Discovery of a bacterial peptide as a modulator of GLP-1 and metabolic disease.

Early work in rodents highlighted the gut microbiota's importance in metabolic disease, including Type II Diabetes Mellitus (T2DM) and obesity. Glucagon-like peptide-1 (GLP-1), an incretin secreted by L-cells lining the gastrointestinal epithelium, has important functions: promoting insulin secretion, insulin sensitivity, and ß-cell mass, while inhibiting gastric emptying and appetite. We set out to identify microbial strains with GLP-1 stimulatory activity as potential metabolic disease therapeutics. Over 1500 human-derived strains were isolated from healthy individuals and screened for GLP-1 modulation by incubating bacterial cell-free supernatants with NCI H716 L-cells. Approximately 45 strains capable of increasing GLP-1 were discovered. All GLP-1 positive strains were identified as Staphylococcus epidermidis by 16S rRNA sequencing. Mass spectrometry analysis identified a 3 kDa peptide, Hld (delta-toxin), present in GLP-1 positive supernatants but absent in GLP-1 neutral supernatants. Studies in NCI-H716 cells and human jejunal enteroids engineered to make more enteroendocrine cells demonstrated that Hld alone is sufficient to enhance GLP-1 secretion. When administered in high-fat-fed mice, Hld-producing S. epidermidis significantly reduced markers associated with obesity and T2DM. Further characterization of Hld suggests GLP-1 stimulatory action of Hld occurs via calcium signaling. The presented results identify a novel host-microbe interaction which may ultimately lead to the development of a microbial peptide-based therapeutic for metabolic disease.

Degradation of the Incretin Hormone Glucagon-Like Peptide-1 (GLP-1) by Enterococcus faecalis Metalloprotease GelE.

Metabolic diseases, including type 2 diabetes and obesity, have become increasingly prevalent global health concerns. Studies over the past decade have established connections between the gastrointestinal microbiota and host metabolism, but the mechanisms behind these connections are only beginning to be understood. We were interested in identifying microbes that have the ability to modulate the levels of the incretin hormone glucagon-like peptide-1 (GLP-1). Using a human-derived cell line that is capable of secreting GLP-1 in response to stimulatory ligands (NCI-H716), we identified supernatants from several bacterial isolates that were capable of decreasing GLP-1 levels, including several strains of Enterococcus faecalis We further identified the secreted protease GelE, an established virulence factor from E. faecalis, as being responsible for GLP-1 inhibition via direct cleavage of GLP-1 by GelE. Finally, we demonstrated that E. faecalis supernatants can disrupt a colonic epithelial monolayer and cleave GLP-1 in a gelE-dependent manner. This work suggests that a secreted factor from an intestinal microbe can traverse the epithelial barrier and impact levels of an important intestinal hormone.IMPORTANCE Humans have a complex and interconnected relationship with their gastrointestinal microbiomes, yet our interest in the microbiome tends to focus on overt pathogenic or probiotic activities, leaving the roles that commensal species may have on host physiology and metabolic processes largely unexplored. Commensal organisms in the microbiome produce and secrete many factors that have an opportunity to interact with the gastrointestinal tract and host biology. Here, we show that a secreted protease from E. faecalis, GelE, is able to degrade the gastrointestinal hormone GLP-1, which is responsible for regulating glucose homeostasis and appetite in the body. The disruption of natural GLP-1 signaling by GelE may have significant consequences for maintaining healthy blood glucose levels and in the development of metabolic disease. Furthermore, this work deepens our understanding of specific host-microbiome interactions.

Human Intestinal Enteroids With Inducible Neurogenin-3 Expression as a Novel Model of Gut Hormone Secretion.

