid enhances viability and stability of Limosilactobacillus fermentum RC4 microcapsules

Nanocoating represents an effective strategy for creating a protective barrier on probiotic surfaces, preventing them from damage. Here, we developed HAQ microcapsules comprising Limosilactobacillus fermentum RC4, which were nanocoated with hyaluronic acid and quinoa protein. We characterized the stability and safety, and investigated the intermolecular forces and transcriptome to elucidate the mechanisms underlying the nanocoating. The encapsulation efficiency, survival rates following freeze drying, simulated oro-gastrointestinal conditions, and storage at 4 °C for 56 d were 10.32 %, 12.74 %, 7.56 %, and 14.56 % higher, respectively, than those of LF RC4 alone. The HAQ microcapsules demonstrated adhesion to Caco-2 cells and safely promoted proliferation in RAW 264.7 cells. Electrostatic and hydrophobic interactions emerged as the primary forces within the HAQ microcapsules, facilitating structural rearrangements of wall materials, promoting the ordered aggregation of quinoa protein, and enhancing the stability of microcapsules. Transcriptome analysis revealed that HAQ upregulated argF and carB involved in lysine and glutamic acid biosynthesis, while downregulating mraY and murG associated with carbohydrate biosynthesis. It is postulated that these regulatory effects may enhance bacterial metabolism and proliferation, thereby facilitating the exertion of functional properties such as adhesion. Our findings offer valuable insights into the development of highly active and stable probiotic freeze-dried powders.

Synthesis, characterization of thiolated hyaluronic acid and evaluation of its encapsulation effects on Limosilactobacillus reuteri HR7

Hyaluronic acid (HA) was thiol-modified by adding different concentrations of L-Cysteine (1 mmol, 2 mmol, 3 mmol, 4 mmol, 5 mmol and 6 mmol) and the resulting polymers (HA-SH) were characterized. The results of FTIR, 1H NMR, XRD, SEM and DSC all confirmed the success of thiol modification, accompanied by free thiol group content of 3169.51-3913.44 μmol/g. Sulfur element was only detected in HA-SH, accounting for 1.12 %-1.23 %. The Mw and particle size were decreased after thiol modification, representing a more uniform polysaccharide conformation, which was beneficial for the encapsulation of probiotics. Rheological analysis showed that the hydrogel prepared by HA displayed viscoelastic fluid properties, while the hydrogels prepared by HA-SH exhibited solid-like gel properties, indicating enhanced gelation properties after thiol modification. Subsequently, the hydrogels were applied to probiotics encapsulation to explore the effects on gastrointestinal tolerance. A higher encapsulation efficiency was observed in HA-SH hydrogel with enhanced gastrointestinal tolerance, increasing by 38.15 % on average. These results demonstrated that thiolation was a good strategy for polysaccharide modification and hydrogel formed by HA-SH was a more promising encapsulation and delivery system for probiotics compared with HA.

A Fungistatic Strategy Using a Shear-Thinning pH-Responsive CMCS-OHA-Lp/Lr Hydrogel for Vulvovaginal Candidiasis

Background: Vulvar vaginal candidiasis (VVC) is a type of vaginitis resulting from a Candida infection of the vaginal mucosa. Traditional treatments using antibiotics often lead to resistance and disrupt the vaginal microenvironment, causing ongoing problems for patients. In response to these challenges, this study introduces a multifunctional intelligent responsive probiotic hydrogel designed to modulate the vaginal microecological environment to combat Candida albicans infection. Methods: The innovative CMCS-OHA-Lp/Lr hydrogel was formulated using oxidized hyaluronic acid (OHA) and carboxymethyl chitosan (CMCS) as carriers, incorporating Lactobacillus plantarum (Lp) and Lactobacillus rhamnosus (Lr) as active components. Comprehensive characterization of the CMCS-OHA-Lp/Lr hydrogel revealed its chemical structure, rheological properties, rapid self-healing properties, gel degradation, and the release of lactobacilli in vitro. Results: The findings demonstrated that the hydrogel's cross-linking conferred significant physical properties. In addition, the in vitro release study of Lactobacillus showed that the cumulative release rates of Lp and Lr in the medium with pH 5.5 were 83.50 ± 2.70% and 73.31 ± 2.22%, which proved the pH-responsive release characteristics of probiotics in acidic vaginal environments. Furthermore, the storage activity of Lactobacillus indicated that the survival rates of the CMCS-OHA-Lp and CMCS-OHA-Lr hydrogels were 86.90 ± 0.20% and 85.50 ± 0.56%, respectively, proving that encapsulation within the hydrogels significantly enhanced the storage stability of probiotics. In vivo studies further confirmed that the hydrogel alleviated vulval edema symptoms and reduced C. albicans colonies in the vagina, thereby mitigating vaginal inflammation. Conclusions: In conclusion, this pH-responsive, self-healing, and shear-thinning hydrogel offers a promising approach for the clinical treatment of VVC and serves as an effective probiotic delivery vehicle.

Advances in the application of natural/synthetic hybrid hydrogels in tissue engineering and delivery systems: A comprehensive review

Hydrogels are widely used in biomedicine because of their excellent biocompatibility, physicochemical properties, three-dimensional cross-linked polymer networks capable of absorbing and retaining a large amount of water, and various excellent properties that can be endowed to hydrogels through modification and material integration. This review focuses on the polymer compositions and applications of natural/synthetic hybrid hydrogels. Firstly, the physical and chemical crosslinking mechanisms of hybrid hydrogels with different natural/synthetic polymer combinations were discussed in depth. In addition, polymers for the preparation of natural/synthetic hybrid hydrogels and their advantages and disadvantages are widely introduced, focusing on polysaccharides, proteins, natural aromatic polymers and common synthetic polymers. Finally, this review will focus on the applications of natural/synthetic hybrid hydrogels in tissue engineering and delivery systems. Such as bone tissue engineering, nerve tissue engineering and drug delivery.

