The study of the potential application of nanofiber microcapsules loading lactobacillus in targeted delivery of digestive tract in vitro

Can polymeric nanofibers effectively preserve and deliver live therapeutic bacteria?

Probiotics and live therapeutic bacteria (LTB), their strictly regulated therapeutic counterpart, are increasingly important in treating and preventing biofilm-related diseases. This necessitates new approaches to (i) preserve bacterial viability during manufacturing and storage and (ii) incorporate LTB into delivery systems for enhanced therapeutic efficacy. This review explores advances in probiotic and LTB product development, focusing on preservation, protection, and improved delivery. Preservation of bacteria can be achieved by drying methods that decelerate metabolism. These methods introduce stresses affecting viability which can be mitigated with suitable excipients like polymeric or low molecular weight stabilizers. The review emphasizes the incorporation of LTB into polymer-based nanofibers via electrospinning, enabling simultaneous drying, encapsulation, and delivery system production. Optimization of bacterial survival during electrospinning and storage is discussed, as well as controlled LTB release achievable through formulation design using gel-forming, gastroprotective, mucoadhesive, and pH-responsive polymers. Evaluation of the presence of the actual therapeutic strains, bacterial viability and activity by CFU enumeration or alternative analytical techniques is presented as a key aspect of developing effective and safe formulations with LTB. This review offers insights into designing delivery systems, especially polymeric nanofibers, for preservation and delivery of LTB, guiding readers in developing innovative biotherapeutic delivery systems.

A review on polysaccharide-based delivery systems for edible bioactives: pH responsive, controlled release, and emerging applications

pH changes occur during bodily lesions, presenting an opportunity for leveraging pH-responsive delivery systems as signals for a targeted response. This review explores the design and application of pH-responsive delivery systems based on natural polysaccharides for the controlled release of bioactives. The article examines the development of diverse delivery carriers, including nanoparticles, nanofibers, nanogels, core-shell carriers, hydrogels, emulsions as well as liposomes and their capacity to respond to pH variations, enabling the precise and targeted delivery of bioactives within the human body. These polysaccharide-based delivery systems can be made pH-responsive by modulating the charge of polybasic or polyacidic polysaccharides, inducing swelling of the carrier and subsequent release of the encapsulated bioactives. These pH-responsive systems show promise in stabilizing under acidic conditions for enhanced retention in the stomach during oral delivery while also enabling targeted release at low pH sites such as tumors and wounds, thereby accelerating wound healing and aiding in cancer therapy and inflammation treatment. pH can co-respond with a variety of stimuli, including temperature, enzymes and reactive oxygen species, enabling more precise responses to the microenvironment for targeted delivery. It provides solid theoretical foundations for the advancement of personalized nutrition and therapeutics through controlled and responsive release technologies.

Improvement in probiotic intestinal survival by electrospun milk fat globule membrane-pullulan nanofibers: Fabrication and structural characterization

Studies have demonstrated the protective effect of milk fat globule membrane (MFGM) on probiotics in harsh environments. However, currently, there are no reports on the encapsulation of probiotics using MFGM. In this study, MFGM and pullulan (PUL) polysaccharide fibers were prepared by electrostatic spinning and used to encapsulate probiotics, with whey protein isolates (WPI)/PUL as the control. The morphology, physical properties, mechanical properties, survival, and stability of the encapsulated Lacticaseibacillus rhamnosus GG (LGG) were studied. The results showed that the MFGM/PUL solution had significant effects on pH, viscosity, conductivity, and stability. Electrostatic spinning improved the mechanical properties and encapsulation ability of the polymer formed by MFGM/PUL. LGG encapsulated in MFGM/PUL nanofibers survived rate was higher than WPI/PUL nanofibers in mimic intestinal juice, which could be attributed to the phospholipid content contained in MFGM. These results demonstrate that MFGM is a promising material for probiotic encapsulation, providing an important basis for the potential use of MFGM/PUL nanofibers as a robust encapsulation matrix.

Microencapsule delivery systems of functional substances for precision nutrition

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

Targeted delivery of food functional ingredients in precise nutrition: design strategy and application of nutritional intervention

With the high incidence of chronic diseases, precise nutrition is a safe and efficient nutritional intervention method to improve human health. Food functional ingredients are an important material base for precision nutrition, which have been researched for their application in preventing diseases and improving health. However, their poor solubility, stability, and bad absorption largely limit their effect on nutritional intervention. The establishment of a stable targeted delivery system is helpful to enhance their bioavailability, realize the controlled release of functional ingredients at the targeted action sites in vivo, and provide nutritional intervention approaches and methods for precise nutrition. In this review, we summarized recent studies about the types of targeted delivery systems for the delivery of functional ingredients and their digestion fate in the gastrointestinal tract, including emulsion-based delivery systems and polymer-based delivery systems. The building materials, structure, size and charge of the particles in these delivery systems were manipulated to fabricate targeted carriers. Finally, the targeted delivery systems for food functional ingredients have gained some achievements in nutritional intervention for inflammatory bowel disease (IBD), liver disease, obesity, and cancer. These findings will help in designing fine targeted delivery systems, and achieving precise nutritional intervention for food functional ingredients on human health.