BACKGROUND & AIMS: Enteroendocrine cells (EECs) are specialized epithelial cells that produce molecules vital for intestinal homeostasis, but because of their limited numbers, in-depth functional studies have remained challenging. Human intestinal enteroids (HIEs) that are derived from intestinal crypt stem cells are biologically relevant in an in vitro model of the intestinal epithelium. HIEs contain all intestinal epithelial cell types; however, similar to the intestine, HIEs spontaneously produce few EECs, which limits their study. METHODS: To increase the number of EECs in HIEs, we used lentivirus transduction to stably engineer jejunal HIEs with doxycycline-inducible expression of neurogenin-3 (NGN3), a transcription factor that drives EEC differentiation (tetNGN3-HIEs). We examined the impact of NGN3 induction on EECs by quantifying the increase in the enterochromaffin cells and other EEC subtypes. We functionally assessed secretion of serotonin and EEC hormones in response to norepinephrine and rotavirus infection. RESULTS: Treating tetNGN3-HIEs with doxycycline induced a dose-dependent increase of chromogranin A (ChgA)-positive and serotonin-positive cells, showing increased enterochromaffin cell differentiation. Despite increased ChgA-positive cells, other differentiated cell types of the epithelium remained largely unchanged by gene expression and immunostaining. RNA sequencing of doxycycline-induced tetNGN3-HIEs identified increased expression of key hormones and enzymes associated with several other EEC subtypes. Doxycycline-induced tetNGN3-HIEs secreted serotonin, monocyte chemoattractant protein-1, glucose-dependent insulinotropic peptide, peptide YY, and ghrelin in response to norepinephrine and rotavirus infection, further supporting the presence of multiple EEC types. CONCLUSIONS: We have combined HIEs and inducible-NGN3 expression to establish a flexible in vitro model system for functional studies of EECs in enteroids and advance the molecular and physiological investigation of EECs.

Cholesterol assimilation by Lactobacillus probiotic bacteria: an in vitro investigation.

Excess cholesterol is associated with cardiovascular diseases (CVD), an important cause of mortality worldwide. Current CVD therapeutic measures, lifestyle and dietary interventions, and pharmaceutical agents for regulating cholesterol levels are inadequate. Probiotic bacteria have demonstrated potential to lower cholesterol levels by different mechanisms, including bile salt hydrolase activity, production of compounds that inhibit enzymes such as 3-hydroxy-3-methylglutaryl coenzyme A, and cholesterol assimilation. This work investigates 11 Lactobacillus strains for cholesterol assimilation. Probiotic strains for investigation were selected from the literature: Lactobacillus reuteri NCIMB 11951, L. reuteri NCIMB 701359, L. reuteri NCIMB 702655, L. reuteri NCIMB 701089, L. reuteri NCIMB 702656, Lactobacillus fermentum NCIMB 5221, L. fermentum NCIMB 8829, L. fermentum NCIMB 2797, Lactobacillus rhamnosus ATCC 53103 GG, Lactobacillus acidophilus ATCC 314, and Lactobacillus plantarum ATCC 14917. Cholesterol assimilation was investigated in culture media and under simulated intestinal conditions. The best cholesterol assimilator was L. plantarum ATCC 14917 (15.18±0.55 mg/10(10) cfu) in MRS broth. L. reuteri NCIMB 701089 assimilated over 67% (2254.70±63.33 mg/10(10) cfu) of cholesterol, the most of all the strains, under intestinal conditions. This work demonstrates that probiotic bacteria can assimilate cholesterol under intestinal conditions, with L. reuteri NCIMB 701089 showing great potential as a CVD therapeutic.

Microencapsulated Bifidobacterium longum subsp. infantis ATCC 15697 favorably modulates gut microbiota and reduces circulating endotoxins in F344 rats.

The gut microbiota is a bacterial bioreactor whose composition is an asset for human health. However, circulating gut microbiota derived endotoxins cause metabolic endotoxemia, promoting metabolic and liver diseases. This study investigates the potential of orally delivered microencapsulated Bifidobacterium infantis ATCC 15697 to modulate the gut microbiota and reduce endotoxemia in F344 rats. The rats were gavaged daily with saline or microencapsulated B. infantis ATCC 15697. Following 38 days of supplementation, the treated rats showed a significant (P < 0.05) increase in fecal Bifidobacteria (4.34 ± 0.46 versus 2.45 ± 0.25% of total) and B. infantis (0.28 ± 0.21 versus 0.52 ± 0.12 % of total) and a significant (P < 0.05) decrease in fecal Enterobacteriaceae (0.80 ± 0.45 versus 2.83 ± 0.63% of total) compared to the saline control. In addition, supplementation with the probiotic formulation reduced fecal (10.52 ± 0.18 versus 11.29 ± 0.16 EU/mg; P = 0.01) and serum (0.33 ± 0.015 versus 0.30 ± 0.015 EU/mL; P = 0.25) endotoxins. Thus, microencapsulated B. infantis ATCC 15697 modulates the gut microbiota and reduces colonic and serum endotoxins. Future preclinical studies should investigate the potential of the novel probiotic formulation in metabolic and liver diseases.