Harnessing the polysaccharide production potential to optimize and expand the application of probiotics

Certain probiotic microorganisms can synthesize important bioproducts, including polysaccharides as components of cellular structure or extracellular matrix. Probiotic-derived polysaccharides have been widely applied in food, pharmaceutical, and medical fields due to their excellent properties and biological activities. The development of polysaccharide production potential has become a driving force for facilitating biotechnological applications of probiotics. Based on technical advances in synthetic biology, significant progress has recently been made in engineering probiotics with efficient biosynthesis of polysaccharides. Herein, this review summarizes probiotics chassis and genetic tools used for polysaccharide production. Then, probiotic polysaccharides and relevant biosynthesis mechanisms are also clearly described. Next, we introduce strategies for preparing high-yield, controllable molecular weight or non-native polysaccharides by adjusting metabolic pathways and integrating expression elements in probiotics. Finally, some prospective and well-established contributions of exogenous and in situ polysaccharides in probiotics' stability, bioactivity, and therapeutic effects are presented. Our viewpoints on advancing the efficient biomanufacturing of valuable biopolymers in probiotics and engineering probiotics with customized features are provided to exploit probiotics' industrial and biomedical applications.

Advances in the preparation, applications, challenges, and future trends of polysaccharide-based gels as food-grade delivery systems for probiotics: A review

Probiotics are highly regarded for their multiple functions, such as regulating gut health, enhancing the immune system, and preventing chronic diseases. However, their stability in harsh environments and targeted release remain significant challenges. Therefore, exploring effective protection and delivery strategies to ensure targeted release of probiotics is critically important. Polysaccharides, known for their non-toxicity, excellent biocompatibility, and superior biodegradability, show broad prospects in probiotic delivery by forming physical barriers to protect the probiotics. Particularly, polysaccharide-based gels (PBGs), with their unique "spider-web" like structure, capture and ensure the targeted release of probiotics, significantly enhancing their efficacy. This review discusses common polysaccharides used in PBG preparation, their classification and synthesis in food applications, and the advantages of PBGs as probiotic delivery systems. Despite their potential, challenges such as inconsistent gel properties and the need for improved stability remain. Future research should focus on developing novel PBG materials with higher biodegradability and mechanical strength, optimizing the physicochemical properties and cross-linking methods, as well as designing multilayered structures for more precise release control. Additionally, exploring the co-delivery of probiotics with prebiotics, active ingredients, or multi-strain systems could further enhance the efficacy of probiotic delivery.

Advancements of Biomacromolecular Hydrogel Applications in Food Nutrition and Health

Hydrogels exhibit remarkable degradability, biocompatibility and functionality, which position them as highly promising materials for applications within the food and pharmaceutical industries. Although many relevant studies on hydrogels have been reported in the chemical industry, materials, and other fields, there have been few reviews on their potential applications in food nutrition and human health. This study aims to address this gap by reviewing the functional properties of hydrogels and assessing their value in terms of food nutrition and human health. The use of hydrogels in preserving bioactive ingredients, food packaging and food distribution is delved into specifically in this review. Hydrogels can serve as cutting-edge materials for food packaging and delivery, ensuring the preservation of nutritional activity within food products, facilitating targeted delivery of bioactive compounds and regulating the digestion and absorption processes in the human body, thereby promoting human health. Moreover, hydrogels find applications in in vitro cell and tissue culture, human tissue repair, as well as chronic disease prevention and treatment. These broad applications have attracted great attention in the fields of human food nutrition and health. Ultimately, this paper serves as a valuable reference for further utilization and exploration of hydrogels in these respective fields.

Oral responsive delivery systems for probiotics targeting the intestinal tract

The increasing prevalence of health issues, driven by sedentary lifestyles and unhealthy diets in modern society, has led to a growing demand for natural dietary supplements to support overall health and well-being. Probiotic dietary supplements have garnered widespread recognition for their potential health benefits. However, their efficacy is often hindered by the hostile conditions of the gastrointestinal tract. To surmount this challenge, biomaterial-based microencapsulation techniques have been extensively employed to shield probiotics from the harsh environments of stomach acid and bile salts, facilitating their precise delivery to the colon for optimal nutritional effects. With consideration of the distinctive gastrointestinal tract milieu, probiotic delivery systems have been categorized into pH-responsive release, enzyme-responsive release, redox-responsive release and pressure-triggered release systems. These responsive delivery systems have not only demonstrated improved probiotic survival rates in the stomach, but also successful release in the intestines, facilitating enhanced adhesion and colonization of probiotics within the gut. Consequently, these responsive delivery systems contribute to the effectiveness of probiotic supplementation in intervening with gastrointestinal diseases. This review provides a comprehensive overview of the diverse oral responsive delivery systems tailored for probiotics targeting the intestinal tract. Furthermore, the review critically examines the limitations and future prospects of these approaches. This review offers valuable guidance for the effective delivery of probiotics to the intestinal tract, enhancing the potential of probiotics as dietary supplements to promote gastrointestinal health and well-being. © 2024 Society of Chemical Industry.

Accelerated infected wound healing by probiotic-based living microneedles with long-acting antibacterial effect

Delays in infected wound healing are usually a result of bacterial infection and local inflammation, which imposes a significant and often underappreciated burden on patients and society. Current therapies for chronic wound infection generally suffer from limited drug permeability and frequent drug administration, owing to the existence of a wound biofilm that acts as a barrier restricting the entry of various antibacterial drugs. Here, we report the design of a biocompatible probiotic-based microneedle (MN) patch that can rapidly deliver beneficial bacteria to wound tissues with improved delivery efficiency. The probiotic is capable of continuously producing antimicrobial substances by metabolizing introduced glycerol, thereby facilitating infected wound healing through long-acting antibacterial and anti-inflammatory effects. Additionally, the beneficial bacteria can remain highly viable (>80 %) inside MNs for as long as 60 days at 4 °C. In a mouse model of Staphylococcus aureus-infected wounds, a single administration of the MN patch exhibited superior antimicrobial efficiency and wound healing performance in comparison with the control groups, indicating great potential for accelerating infected wound closure. Further development of live probiotic-based MN patches may enable patients to better manage chronically infected wounds.