Nanofiber could deliver lactic acid bacteria to the intestine of ruminant in vitro experiment

This study investigates the use of nanofiber microcapsules produced by electrostatic spinning as a carrier for the delivery of lactic acid bacteria (LAB) to the intestine of ruminants. We hypothesized that the LAB encapsulated into nanofiber microcapsules can be delivered to a ruminant's intestinal tract with little effect on the rumen fermentation and related bacteria. The in vitro experiment included three treatments: control group; 0.01g Lactobacillus acidophilus NCFM (L. acidophilus NCFM) encapsulated in nanofiber microcapsules by electrostatic spinning group (ELAN, 2.0 × 10¹¹  CFU/g); and 0.01g L. acidophilus NCFM powder group (LANP, 2.0 × 10¹¹  CFU/g), each incubated with 30 ml of buffer rumen fluid for 48h to determine the effect on rumen fermentation, then the abundance of L. acidophilus NCFM in the intestine was estimated using the modified in vitro three-step procedure. Treatment responses were statistically analysed using one-way ANOVA. The results showed that compared to the control, the ELAN group had a significant increase in pH (p < 0.05), while the LANP group had a non-significant decrease in pH (p > 0.05). LANP and ELAN groups had no significant influence on total volatile fatty acid and individual volatile fatty acids (p > 0.05), apart from isobutyric acid of both groups, which reduced (p < 0.05). ELAN group had a decreasing trend of gas production and dry matter digestion, while the LANP group increased them significantly (p < 0.05). During the 16h and 48h rumen incubation, compared with control, there was no significant change in all bacteria in the ELAN group (p > 0.05), while the LANP group increased the relative abundance levels of S. bovis, S. ruminantium, M. elsdenii, F. succinogenes, B. fibrisolvens, Lactobacillus, L. acidophilus NCFM (p < 0.05). In the intestinal part, compared with control, the relative abundance of L. acidophilus NCFM in the ELAN group increased significantly (p < 0.05), while the result was not observed in the LANP group. We concluded based on our findings that L. acidophilus NCFM could be protected by nanofiber microcapsules and delivered to the intestinal site with little influence on the rumen fermentation and bacterial community, suggesting nanofiber microcapsules prepared by electrospinning technology could be used as a carrier for rumen-protected study.

Preparation and Properties of Electrospun PLLA/PTMC Scaffolds

Poly(L-lactide) (PLLA) and PLLA/poly(trimethylene carbonate) (PTMC) scaffolds characterised by different PLLA:PTMC mass ratios (10:0, 9:1, 8:2, 7:3, 6:4 and 5:5) were prepared via electrospinning. The results showed that increasing the PTMC content in the spinning solution caused the following effects: (1) the diameter of the prepared PLLA/PTMC electrospun fibres gradually increased from 188.12 ± 48.87 nm (10:0) to 584.01 ± 60.68 nm (5:5), (2) electrospun fibres with uniform diameters and no beads could be prepared at the PTMC contents of >30%, (3) the elastic modulus of the fibre initially increased and then decreased, reaching a maximum value of 74.49 ± 8.22 Mpa (5:5) and (4) the elongation at the breaking point of the fibres increased gradually from 24.71% to 344.85%. Compared with the PLLA electrospun fibrous membrane, the prepared PLLA/PTMC electrospun fibrous membrane exhibited considerably improved mechanical properties while maintaining good histocompatibility.

The Recent Trend in the Use of Multistrain Probiotics in Livestock Production: An Overview

It has been established that introducing feed additives to livestock, either nutritional or non-nutritional, is beneficial in manipulating the microbial ecosystem to maintain a balance in the gut microbes and thereby improving nutrient utilization, productivity, and health status of animals. Probiotic use has gained popularity in the livestock industry, especially since antimicrobial growth promoter's use has been restricted due to the challenge of antibiotic resistance in both animals and consumers of animal products. Their usage has been linked to intestinal microbial balance and improved performance in administered animals. Even though monostrain probiotics could be beneficial, multistrain probiotics containing two or more species or strains have gained considerable attention. Combining different strains has presumably achieved several health benefits over single strains due to individual isolates' addition and positive synergistic adhesion effects on animal health and performance. However, there has been inconsistency in the effects of the probiotic complexes in literature. This review discusses multistrain probiotics, summarizes selected literature on their effects on ruminants, poultry, and swine productivity and the various modes by which they function.