The gut microbiome, probiotics, bile acids axis, and human health.

The human gut microbiome produces potent ligands to bile acid receptors, and probiotics could act as therapeutics of bile acid dysmetabolism. A recent study in Cell Reports demonstrates that probiotic VSL#3 affects bile acid deconjugation and excretion, as well as the gut-liver FXR-FGF15 axis.

Intranasal delivery of chitosan-siRNA nanoparticle formulation to the brain.

Neurodegeneration is characterized by a progressive loss of neuron structure and function. Most neurodegenerative diseases progress slowly over the time. There is currently no cure available for any neurodegenerative disease, and the existing therapeutic interventions only alleviate the symptoms of the disease. The advances in the drug discovery research have come to a halt with a lack of effective means to deliver drugs at the targeted site. In addition, the route of delivering the drugs is equally important as most invasive techniques lead to postoperative complications. This chapter focuses on a non-invasive, intranasal mode of therapeutic delivery using nanoparticles, which is currently being explored. The intranasal route of delivery is a well-established route to deliver drugs via the olfactory and trigeminal neuronal pathways. It is known to be the fastest and most effective way to bypass the blood-brain barrier to reach the central nervous system. The presented chapter highlights the method of intranasal delivery in mice using chitosan-siRNA nanoparticle formulation, under mild anesthesia and the identification of successful siRNA delivery in the brain tissues, through histology and other well-established laboratory protocols.

Probiotics for the prevention and treatment of allergies, with an emphasis on mode of delivery and mechanism of action.

Allergy, also termed type I hypersensitivity, is defined as a "disease following a response by the immune system to an otherwise innocuous antigen". The prevalence of allergies is high and escalating, with almost half the populations of North America and Europe having allergies to one or more common environmental antigens. Although rarely life-threatening allergies cause much distress and pose an important economic burden. Recent studies demonstrate the importance of the commensal bacteria of the gastrointestinal tract, termed the microbiota, in stimulating and modulating the immune system. This goes hand-in-hand with the hygiene hypothesis, proposed by Strachan in 1989. With this in mind, the use of pre- and probiotics has gained interest to prevent and treat allergies through modulation of the gut microbiota and the immune system. Probiotics, namely Lactobacilli and Bifidobacteria, are live microorganisms that can be incorporated in the diet in the form of functional foods or dietary supplements to beneficially influence the host. In recent studies, probiotic formulations demonstrated the capability to successfully modulate allergic rhinitis, atopic disorders and food-related allergies. A number of probiotic mechanisms of action are involved in controlling hypersensitivity responses, many of which are still not yet understood. Microencapsulation has gained importance as a device for the oral delivery of probiotic cells and may play an important role in the development of a successful probiotic formulation to treat and prevent allergies. Despite the promising research on probiotic biotherapeutics, further investigations are required to develop a successful therapeutic to treat and prevent allergies.

Effect of orally administered L. fermentum NCIMB 5221 on markers of metabolic syndrome: an in vivo analysis using ZDF rats.