Intestinal Delivery of Probiotics: Materials, Strategies, and Applications

Probiotics with diverse and crucial properties and functions have attracted broad interest from many researchers, who adopt intestinal delivery of probiotics to modulate the gut microbiota. However, the major problems faced for the therapeutic applications of probiotics are the viability and colonization of probiotics during their processing, oral intake, and subsequent delivery to the gut. The challenges of simple oral delivery (stability, controllability, targeting, etc.) have greatly limited the use of probiotics in clinical therapies. Nanotechnology can endow the probiotics to be delivered to the intestine with improved survival rate and increased resistance to the adverse environment. Additionally, the progress in synthetic biology has created new opportunities for efficiently and purposefully designing and manipulating the probiotics. In this article, a brief overview of the types of probiotics for intestinal delivery, the current progress of different probiotic encapsulation strategies, including the chemical, physical, and genetic strategies and their combinations, and the emerging single-cell encapsulation strategies using nanocoating methods, is presented. The action mechanisms of probiotics that are responsible for eliciting beneficial effects are also briefly discussed. Finally, the therapeutic applications of engineered probiotics are discussed, and the future trends toward developing engineered probiotics with advanced features and improved health benefits are proposed.

A thiolated oxidized guar gum and sodium alginate dual-network microspheres with enhanced gastric acid resistance and mucoadhesion for delivery of probiotics

Probiotics offer numerous beneficial functions for human bodies, while the low survival rate under gastric acid and short retention time in the intestine are the major obstacles to their utilization. To address these issues, we designed a novel dual-network hydrogel microsphere that combines gastric acid resistance with enhanced mucoadhesion, aiming for the targeted delivery of probiotics. Thiolated oxidized guar gum (SOGG) was disulfide-linked to form the first network, and sodium alginate (SA) was cross-linked with Ca2+ to form the second network. Under the protection of the interpenetrating dual network microspheres, a much higher viability of Lactobacillus rhamnosus (LGG) (8.73 log CFU/mL) was achieved in simulated gastric fluid, compared to the zero-survival rate of free LGG. Mucoadhesion tests showed that the adhesion rate of SOGG/SA microspheres to the intestinal mucosa was 1.75 times higher than that of thiol-free microspheres. In vivo studies revealed that LGG-loaded microspheres significantly enhanced intestinal barrier function, remodeled the gut microbiome, and alleviated DSS-induced colitis in mice. Overall, SOGG/SA microspheres provide an effective strategy to the challenges of probiotic reduction in the stomach and rapid expulsion from the intestines, enhancing their health benefits.

Development, characterization and Lactobacillus plantarum encapsulating ability of novel C-phycocyanin-pectin-polyphenol based hydrogels

In this study, it was found that the enhancement in the viability of Lactobacillus plantarum under gastrointestinal conditions by encapsulating them within novel C-Phycocyanin-pectin based hydrogels (from 5.7 to 7.1 log/CFU). The hardness, the strength and the stability of the hydrogels increased when the protein concentration was increased. In addition, the addition of resveratrol (RES), and tannic acid (TA) could improve the hardness (from 595.4 to 608.3 and 637.0 g) and WHC (from 93.9 to 94.2 and 94.8 %) of the hydrogels. The addition of gallic acid (GA) enhanced the hardness (675.0 g) of the hydrogels, but the WHC (86.2 %) was decreased. During simulated gastrointestinal conditions and refrigerated storage, the addition of TA enhanced the viable bacteria counts (from 6.8 and 8.0 to 7.5 and 8.5 log/CFU) of Lactobacillus plantarum. Furthermore, TA and GA are completely encased by the protein-pectin gel as an amorphous state, while RA is only partially encased.

Shell-Core Microbeads Loaded with Probiotics: Influence of Lipid Melting Point on Probiotic Activity

Probiotics have many beneficial physiological activities, but the poor stability during storage and gastrointestinal digestion limits their application. Therefore, in this study, a novel type of shell-core microbead for loading probiotics was prepared through high-precision concentric drop formation technology using gelatin as the shell material and lipids as the core material. The microbeads have a regular spherical structure, uniform size, low moisture content (<4%) and high probiotic activity (>9.0 log CFU/g). Textural testing showed that the hardness of the medium-chain triglyceride microbeads (MCTBs), cocoa butter replacer microbeads (CBRBs) and hydrogenated palm oil microbeads (HPOBs) increased gradually (319.65, 623.54, 711.41 g), but their springiness decreased (67.7, 43.3, 34.0%). Importantly, lipids with higher melting points contributed to the enhanced stability of probiotics during simulated digestion and storage. The viable probiotic counts of the HCTBs, CBRBs and HPOBs after being stored at 25 °C for 12 months were 8.01, 8.44, and 8.51 log CFU/g, respectively. In the simulated in vitro digestion process, the HPOBs resisted the destructive effects of digestive enzymes and gastric acid on probiotics, with a reduction in the probiotic viability of less than 1.5 log CFU/g. This study can provide new ideas for the preparation of intestinal delivery probiotic foods.

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.

Novel delivery systems for controlled release of bacterial therapeutics

As more is learned about the benefits of microbes, their potential to prevent and treat disease is expanding. Microbial therapeutics are less burdensome and costly to produce than traditional molecular drugs, often with superior efficacy. Yet, as with most medicines, controlled dosing and delivery to the area of need remain key challenges for microbes. Advances in materials to control small-molecule delivery are expected to translate to microbes, enabling similar control with equivalent benefits. In this perspective, recent advances in living biotherapeutics are discussed within the context of new methods for their controlled release. The integration of these advances provides a roadmap for the design, synthesis, and analysis of controlled microbial therapeutic delivery systems.

Harnessing the power of probiotic strains in functional foods: nutritive, therapeutic, and next-generation challenges

Functional foods have become an essential element of the diet in developed nations, due to their health benefits and nutritive values. Such food products are only called functional if they, "In addition to basic nutrition, have valuable effects on one or multiple functions of the human body, thereby enhancing general and physical conditions and/or reducing the risk of disease progression". Functional foods are currently one of the most extensively researched areas in the food and nutrition sciences. They are fortified and improved food products. Presently, probiotics are regarded as the most significant and commonly used functional food product. Diverse probiotic food products and supplements are used according to the evidence that supports their strength, functionality, and recommended dosage. This review provides an overview of the current functional food market, with a particular focus on probiotic microorganisms as pivotal functional ingredients. It offers insights into current research endeavors and outlines potential future directions in the field.

