Hydrogel Encapsulation of Lactobacillus casei by Block Charge Modified Pectin and Improved Gastric and Storage Stability

Physicochemical, structural and functional properties of low methoxyl pectin‑iron (III) complex and its effect on rats with iron deficiency anemia

Iron deficiency anemia (IDA) is the most common nutritional disease worldwide. In this study, a low methoxyl pectin (LMP)‑iron(III) complex was prepared. The physicochemical and structural properties were characterized by HPSEC, HPIC, CV, FTIR, 1H NMR, XRD, SEM and CD. The results showed that iron increased the molecular weight of the LMP‑iron(III) from 11.50 ± 0.32 to 12.70 ± 0.45 kDa and improved its crystallinity. Moreover, the findings demonstrated that -OH and -COOH groups in LMP coordinate with Fe3+ to form β-FeOOH. The water-holding capacity, emulsion stability, and antioxidant activities of the LMP‑iron(III) were lower than those of LMP. Furthermore, the therapeutic effects of LMP‑iron(III) on IDA were investigated in rats. Following LMP‑iron(III) supplementation, compared with the model group, the administration of LMP‑iron(III) significantly increased the body weight, hemoglobin concentration, and serum iron concentration as well as decreased free erythrocyte protoporphyrin concentration. Therefore, the LMP‑iron(III) can potentially treat IDA in rats experiments, providing a theoretical basis for the development of a promising iron supplement.

Integrated oral microgel system ameliorates renal fibrosis by hitchhiking co-delivery and targeted gut flora modulation

BACKGROUND

Renal fibrosis is a progressive process associated with chronic kidney disease (CKD), contributing to impaired kidney function. Active constituents in traditional Chinese herbs, such as emodin (EMO) and asiatic acid (AA), exhibit potent anti-fibrotic properties. However, the oral administration of EMO and AA results in low bioavailability and limited kidney accumulation. Additionally, while oral probiotics have been accepted for CKD treatment through gut microbiota modulation, a significant challenge lies in ensuring their viability upon administration. Therefore, our study aims to address both renal fibrosis and gut microbiota imbalance through innovative co-delivery strategies.

RESULTS

In this study, we developed yeast cell wall particles (YCWPs) encapsulating EMO and AA self-assembled nanoparticles (NPYs) and embedded them, along with Lactobacillus casei Zhang, in chitosan/sodium alginate (CS/SA) microgels. The developed microgels showed significant controlled release properties for the loaded NPYs and prolonged the retention time of Lactobacillus casei Zhang (L. casei Zhang) in the intestine. Furthermore, in vivo biodistribution showed that the microgel-carried NPYs significantly accumulated in the obstructed kidneys of rats, thereby substantially increasing the accumulation of EMO and AA in the impaired kidneys. More importantly, through hitchhiking delivery based on yeast cell wall and positive modulation of gut microbiota, our microgels with this synergistic strategy of therapeutic and modulatory interactions could regulate the TGF-β/Smad signaling pathway and thus effectively ameliorate renal fibrosis in unilateral ureteral obstruction (UUO) rats.

CONCLUSION

In conclusion, our work provides a new strategy for the treatment of renal fibrosis based on hitchhiking co-delivery of nanodrugs and probiotics to achieve synergistic effects of disease treatment and targeted gut flora modulation.

Recent progress and treatment strategy of pectin polysaccharide based tissue engineering scaffolds in cancer therapy, wound healing and cartilage regeneration

Natural polymers and its mixtures in the form of films, sponges and hydrogels are playing a major role in tissue engineering and regenerative medicine. Hydrogels have been extensively investigated as standalone materials for drug delivery purposes as they enable effective encapsulation and sustained release of drugs. Biopolymers are widely utilised in the fabrication of hydrogels due to their safety, biocompatibility, low toxicity, and regulated breakdown by human enzymes. Among all the biopolymers, polysaccharide-based polymer is well suited to overcome the limitations of traditional wound dressing materials. Pectin is a polysaccharide which can be extracted from different plant sources and is used in various pharmaceutical and biomedical applications including cartilage regeneration. Pectin itself cannot be employed as scaffolds for tissue engineering since it decomposes quickly. This article discusses recent research and developments on pectin polysaccharide, including its types, origins, applications, and potential demands for use in AI-mediated scaffolds. It also covers the materials-design process, strategy for implementation to material selection and fabrication methods for evaluation. Finally, we discuss unmet requirements and current obstacles in the development of optimal materials for wound healing and bone-tissue regeneration, as well as emerging strategies in the field.