Metabolic syndrome, encompassing type 2 diabetes mellitus and cardiovascular disease, is a growing health concern of industrialized countries. Ferulic acid (FA) is a phenolic acid found in foods normally consumed by humans that has demonstrated antioxidant activity, cholesterol-lowering capabilities, and anti-tumorigenic properties. Select probiotic bacteria, including Lactobacillus fermentum NCIMB 5221, produce FA due to intrinsic ferulic acid esterase activity. The aim of the present research was to investigate a FA-producing probiotic, L. fermentum NCIMB 5221, as a biotherapeutic for metabolic syndrome. The probiotic formulation was administered daily for 8 weeks to Zucker diabetic fatty (ZDF) rats, a model of hyperlipidemia and hyperglycemia. Results show that the probiotic formulation reduced fasting insulin levels and insulin resistance, significantly reduced serum triglycerides (p = 0.016), lowered serum low-density lipoprotein cholesterol levels (p = 0.008), and significantly reduced the atherogenic (p = 0.016) and atherosclerosis (p = 0.012) index as compared to the control animals. In addition, the probiotic formulation significantly increased high-density lipoprotein cholesterol levels (p = 0.041) as compared to the control animals. This research indicates that administration of the FA-producing L. fermentum NCIMB 5221 has the potential to reduce insulin resistance, hyperinsulinemia, hypercholesterolemia, and other markers involved in the pathogenesis of metabolic syndrome. Further studies are required to investigate the human clinical potential of the probiotic formulation in affecting the markers and pathogenesis of metabolic syndrome.

Enrichment of Bifidobacterium longum subsp. infantis ATCC 15697 within the human gut microbiota using alginate-poly-L-lysine-alginate microencapsulation oral delivery system: an in vitro analysis using a computer-controlled dynamic human gastrointestinal model.

This study evaluates alginate-poly-L-lysine-alginate Bifidobacterium longum subsp. infantis ATCC 15697-loaded microcapsules to enrich the human gut microbiota. The cell survival of alginate-poly-L-lysine-alginate microencapsulated B. infantis ATCC 15697 in gastric acid, bile, and through human gastrointestinal transit was investigated, as well as the formulation's effect on the gut microbiota. Results show that microencapsulation increases B. infantis ATCC 15697 cell survival at pH1.0 (33.54 ± 2.80% versus <1.00 ± 0.00%), pH1.5 (41.15 ± 2.06% versus <1.00 ± 0.00%), pH2.0 (60.88 ± 1.73% versus 36.01 ± 2.63%), pH3.0 (75.43 ± 1.23% versus 46.30 ± 1.43%), pH4.0 (71.40 ± 2.02% versus 47.75 ± 3.12%) and pH5.0 (73.88 ± 3.79% versus 58.93 ± 2.26%) (p < 0.05). In addition, microencapsulation increases cell survival at 0.5% (76.85 ± 0.80% versus 70.77 ± 0.64%), 1.0% (59.99 ± 0.97% versus 53.47 ± 0.58%) and 2.0% (53.10 ± 1.87% versus 44.59 ± 1.52%) (p < 0.05) (w/v) bile. Finally, daily administration of alginate-poly-L-lysine-alginate microencapsulated B. infantis ATCC 15697 in a human gastrointestinal model induces a significant enrichment of B. infantis within the ascending (184.51 ± 17.30% versus 53.83 ± 17.82%; p < 0.05), transverse (174.79 ± 25.32% versus 73.17 ± 15.30%; p < 0.05) and descending (94.90 ± 25.22% versus 46.37 ± 18.93%; p > 0.05) colonic microbiota.

Systemic siRNA Delivery via Peptide-Tagged Polymeric Nanoparticles, Targeting PLK1 Gene in a Mouse Xenograft Model of Colorectal Cancer.

Polymeric nanoparticles were developed from a series of chemical reactions using chitosan, polyethylene glycol, and a cell-targeting peptide (CP15). The nanoparticles were complexed with PLK1-siRNA. The optimal siRNA loading was achieved at an N : P ratio of 129.2 yielding a nanoparticle size of >200 nm. These nanoparticles were delivered intraperitoneally and tested for efficient delivery, cytotoxicity, and biodistribution in a mouse xenograft model of colorectal cancer. Both unmodified and modified chitosan nanoparticles showed enhanced accumulation at the tumor site. However, the modified chitosan nanoparticles showed considerably, less distribution in other organs. The relative gene expression as evaluated showed efficient delivery of PLK1-siRNA (0.5 mg/kg) with 50.7 ± 19.5% knockdown (P = 0.031) of PLK1 gene. The in vivo data reveals no systemic toxicity in the animals, when tested for systemic inflammation and liver toxicity. These results indicate a potential of using peptide-tagged nanoparticles for systemic delivery of siRNA at the targeted tumor site.