Inorganic catalase-powered nanomotors with hyaluronic acid coating for pneumonia therapy

Clinical therapy for widespread infections caused by Streptococcus pneumoniae (S. pneumoniae), such as community-acquired pneumonia, is highly challenging. As an important bacterial toxin, hydrogen peroxide (H2O2) secreted by S. pneumoniae can suppress the host's immune system and cause more severe disease. To address this problem, a hyaluronic acid (HA)-coated inorganic catalase-driven Janus nanomotor was developed, which can cleverly utilize and decompose H2O2 to reduce the burden of bacterial infection, and have excellent drug loading capacity. HA coating prevents rapid leakage of loaded antibiotics and improves the biocompatibility of the nanomaterials. The Janus nanomotor converted H2O2 into oxygen (O2), gave itself the capacity to move actively, and encouraged widespread dispersion in the lesion site. Encouragingly, animal experiments demonstrated that the capability of the nanomotors to degrade H2O2 contributes to diminishing the proliferation of S. pneumoniae and lung tissue damage. This self-propelled drug delivery platform provides a new therapeutic strategy for infections with toxin-secreting bacteria.

Construction of Fu brick tea polysaccharide-cold plasma modified alginate microgels for probiotic delivery: Enhancing viability and colonization

Emerging food processing technologies provide broader avenues for enhancing probiotic delivery systems. In this study, the new Fu brick tea polysaccharide (FBTP) was extracted and combined with cold plasma-modified alginate nano-montmorillonite (AMT) to prepare microgels by ionic gelation to improve the viability of encapsulated Lactobacillus kefiranofaciens JKSP109. Results showed that cold plasma treatment for 3 min changed the surface charge of AMT biopolymer solution, and FBTP addition reduced the particle size to the lowest of 223 ± 5.50 nm. Morphological analysis showed that the AMT treated with cold plasma for 3 min and FBTP (C3AMT + FBTP) formed a dense microgel through electrostatic interaction, and the probiotics were randomly distributed in their internal polysaccharide network, as well as the interlayer and surrounding of nanoparticles. The probiotics immobilized in C3AMT + FBTP microgel exhibited the highest viability (8.48 ± 0.03 log CFU/g) and colonic colonization after exposure to simulated gastrointestinal conditions. In addition, the good antioxidant activity of FBTP reduced the loss of probiotic viability during storage, with only 2.58 log CFU/g decreased after 4 weeks. Therefore, such probiotic products enriched with natural bioactive ingredients can be developed as a potential functional food additive.

An inulin-based glycovesicle for pathogen-targeted drug delivery to ameliorate salmonellosis

The gut microbiota plays a significant role in the pathogenesis and remission of inflammatory bowel disease. However, conventional antibiotic therapies may alter microbial ecology and lead to dysbiosis of the gut microbiome, which greatly limits therapeutic efficacy. To address this challenge, novel nanomicelles that couple inulin with levofloxacin via disulfide bonds for the treatment of salmonellosis were developed in this study. Owing to their H2S-responsiveness, the nanomicelles can target the inflamed colon and rapidly release levofloxacin to selectively fight against enteric pathogens. Moreover, the embedded inulin can serve as prebiotic fiber to increase the amount of Bifidobacteria and Lactobacilli in mice with salmonellosis, thus maintaining the intestinal mechanical barrier and regulating the balance of the intestinal flora. Therefore, multifunctional nanomicelles had a better curative effect than pure levofloxacin on ameliorating inflammation in vivo. The pathogen-targeted glycovesicle represents a promising drug delivery platform to maximize the efficacy of antibacterial drugs for the treatment of inflammatory bowel disease.

Sensitive delivery systems and novel encapsulation technologies for live biotherapeutic products and probiotics

Live biotherapeutic product (LBP), a type of biological product, holds promise for the prevention or treatment of metabolic disease and pathogenic infection. Probiotics are live microorganisms that improve the intestinal microbial balance and beneficially affect the health of the host when ingested in sufficient numbers. These biological products possess the advantages of inhibition of pathogens, degradation of toxins, and modulation of immunity. The application of LBP and probiotic delivery systems has attracted great interest to researchers. The initial used technologies for LBP and probiotic encapsulation are traditional capsules and microcapsules. However, the stability and targeted delivery capability require further improved. The specific sensitive materials can greatly improve the delivery efficiency of LBPs and probiotics. The specific sensitive delivery systems show advantages over traditional ones due to their better properties of biocompatibility, biodegradability, innocuousness, and stability. Moreover, some new technologies, including layer-by-layer encapsulation, polyelectrolyte complexation, and electrohydrodynamic technology, show great potential in LBP and probiotic delivery. In this review, novel delivery systems and new technologies of LBPs and probiotics were presented, and the challenges and prospects were explored in specific sensitive materials for LBP and probiotic delivery.

Synthetic and biopolymers-based antimicrobial hybrid hydrogels: a focused review

The constantly accelerating occurrence of microbial infections and their antibiotic resistance has spurred advancement in the field of material sciences and has guided the development of novel materials with anti-bacterial properties. To address the clinical exigencies, the material of choice should be biodegradable, biocompatible, and able to offer prolonged antibacterial effects. As an attractive option, hydrogels have been explored globally as a potent biomaterial platform that can furnish essential antibacterial attributes owing to its three-dimensional (3D) hydrophilic polymeric network, adequate biocompatibility, and cellular adhesion. The current review focuses on the utilization of different antimicrobial hydrogels based on their sources (natural and synthetic). Further, the review also highlights the strategies for the generation of hydrogels with their advantages and disadvantages and their applications in different biomedical fields. Finally, the prospects in the development of hydrogels-based antimicrobial biomaterials are discussed along with some key challenges encountered during their development and clinical translation.