Advances in polysaccharides for probiotic delivery: Properties, methods, and applications

Probiotics are essential to improve the health of the host, whereas maintaining the viability of probiotics in harsh environments remains a challenge. Polysaccharides have non-toxicity, excellent biocompatibility, and outstanding biodegradability, which can protect probiotics by forming a physical barrier and show a promising prospect for probiotic delivery. In this review, we summarize polysaccharides commonly used for probiotic microencapsulation and introduce the microencapsulation technologies, including extrusion, emulsion, spray drying, freeze drying, and electrohydrodynamics. We discuss strategies for better protection of probiotics and introduce the applications of polysaccharides-encapsulated probiotics in functional food, oral formulation, and animal feed. Finally, we propose the challenges of polysaccharides-based delivery systems in industrial production and application. This review will help provide insight into the advances and challenges of polysaccharides in probiotic delivery.

Controlled release of Lactiplantibacillus plantarum by colon-targeted adhesive pectin microspheres: Effects of pectin methyl esterification degrees

The aim of this study is to report the preparation of pectin microspheres by varying degrees of methyl esterification (DM) cross-linked with divalent cationic calcium to encapsulate Lactiplantibacillus plantarum STB1 and L. plantarum LJ1, respectively. Scanning electron microscopy revealed the compact and smooth surface of pectin of DM 28 %, and the stochastic distribution of L. plantarum throughout the gel reticulation. And the pectin of DM 28 % considerably increased probiotics tolerance after continuous exposure to stimulated gastrointestinal tract conditions, with viable counts exceeding 10⁹ CFU/mL. This data indicated that low methoxy-esterification pectin was more efficient to improve the targeted delivery of probiotics in GIT. Additionally, the controlled release of microspheres was dependent on various pH levels. At pH 7.4, the release rates of L. plantarum STB1 and L. plantarum LJ1 reached up to 97.63 % and 95.33 %, respectively. Finally, the Caco-2 cell adhesion model was used to evaluate the cell adhesion rate after encapsulation, which exhibited better adhesion at DM of 60 %.

Apple-derived 3D scaffold for improving gastrointestinal viability and in-situ growth of probiotics

This study develops a novel low-cost microbial delivery system by transforming common food materials such as apple tissue into a 3D scaffold. Apple tissue scaffold was constructed by decellularization of intact tissue using a minimal amount of sodium dodecyl sulfate (0.5 % w/v). Vacuum-assisted infusion of model probiotic Lactobacillus cells led to a high encapsulation yield of probiotic cells (10¹⁰ CFU/g of scaffold) in 3D scaffolds on a wet basis. The bio-polymer coated 3D scaffolds with infused cells significantly enhanced the survivability of infused probiotic cells during simulated gastric and intestinal digestions. In addition, imaging and plate counting results validate the growth of the infused cells in the 3D scaffold after 1-2 days of fermentation in MRS media, while cells without infusion in the scaffold had limited attachment with the intact apple tissue. Overall, these results highlight the potential of the apple tissue-derived 3D scaffold to deliver probiotic cells and include the biochemical compositions to support the growth of delivered microbial cells in the colon.

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.

Effect of Microencapsulation Techniques on the Stress Resistance and Biological Activity of Bovine Lactoferricin-Lactoferrampin-Encoding Lactobacillus reuteri

Bovine lactoferricin-lactoferrampin-encoding Lactobacillus reuteri (LR-LFCA) has been found to benefit its host by strengthening its intestinal barrier. However, several questions remain open concerning genetically engineered strains maintaining long-term biological activity at room temperature. In addition, probiotics are vulnerable to harsh conditions in the gut, such as acidity and alkalinity, and bile salts. Microencapsulation is a technique to entrap probiotic bacteria into gastro-resistant polymers to carry them directly to the intestine. We selected nine kinds of wall material combinations to encapsulate LR-LFCA by spray drying microencapsulation. The storage stability, microstructural morphology, biological activity, and simulated digestion in vivo or in vitro of the microencapsulated LR-LFCA were further evaluated. The results showed that LR-LFCA had the highest survival rate when microcapsules were prepared using a wall material mixture (skim milk, sodium glutamate, polyvinylpyrrolidone, maltodextrin, and gelatin). Microencapsulated LR-LFCA increased the stress resistance capacity and colonization abilities. In the present study, we have identified a suitable wall material formulation for spray-dried microencapsulation of genetically engineered probiotic products, which would facilitate their storage and transport.