Development and characterization of chitosan-PEG-TAT nanoparticles for the intracellular delivery of siRNA.

Recently, cell-penetrating peptides have been proposed to translocate antibodies, proteins, and other molecules in targeted drug delivery. The proposed study presents the synthesis and characterization of a peptide-based chitosan nanoparticle for small interfering RNA (siRNA) delivery, in-vitro. Specifically, the synthesis included polyethylene glycol (PEG), a hydrophilic polymer, and trans-activated transcription (TAT) peptide, which were chemically conjugated on the chitosan polymer. The conjugation was achieved using N-Hydroxysuccinimide-PEG-maleimide (heterobifunctional PEG) as a cross-linker, with the bifunctional PEG facilitating the amidation reaction through its N-Hydroxysuccinimide group and reacting with the amines on chitosan. At the other end of PEG, the maleimide group was chemically conjugated with the cysteine-modified TAT peptide. The degree of substitution on chitosan with PEG and on PEG with TAT was confirmed using colorimetric assays. The resultant polymer was used to form nanoparticles complexing siRNA, which were then characterized for particle size, morphology, cellular uptake, and cytotoxicity. The nanoparticles were tested in-vitro on mouse neuroblastoma cells (Neuro2a). Particle size and surface charge were characterized and an optimal pH condition and PEG molecular weight were determined to form sterically stable nanoparticles. Results indicate 7.5% of the amines in chitosan polymer were conjugated to the PEG and complete conjugation of TAT peptide was observed on the synthesized PEGylated chitosan polymer. Compared with unmodified chitosan nanoparticles, the nanoparticles formed at pH 6 were monodispersed and of <100 nm in size, exhibiting maximum cell transfection ability and very low cytotoxicity. Thus, this research may be of significance in translocating biotherapeutic molecules for intracellular delivery applications.

Novel probiotic dissolvable carboxymethyl cellulose films as oral health biotherapeutics: in vitro preparation and characterization.

OBJECTIVES: Oral health is influenced by the mouth's resident microorganisms. Dental caries and periodontitis are oral disorders caused by imbalances in the oral microbiota. Probiotics have potential for the prevention and treatment of oral disorders. Current formulations, including supplements and foods, have limitations for oral delivery including short storage time, low residence time in the mouth, effects on food consistency, and low patient compliance. Oral thin films (OTFs) may be efficient in delivering probiotics to the mouth. This research aims to develop a novel carboxymethyl cellulose (CMC)-probiotic-OTF to deliver probiotics for the treatment/prevention of oral disorders. METHODS: CMC-OTFs were developed with varying CMC concentration (1.25 - 10 mg/mL), weight (5 - 40 g), thickness (16 - 262 µm), hygroscopicity (30.8 - 78.9 mg/cm(2) film), and dissolving time (135 - 600 s). The 10 g 5 mg/mL CMC-OTF was selected and used to incorporate Lactobacillus fermentum NCIMB 5221 (6.75 × 10(8) cells/film), a probiotic with anti-inflammatory potential for periodontitis treatment and capable of inhibiting microorganisms responsible for dental caries and oral candidiasis. RESULTS: The CMC-OTF maintained probiotic viability and antioxidant activity following 150 days of storage with a production of 549.52 ± 26.08 µM Trolox equivalents. CONCLUSION: This research shows the successful development and characterization of a novel probiotic-CMC-OTF with potential as an oral health biotherapeutic.

Probiotics in colorectal cancer (CRC) with emphasis on mechanisms of action and current perspectives.

Colorectal cancer (CRC) is the third most common form of cancer. Diverse therapies such as chemotherapy, immunotherapy and radiation have shown beneficial effects, but are limited because of their safety and toxicity. Probiotic formulations have shown great promise in CRC as preventive and early stage therapeutics. This review highlights the importance of a balanced intestinal microbiota and summarizes the recent developments in probiotics for treating CRC. Specifically, this report describes evidence of the role of probiotics in modulating the microbiota, in improving the physico-chemical conditions of the gut and in reducing oxidative stress. It also discusses the mechanisms of probiotics in inhibiting tumour progression, in producing anticancer compounds and in modulating the host immune response. Even though some of these effects were observed in several clinical trials, when probiotic formulations were used as a supplement to CRC therapies, the application of probiotics as biotherapeutics against CRC still needs further investigation.