Microbial colony sequencing combined with metabolomics revealed the effects of chronic hexavalent chromium and nickel combined exposure on intestinal inflammation in mice

The pollution and toxic effects of hexavalent chromium [Cr(VI)] and divalent nickel [Ni(II)] have become worldwide public health issues. However, the potential detailed effects of chronic combined Cr(VI) and Ni exposure on colonic inflammation in mice have not been reported. In this study, 16S rDNA sequencing, metabolomics data analysis, qPCR and other related experimental techniques were used to comprehensively explore the mechanism of toxic damage and the inflammatory response of the colon in mice under the co-toxicity of chronic hexavalent chromium and nickel. The results showed that long-term exposure to Cr(VI) and/or Ni resulted in an imbalance of trace elements in the colon of mice with significant inflammatory infiltration of tissues. Moreover, Cr(VI) and/or Ni poisoning upregulated the expression levels of IL-6, IL-18, IL-1β, TNF-α, IFN-γ, JAK2 and STAT3 mRNA, and downregulated IL-10 mRNA, which was highly consistent with the trend in protein expression. Combined with multiomics analysis, Cr(VI) and/or Ni could change the α diversity and β diversity of the gut microbiota and induce significant differential changes in metabolites such as Pyroglu-Glu-Lys, Val-Asp-Arg, stearidonic acid, and 20-hydroxyarachidonic acid. They are also associated with disorders of important metabolic pathways such as lipid metabolism and amino acid metabolism. Correlation analysis revealed that there was a significant correlation between gut microbes and metabolites (P < 0.05). In summary, based on the advantages of comprehensive analysis of high-throughput sequencing sets, these results suggest that chronic exposure to Cr(VI) and Ni in combination can cause microbial flora imbalances, induce metabolic disorders, and subsequently cause colonic damage in mice. These data provide new insights into the toxicology and molecular mechanisms of Cr(VI) and Ni.

Nanozyme-Enhanced Probiotic Spores Regulate the Intestinal Microenvironment for Targeted Acute Gastroenteritis Therapy

Antibiotic therapeutics to combat intestinal pathogen infections often exacerbate microbiota dysbiosis and impair mucosal barrier functions. Probiotics are promising strategies, because they inhibit pathogen colonization and improve intestinal microbiota imbalance. Nevertheless, their limited targeting ability and susceptibility to oxidative stress have hindered their therapeutic potential. To tackle these challenges, Ces3 is synthesized by in situ growth of CeO2 nanozymes with positive charges on probiotic spores, facilitating electrostatic interactions with negatively charged pathogens and possessing a high reactive oxygen species (ROS) scavenging activity. Importantly, Ces3 can resist the harsh environment of the gastrointestinal tract. In mice with S. Typhimurium-infected acute gastroenteritis, Ces3 shows potent anti-S. Typhimurium activity, thereby alleviating the dissemination of S. Typhimurium into other organs. Additionally, owing to its O2 deprivation capacity, Ces3 promotes the proliferation of anaerobic probiotics, reshaping a healthy intestinal microbiota. This work demonstrates the promise of combining antibacterial, anti-inflammatory, and O2 content regulation properties for acute gastroenteritis therapy.

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 Nanomedicine: Challenges and Opportunities

Compared to injection administration, oral administration is free of discomfort, wound infection, and complications and has a higher compliance rate for patients with diverse diseases. However, oral administration reduces the bioavailability of medicines, especially biologics (e.g., peptides, proteins, and antibodies), due to harsh gastrointestinal biological barriers. In this context, the development and prosperity of nanotechnology have helped improve the bioactivity and oral availability of oral medicines. On this basis, first, the biological barriers to oral administration are discussed, and then oral nanomedicine based on organic and inorganic nanomaterials and their biomedical applications in diverse diseases are reviewed. Finally, the challenges and potential opportunities in the future development of oral nanomedicine, which may provide a vital reference for the eventual clinical transformation and standardized production of oral nanomedicine, are put forward.

Acetolactate Decarboxylase as an Important Regulator of Intracellular Acidification, Morphological Features, and Antagonism Properties in the Probiotic Lactobacillus reuteri

SCORE

This study identifies the coding gene (aldB) of acetolactate decarboxylase (ALDC) as an important regulatory gene of the intracellular pH in Lactobacillus reuteri (L. reuteri), uncovering the important role of ALDC in regulating intracellular pH, morphological features, and antagonism properties in the probiotic organism L. reuteri.

METHODS AND RESULTS

The aldB mutant (ΔaldB) of L. reuteri is established using the homologous recombination method. Compare to the wild-type (WT) strain, the ΔaldB strain shows a smaller body size, grows more slowly, and contains more acid in the cell cytoplasm. The survival rate of the ΔaldB strain is much lower in low pH and simulated gastric fluid (SGF) than that of the WT strain, but higher in simulated intestinal fluid (SIF). The antagonism test demonstrates the ΔaldB strain can inhibit Listeria monocytogenes (L. monocytogenes) and Salmonella more effectively than the WT strain. Additionally, there is a dramatic decrease in the adhesion rate of Salmonella to Caco-2 and HT-29 cells in the presence of the ΔaldB strain compared to the WT strain. Simultaneously analyze, the auto-aggregation, co-aggregation, cell surface hydrophobicity (CSH), hemolytic, temperature, NaCl, oxidative stress, and antibiotic susceptibility of the ΔaldB strain are consistent with the features of probiotics.

CONCLUSION

This study highlights that the aldB gene plays a significant role in the growth and antibacterial properties of L. reuteri.

Photo-crosslinking modified sodium alginate hydrogel for targeting delivery potential by NO response

In recent years, the incidence of inflammatory bowel disease has gradually increased. Traditional drugs can reduce inflammation, but cannot be targeting released and often require the coordination with delivery systems. However, a good targeting performance delivery system is still scarce currently. Inflammation can trigger oxidative stress, producing large amounts of oxides such as nitric oxide (NO). Based on this, the present experiment innovatively designed a hydrogel delivery system with NO response that could be inflammation targeting. The hydrogel is composed of sodium alginate modified with glycerol methacrylate, crosslinked with NO response agent by photo-crosslinking method, which have low swelling (37 %) and good mechanical properties with a stable structure even at 55 °C. The results of in vitro digestion also indicated that the hydrogel had a certain tolerance to gastrointestinal digestion. And in the NO environment, it was interestingly found that the structure and mechanical properties of the hydrogels changed significantly. Moreover, hydrogels have good biocompatibility, which ensures their safe use in vivo. In conclusion, this NO-responsive-based delivery system is feasible and provides a new approach for drugs and active factors targeting delivery in the future.

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.