The encapsulation strategy to improve the survival of probiotics for food application: From rough multicellular to single-cell surface engineering and microbial mediation

The application of probiotics is limited by the loss of survival due to food processing, storage, and gastrointestinal tract. Encapsulation is a key technology for overcoming these challenges. The review focuses on the latest progress in probiotic encapsulation since 2020, especially precision engineering on microbial surfaces and microbial-mediated role. Currently, the encapsulation materials include polysaccharides and proteins, followed by lipids, which is a traditional mainstream trend, while novel plant extracts and polyphenols are on the rise. Other natural materials and processing by-products are also involved. The encapsulation types are divided into rough multicellular encapsulation, precise single-cell encapsulation, and microbial-mediated encapsulation. Recent emerging techniques include cryomilling, 3D printing, spray-drying with a three-fluid coaxial nozzle, and microfluidic. Encapsulated probiotics applied in food is an upward trend in which "classic probiotic foods" (yogurt, cheese, butter, chocolate, etc.) are dominated, supplemented by "novel probiotic foods" (tea, peanut butter, and various dry-based foods). Future efforts mainly include the effect of novel encapsulation materials on probiotics in the gut, encapsulation strategy oriented by microbial enthusiasm and precise encapsulation, development of novel techniques that consider both cost and efficiency, and co-encapsulation of multiple strains. In conclusion, encapsulation provides a strong impetus for the food application of probiotics.

Hydrogels as promising carriers for the delivery of food bioactive ingredients

The burden of public health challenges associated with the western dietary and living style is growing. Nutraceuticals have been paid increasing attentions due to their effects in promotion of health. However, in the gastrointestinal (GI) tract, the nutraceuticals suffer from not only the harsh acidic environment of the stomach and a variety of digestive enzymes, but also the antibacterial activity of intestinal bile salts and the action of protease from the gut microbiota. The amount of the nutraceuticals arriving at the sites in GI tract for absorption or exerting the bioactivities is always unfortunately limited, which puts forward high requirements for protection of nutraceuticals in a certain high contents during oral consumption. Hydrogels are three-dimensional polymeric porous networks formed by the cross-linking of polymer chains, which can hold huge amounts of water. Compared with other carries with the size in microscopic scale such as nanoparticle and microcapsules, hydrogels could be considered to be more suitable delivery systems in food due to their macroscopic bulk properties, adjustable viscoelasticity and large spatial structure for embedding nutraceuticals. Regarding to the applications in food, natural polymer-based hydrogels are commonly safe and popular due to their source with the appealing characteristics of affordability, biodegradability and biocompatibility. Although chemical crosslinking has been widely utilized in preparation of hydrogels, it prefers the physical crosslinking in the researches in food. The reasonable design for the structure of natural polymeric hydrogels is essential for seeking the favorable functionalities to apply in the delivery system, and it could be possible to obtain the enhanced adhesive property, acid stability, resistant to bile salt, and the controlled release behavior. The hydrogels prepared with proteins, polysaccharides or the mix of them to deliver the functional ingredients, mainly the phenolic components, vitamins, probiotics are discussed to obtain inspiration for the wide applications in delivery systems. Further efforts might be made in the in situ formation of hydrogels in GI tract through the interaction among food polymers and small-molecular ingredients, elevation of the loading contents of nutraceuticals in hydrogels, development of stomach adhesive hydrogels as well as targeting modification of gut microbiota by the hydrogels.

Novel Developments on Stimuli-Responsive Probiotic Encapsulates: From Smart Hydrogels to Nanostructured Platforms

Biomaterials engineering and biotechnology have advanced significantly towards probiotic encapsulation with encouraging results in assuring sufficient bioactivity. However, some major challenges remain to be addressed, and these include maintaining stability in different compartments of the gastrointestinal tract (GIT), favoring adhesion only at the site of action, and increasing residence times. An alternative to addressing such challenges is to manufacture encapsulates with stimuli-responsive polymers, such that controlled release is achievable by incorporating moieties that respond to chemical and physical stimuli present along the GIT. This review highlights, therefore, such emerging delivery matrices going from a comprehensive description of addressable stimuli in each GIT compartment to novel synthesis and functionalization techniques to currently employed materials used for probiotic’s encapsulation and achieving multi-modal delivery and multi-stimuli responses. Next, we explored the routes for encapsulates design to enhance their performance in terms of degradation kinetics, adsorption, and mucus and gut microbiome interactions. Finally, we present the clinical perspectives of implementing novel probiotics and the challenges to assure scalability and cost-effectiveness, prerequisites for an eventual niche market penetration.