Oral probiotic microcapsule formulation ameliorates non-alcoholic fatty liver disease in Bio F1B Golden Syrian hamsters.

The beneficial effect of a microencapsulated feruloyl esterase producing Lactobacillus fermentum ATCC 11976 formulation for use in non-alcoholic fatty liver disease (NAFLD) was investigated. For which Bio F1B Golden Syrian hamsters were fed a methionine deficient/choline devoid diet to induce non-alcoholic fatty liver disease. Results, for the first time, show significant clinical benefits in experimental animals. Examination of lipids show that concentrations of hepatic free cholesterol, esterified cholesterol, triglycerides and phospholipids were significantly lowered in treated animals. In addition, serum total cholesterol, triglycerides, uric acid and insulin resistance were found to decrease in treated animals. Liver histology evaluations showed reduced fat deposits. Western blot analysis shows significant differences in expression levels of key liver enzymes in treated animals. In conclusion, these findings suggest the excellent potential of using an oral probiotic formulation to ameliorate NAFLD.

Effect of probiotics Lactobacillus and Bifidobacterium on gut-derived lipopolysaccharides and inflammatory cytokines: an in vitro study using a human colonic microbiota model.

Gut-derived lipopolysaccharides (LPS) are critical to the development and progression of chronic low-grade inflammation and metabolic diseases. In this study, the effects of probiotics Lactobacillus and Bifidobacterium on gut-derived lipopolysaccharide and inflammatory cytokine concentrations were evaluated using a human colonic microbiota model. Lactobacillus reuteri, L. rhamnosus, L. plantarum, Bifidobacterium animalis, B. bifidum, B. longum, and B. longum subsp. infantis were identified from the literature for their anti-inflammatory potential. Each bacterial culture was administered daily to a human colonic microbiota model during 14 days. Colonic lipopolysaccharides, and Gram-positive and negative bacteria were quantified. RAW 264.7 macrophage cells were stimulated with supernatant from the human colonic microbiota model. Concentrations of TNF-alpha, IL-1beta, and IL-4 cytokines were measured. Lipopolysaccharide concentrations were significantly reduced with the administration of B. bifidum (-46.45 +/- 5.65%), L. rhamnosus (-30.40 +/- 5.08%), B. longum (-42.50 +/- 1.28%), and B. longum subsp. infantis (-68.85 +/- 5.32%) (p < 0.05). Cell counts of Gram-negative and positive bacteria were distinctly affected by the probiotic administered. There was a probiotic strain-specific effect on immunomodulatory responses of RAW 264.7 macrophage cells. B. longum subsp. infantis demonstrated higher capacities to reduce TNF-alpha concentrations (-69.41 +/- 2.78%; p < 0.05) and to increase IL-4 concentrations (+16.50 +/- 0.59%; p < 0.05). Colonic lipopolysaccharides were significantly correlated with TNF-alpha and IL-1beta concentrations (p < 0.05). These findings suggest that specific probiotic bacteria, such as B. longum subsp. infantis, might decrease colonic lipopolysaccharide concentrations, which might reduce the proinflammatory tone. This study has noteworthy applications in the field of biotherapeutics for the prevention and/or treatment of inflammatory and metabolic diseases.

Cholesterol lowering with bile salt hydrolase-active probiotic bacteria, mechanism of action, clinical evidence, and future direction for heart health applications.