Preparation of Polysaccharide-Protein Hydrogels with an Ultrafast Self-Healing Property as a Superior Oral Delivery System of Probiotics

Oral administration of probiotic supplements can effectively regulate intestinal disorders. However, harsh gastrointestinal conditions greatly limit the bioavailability of probiotics. In this work, biomass-derived polysaccharide-protein hydrogels (Dex-sBSA hydrogels) were constructed as an oral probiotic delivery system. The hydrogel encapsulation significantly promoted the growth and proliferation of probiotics and protected them from gastric acid, bile salts, reactive oxygen species, and antibiotics. In vivo experiments demonstrated that the hydrogel encapsulation significantly enhanced the bioavailability of probiotics, of which the cell number in the intestine, colon, and cecum was 35 times, 8 times, and 203 times higher than the free one, respectively. Attributed to the superior ultrafast self-healing property, the Dex-sBSA hydrogel successfully prevented the probiotics from quick elimination and prolonged the retention time in the gut, providing great possibilities for colonization and proliferation. These results clearly indicate the great potential of the Dex-sBSA hydrogel as a superior oral delivery system for probiotics.

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.

Phycocyanin/lysozyme nanocomplexes to stabilize Pickering emulsions for fucoxanthin encapsulation

Food-grade Pickering emulsions with plant proteins have attracted increasing interest in recent years. In this work, we report a type of phycocyanin (PC) electrostatic nanocomplex fabricated following a complexation between PC and lysozyme (Lys). The aim was to investigate toward investigating the performance of phycocyanin-Lysozyme (PC-Lys) nanocomplexes in stabilizing Pickering emulsions and protecting fucoxanthin (FX) from degradation. The properties of the PC-Lys nanocomplexes were characterized by 1H nuclear magnetic resonance (NMR) spectroscopy and three-phase contact angle. Using PC-Lys nanocomplexes as emulsifiers, Pickering emulsions were successfully prepared. Pickering emulsions stabilized by PC-Lys nanocomplexes generated a tight three-dimensional network structure, which increased the memory modulus and viscoelasticity of the emulsion. Furthermore, the produced Pickering emulsions considerably increased the chemical stability and bioavailability of FX. Overall, our study showed that PC-Lys nanocomplexes have the potential for use in Pickering emulsion construction with enhanced protective effects on loaded lipophilic ingredients.

Armored probiotics for oral delivery

As a kind of intestinal flora regulator, probiotics show great potential in the treatment of many diseases. However, orally delivered probiotics are often vulnerable to unfriendly gastrointestinal environments, resulting in a low survival rate and decreased therapeutic efficacy. Decorating or encapsulating probiotics with functional biomaterials has become a facile yet useful strategy, and probiotics can be given different functions by wearing different armors. This review systematically discusses the challenges faced by oral probiotics and the research progress of armored probiotics delivery systems. We focus on how various functional armors help probiotics overcome different obstacles and achieve efficient delivery. We also introduce the applications of armor probiotics in disease treatment and analyze the future trends of developing advanced probiotics-based therapies.

Biomaterials and Encapsulation Techniques for Probiotics: Current Status and Future Prospects in Biomedical Applications

Probiotics have garnered significant attention in recent years due to their potential advantages in diverse biomedical applications, such as acting as antimicrobial agents, aiding in tissue repair, and treating diseases. These live bacteria must exist in appropriate quantities and precise locations to exert beneficial effects. However, their viability and activity can be significantly impacted by the surrounding tissue, posing a challenge to maintain their stability in the target location for an extended duration. To counter this, researchers have formulated various strategies that enhance the activity and stability of probiotics by encapsulating them within biomaterials. This approach enables site-specific release, overcoming technical impediments encountered during the processing and application of probiotics. A range of materials can be utilized for encapsulating probiotics, and several methods can be employed for this encapsulation process. This article reviews the recent advancements in probiotics encapsulated within biomaterials, examining the materials, methods, and effects of encapsulation. It also provides an overview of the hurdles faced by currently available biomaterial-based probiotic capsules and suggests potential future research directions in this field. Despite the progress achieved to date, numerous challenges persist, such as the necessity for developing efficient, reproducible encapsulation methods that maintain the viability and activity of probiotics. Furthermore, there is a need to design more robust and targeted delivery vehicles.

Reductase-Labile Peptidic Supramolecular Hydrogels Aided in Oral Delivery of Probiotics

Oral delivery of probiotics has been a promising method for treatment of inflammatory bowel diseases (IBDs). However, probiotics always suffer from substantial loss of viability due to the harsh gastrointestinal conditions, especially the highly acidic environment in the stomach and bile salts in the intestine. In addition, to overcome the challenging conditions, an ideal delivery of probiotics requires the on-demand release of probiotics upon environmental response. Herein, a novel nitroreductase (NTR) labile peptidic hydrogel based on supramolecular self-assembly is demonstrated. The efficient encapsulation of typical probiotic Escherichia coli Nissle 1917 (EcN) into supramolecular assemblies yielded a probiotic-loaded hydrogel (EcN@Gel). Such a hydrogel adequately protected EcN to improve its viability against harsh acid and bile salt environments during oral delivery. The upregulated NTR in the intestinal tract triggered the disassembly of the hydrogel and accomplished the controlled release of EcN locally. In ulcerative colitis (UC)-bearing mice, EcN@Gel showed significantly enhanced therapeutic efficacy by downregulating proinflammatory cytokines and repairing the intestinal barrier. Moreover, EcN@Gel remolded the gut microbiome by increasing the diversity and abundance of indigenous probiotics, contributing to ameliorated therapies of IBDs. The NTR-labile hydrogel provided a promising platform for the on-demand delivery of probiotics into the intestinal tract.

A probiotic nanozyme hydrogel regulates vaginal microenvironment for Candida vaginitis therapy

Molecular therapeutics are limited for Candida vaginitis because they damage normal cells and tissues of vagina, aggravating the imbalance of vaginal microbiota and increasing the recurrence. To tackle this limitation, through the combination of peroxidase-like rGO@FeS₂ nanozymes [reduced graphene oxide (rGO)] with Lactobacillus-produced lactic acid and H₂O₂, a responsive hyaluronic acid (HA) hydrogel rGO@FeS₂/Lactobacillus@HA (FeLab) is developed. FeLab has simultaneous anti-Candida albicans and vaginal microbiota-modulating activities. In particular, the hydroxyl radical produced from rGO@FeS₂ nanozymes and Lactobacillus kills C. albicans isolated from clinical specimens without affecting Lactobacillus. In mice with Candida vaginitis, FeLab has obvious anti-C. albicans activity but hardly damages vaginal mucosa cells, which is beneficial to vaginal mucosa repair. Moreover, a higher proportion of Firmicutes (especially Lactobacillus) and a decrease in Proteobacteria reshape a healthy vaginal microbiota to reduce the recurrence. These results provide a combined therapeutic of nanozymes and probiotics with translational promise for Candida vaginitis therapy.