INTRODUCTION: Cardiovascular diseases (CVD) are the leading cause of global mortality and morbidity. Current CVD treatment methods include dietary intervention, statins, fibrates, niacin, cholesterol absorption inhibitors, and bile acid sequestrants. These formulations have limitations and, thus, additional treatment modalities are needed. Probiotic bacteria, especially bile salt hydrolase (BSH)-active probiotic bacteria, have demonstrated cholesterol-lowering efficacy in randomized controlled trials. AREAS COVERED: This review describes the current treatments for CVD and the need for additional therapeutics. Gut microbiota etiology of CVD, cholesterol metabolism, and the role of probiotic formulations as therapeutics for the treatment and prevention of CVD are described. Specifically, we review studies using BSH-active bacteria as cholesterol-lowering agents with emphasis on their cholesterol-lowering mechanisms of action. Potential limitations and future directions are also highlighted. EXPERT OPINION: Numerous clinical studies have concluded that BSH-active probiotic bacteria, or products containing them, are efficient in lowering total and low-density lipoprotein cholesterol. However, the mechanisms of action of BSH-active probiotic bacteria need to be further supported. There is also the need for a meta-analysis to provide better information regarding the therapeutic use of BSH-active probiotic bacteria. The future of BSH-active probiotic bacteria most likely lies as a combination therapy with already existing treatment options.

Design of a novel gut bacterial adhesion model for probiotic applications.

A new gut bacterial adhesion model has been developed. For this, a continuous-flow bioreactor packed with bacteria-coated beads was designed to simulate the gut lining and other features. In vitro model efficacy shows successful bacterial cell gut adhesions: bacterial adhesion was higher with mucin-alginate compared to controls. In feasibility study, adhesion of Lactobacillus fermentum NCIMB 5221 and Lactobacillus reuteri NCIMB 701359 was investigated for their metabolic activities for bile salt. Bile salt hydrolase (BSH)-active Lactobacillus reuteri exerted higher activity than non-BSH-active L. fermentum. This model has potential use in gut health, probiotic, bacterial cell gut adhesion and other delivery applications.

Synthesis of TAT peptide-tagged PEGylated chitosan nanoparticles for siRNA delivery targeting neurodegenerative diseases.

Delivery of therapeutic molecules to the brain for the treatment of Neurodegenerative diseases (ND) is a challenging task. This manuscript introduces a novel scheme of synthesizing peptide-tagged polyethylene glycol (PEG)ylated chitosan polymer to develop nanoparticles for siRNA delivery for use in ND. Specifically, this manuscript proposes a facile chemoselective conjugation of monomethoxy PEG, at the C2 hydroxyl group of chitosan polymer, with conjugation of PEG to a cell-penetrating peptide, Trans-Activator of Transcription. The synthesized Chitosan-PEG-TAT polymer was used to form the nanoparticles of approximately 5 nm, complexing siRNA to be delivered in neuronal cells (Neuro 2a), with no/minimal toxicity. The various intermediates and the final product formed during the synthesis were characterized using (1)H Nuclear Magnetic Resonance and Fourier Transform Infrared Spectroscopy spectra. The morphological details of the nanoparticles were studied using Transmission Electron Microscopy. The nanoparticles were tested to deliver a functional siRNA against the Ataxin-1 gene in an in-vitro established model of a ND Spinocerebellar ataxia (SCA1) over-expressing ataxin protein. The results indicate successful suppression of the SCA1 protein following 48 h of transfection. Result of this study has potential in ND like SCA, Parkinson's, Alzheimer's and others.

Microencapsulation for the Therapeutic Delivery of Drugs, Live Mammalian and Bacterial Cells, and Other Biopharmaceutics: Current Status and Future Directions.

Microencapsulation is a technology that has shown significant promise in biotherapeutics, and other applications. It has been proven useful in the immobilization of drugs, live mammalian and bacterial cells and other cells, and other biopharmaceutics molecules, as it can provide material structuration, protection of the enclosed product, and controlled release of the encapsulated contents, all of which can ensure efficient and safe therapeutic effects. This paper is a comprehensive review of microencapsulation and its latest developments in the field. It provides a comprehensive overview of the technology and primary goals of microencapsulation and discusses various processes and techniques involved in microencapsulation including physical, chemical, physicochemical, and other methods involved. It also summarizes the state-of-the-art successes of microencapsulation, specifically with regard to the encapsulation of microorganisms, mammalian cells, drugs, and other biopharmaceutics in various diseases. The limitations and future directions of microencapsulation technologies are also discussed.