Polysaccharides, proteins, and their complex as microencapsulation carriers for delivery of probiotics: A review on carrier types and encapsulation techniques

Probiotics provide several benefits for humans, including restoring the balance of gut bacteria, boosting the immune system, and aiding in the management of certain conditions such as irritable bowel syndrome and lactose intolerance. However, the viability of probiotics may undergo a significant reduction during food storage and gastrointestinal transit, potentially hindering the realization of their health benefits. Microencapsulation techniques have been recognized as an effective way to improve the stability of probiotics during processing and storage and allow for their localization and slow release in intestine. Although, numerous techniques have been employed for the encapsulation of probiotics, the encapsulation techniques itself and carrier types are the main factors affecting the encapsulate effect. This work summarizes the applications of commonly used polysaccharides (alginate, starch, and chitosan), proteins (whey protein isolate, soy protein isolate, and zein) and its complex as the probiotics encapsulation materials; evaluates the evolutions in microencapsulation technologies and coating materials for probiotics, discusses their benefits and limitations, and provides directions for future research to improve targeted release of beneficial additives as well as microencapsulation techniques. This study provides a comprehensive reference for current knowledge pertaining to microencapsulation in probiotics processing and suggestions for best practices gleaned from the literature.

Construction of Probiotic Double-Layered Multinucleated Microcapsules Based on Sulfhydryl-Modified Carboxymethyl Cellulose Sodium for Increased Intestinal Adhesion of Probiotics and Therapy for Intestinal Inflammation Induced by Escherichia coli O157:H7

The decreased number of viable bacteria and the ability of Bifidobacterium to adhere to and colonize the gut in the gastrointestinal environment greatly limit their efficacy. To solve this problem, thiolated carboxymethyl cellulose sodium (CMC) probiotic double-layered multinucleated microcapsules with Bifidobacterium adolescentis FS2-3 in the inner layer and Bacillus subtilis SN15-2 embedded in the outer layers were designed. First, the viable counts and release rates of microcapsules were examined by in vitro simulated digestion assays, and it was found that microcapsules were better protected from gastrointestinal digestion than the controls. Compared with free Bifidobacterium strains, double-layered multinucleated microcapsules have higher viable bacterial survival rates and storage stability. Second, through in vitro rheology, tensile tests, isotherm titration calorimetry, and adhesion tests, it was observed that thiolated CMC could enhance the strong interaction of Bifidobacterium with intestinal mucus and significantly promote the proliferation and growth of probiotics. Finally, double-layered multinucleated microcapsules containing B. adolescentis FS2-3 and B. subtilis SN15-2 modified with sulfhydryl-modified CMC were studied in the intestine. Alleviation of Escherichia coli O157:H7 induced intestinal inflammation. The results showed that microencapsulation could significantly increase the colon content of Bifidobacterium, relieve intestinal inflammation symptoms in mice with bacterial enteritis, and repair the intestinal microbiota disorder caused by inflammation. The probiotic double-layered multinucleated microcapsules prepared in this study can improve the survival rate of probiotics and promote proliferation, adhesion, and colonization of probiotics.

Bacteria-Induced Colloidal Encapsulation for Probiotic Oral Delivery

Probiotic oral delivery has crucial implications in biomedical engineering, but its oral bioavailability remains unsatisfactory because of the limited survival and colonization of probiotics in the harsh gastrointestinal tract. Here, a bacteria-induced encapsulation strategy is achieved by assembling metastable colloids to enhance the oral bioavailability of probiotics. The colloids (NTc) composed of amino-modified poly-β-cyclodextrin and tannic acid are formed based on the balance of host-guest interaction-driven attraction and electrostatic repulsion between colloids. Negatively charged probiotics electrostatically attract positively charged NTc to break the balance and induce further assembly surrounding the probiotics. Through a facile one-step mixing, 97% of bacteria are rapidly encapsulated into NTc shells within 10 s, with a high utilization rate of feeding colloids of 91%. More importantly, we show that the compact, thick, and positively charged NTc shells synergistically endow the encapsulated probiotics with strong resistance against simulated gastric fluid with an excellent survival rate of up to 19%, 7500 times superior to the commercial enteric material L100. Moreover, owing to the dynamically noncovalent and self-adaptive nature of host-guest interactions, NTc shells support the proliferation of the encapsulated EcN comparable with that of the naked EcN. In vitro and in vivo experiments also confirm that the NTc-encapsulated probiotics possess durable intestinal adhesion, continuous proliferation activity, enhanced oral bioavailability, good oral biosafety, and excellent therapeutic efficacy in a colitis mouse model. This facile bacteria-induced colloidal encapsulation strategy may extend to various microbes as oral bioagents for treating various diseases.

Lactobacillus paracasei TK1501 fermented soybeans alleviate dextran sulfate sodium-induced colitis by regulating intestinal cell function

BACKGROUND

Probiotic food provide health benefits by regulating intestinal floras via live bacteria, but the shelf life is short and the preservation condition is demanding due to the bacteria being fragile. Owing to these problems, we have tried to find a fermented food that is helpful for inflammatory bowel disease treatment but independent of live bacteria. In addition, the mechanisms of fermented food were investigated. Dextran sulfate sodium was used to model inflammatory bowel disease in mice, and Lactobacillus paracasei TK1501 fermented soybeans and their metabolites were used to treat inflammatory bowel disease.

RESULTS

In this study, TK1501 fermented soybean alleviated colitis. However, the efficacy was associated with bacterial metabolites but not live or dead bacteria. Compositional analysis of soybean before and after fermentation shows that soy carbohydrates were used for bacteria growth and produced functional substances. Further, we display the main active ingredient was lipoteichoic acid and peptidoglycan, because lipoteichoic acid reduced the colonic macrophage and peptidoglycan may increase the mucin-2 expression. A cell experiment displayed that lipoteichoic acid could enhance the phagocytosis of macrophages.

CONCLUSION

In general, TK1501 fermented soybean alleviating colitis is dependent on metabolites of TK1501, particularly lipoteichoic acid and peptidoglycan. The fermented food may have a long shelf life and lax storage condition. © 2023 Society of Chemical Industry.

Colon-targeted bacterial hydrogel for tumor vascular normalization and improved chemotherapy

The endogenous H₂S plays an important role in the occurrence and development of colon cancer, and is related to the abnormal blood vessels. Here, we reported on a sulfhydryl hyaluronid-based hydrogel (HA-SH) synthesized by amide reaction and further obtained a bacterial hydrogel by loading Thiobacillus denitrificans to the hydrogel for targeting adhesion to the colon. It was found that the loaded bacteria in HA-SH hydrogel can scavenge excess H₂S in colon cancer, then promote tumor vascular normalization and improve the delivery of chemotherapy drug CPT to inhibit tumor progression. Both in vivo and in vitro experiments show that the self-crosslinked bacterial hydrogel has satisfactory effects in inhibiting tumor progression and promoting tumor vascular normalization in colon cancer. This study presents an efficient method to target the colon and consume overexpressed H₂S in colon cancer to inhabit tumor progression, providing a new way for oral drug treatment of colon cancer.

Potential applications of drug delivery technologies against radiation enteritis

INTRODUCTION

The incidence of abdominal tumors, such as colorectal and prostate cancers, continually increases. Radiation therapy is widely applied in the clinical treatment of patients with abdominal/pelvic cancers, but it often unfortunately causes radiation enteritis (RE) involving the intestine, colon, and rectum. However, there is a lack of suitable treatment options for effective prevention and treatment of RE.

AREAS COVERED

Conventional clinical drugs for preventing and treating RE are usually applied by enemas and oral administration. Innovative gut-targeted drug delivery systems including hydrogels, microspheres, and nanoparticles are proposed to improve the prevention and curation of RE.

EXPERT OPINION

The prevention and treatment of RE have not attracted sufficient attention in the clinical practice, especially compared to the treatment of tumors, although RE takes patients great pains. Drug delivery to the pathological sites of RE is a huge challenge. The short retention and weak targeting of conventional drug delivery systems affect the therapeutic efficiency of anti-RE drugs. Novel drug delivery systems including hydrogels, microspheres, and nanoparticles can allow drugs long-term retention in the gut and targeting the inflammation sites to alleviate radiation-induced injury.

Multifunctional hydrogels based on chitosan, hyaluronic acid and other biological macromolecules for the treatment of inflammatory bowel disease: A review

Hydrogel is a three-dimensional network polymer material rich in water. It is widely used in the biomedical field because of its unique physical and chemical properties and good biocompatibility. In recent years, the incidence of inflammatory bowel disease (IBD) has gradually increased, and the disadvantages caused by traditional drug treatment of IBD have emerged. Therefore, there is an urgent need for new treatments to alleviate IBD. Hydrogel has become a potential therapeutic platform. However, there is a lack of comprehensive review of functional hydrogels for IBD treatment. This paper first summarizes the pathological changes in IBD sites. Then, the action mechanisms of hydrogels prepared from chitosan, sodium alginate, hyaluronic acid, functionalized polyethylene glycol, cellulose, pectin, and γ-polyglutamic acid on IBD were described from aspects of drug delivery, peptide and protein delivery, biologic therapies, loading probiotics, etc. In addition, the advanced functions of IBD treatment hydrogels were summarized, with emphasis on adhesion, synergistic therapy, pH sensitivity, particle size, and temperature sensitivity. Finally, the future development direction of IBD treatment hydrogels has been prospected.

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.

Stable colonization of Akkermansia muciniphila educates host intestinal microecology and immunity to battle against inflammatory intestinal diseases

Gut microbial preparations are widely used in treating intestinal diseases but show mixed success. In this study, we found that the therapeutic efficacy of A. muciniphila for dextran sodium sulfate (DSS)-induced colitis as well as intestinal radiation toxicity was ~50%, and mice experiencing a positive prognosis harbored a high frequency of A. muciniphila in the gastrointestinal (GI) tract. Stable GI colonization of A. muciniphila elicited more profound shifts in the gut microbial community structure of hosts. Coexisting with A. muciniphila facilitated proliferation and reprogrammed the gene expression profile of Lactobacillus murinus, a classic probiotic that overtly responded to A. muciniphila addition in a time-dependent manner. Then, a magnetic-drove, mannose-loaded nanophase material was designed and linked to the surface of A. muciniphila. The modified A. muciniphila exhibited enhancements in inflammation targeting and intestinal colonization under an external magnetic field, elevating the positive-response rate and therapeutic efficacy against intestinal diseases. However, the unlinked cocktail containing A. muciniphila and the delivery system only induced negligible improvement of therapeutic efficacy. Importantly, heat-inactivated A. muciniphila lost therapeutic effects on DSS-induced colitis and was even retained in the GI tract for a long time. Further investigations revealed that the modified A. muciniphila was able to drive M2 macrophage polarization by upregulating the protein level of IL-4 at inflammatory loci. Together, our findings demonstrate that stable colonization of live A. muciniphila at lesion sites is essential for its anti-inflammatory function.

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.

Polysaccharide-based hydrogels for drug delivery and wound management: a review

INTRODUCTION

Polysaccharide-based hydrogels (PBHs) offer several advantages over their synthetic counterparts. Their natural origin contributes to their nontoxicity, high biocompatibility, and in vivo biodegradability. Their properties can be tuned finely to obtain hydrogels with desired mechanical, structural, and chemical properties.

AREAS COVERED

Such versatile characteristics have potentiated the use of PBHs for the delivery of drugs, vaccines, protein and peptide therapeutics, genes, cells, probiotics, bacteriophages, and other therapeutic agents. Recent advances in hydrogel-based formulations such as nanogels, microgels, microneedles, hydrogel beads, nanocarrier-loaded hydrogels, and complexation hydrogels have enabled the precise delivery of a wide range of therapeutics. This review aims to give a holistic overview of hydrogels in the delivery of a variety of therapeutics through different routes.

EXPERT OPINION

PBHs have been used to enable the oral delivery of vaccines and other biologicals, thereby allowing self-administration of life-saving vaccines during public health emergencies. There is a lack of commercialized wound dressings for the treatment of chronic wounds. PBH-based wound dressings, especially those based on chitosan and loaded with actives and growth factors, have the potential to help in the long-term treatment of such wounds. Recent developments in the 3D printing of hydrogels can enable the quick and large-scale production of drug-loaded hydrogels.