Journal of pharmacy & pharmaceutical sciences : a publication of the Canadian Society for Pharmaceutical Sciences, Société canadienne des sciences pharmaceutiques, Jan 24, 2004
Bacterial cells can be engineered to synthesize a wide array of disease modifying substrates such... more Bacterial cells can be engineered to synthesize a wide array of disease modifying substrates such as cytokines, vaccines and antibodies; however, their use as an orally delivered therapeutic is limited by poor gastrointestinal (GI) survival and instigation of immunogenic response. Artificial cell microcapsules have been well studied as a means to overcome such problems, however, presently obtainable microcapsules have limitations. This study summarizes a novel microcapsule design specifying its preparation and GI stability in-vitro. Multilayer APPPA microcapsules were designed, prepared and characterized in-vitro for bacterial cell oral delivery using Lactobacillus reuteri cells as a model. Microcapsule structural integrity, mechanical stability, and GI survival studies were performed in simulated gastric (SGF) and intestinal (SIF) fluids in various pH conditions at 37.2 degrees C and compared with presently available alginate/poly-l-lysine/alginate (APA) microcapsules. HPLC was use...
Several studies have reported limited or no reduction in serum cholesterol in response to probiot... more Several studies have reported limited or no reduction in serum cholesterol in response to probiotic formulations. Recently, probiotics have shown promise in treating metabolic disease due to improved strain selection and delivery technologies. The aim of the present study was to evaluate the cholesterol-lowering efficacy of a yoghurt formulation containing microencapsulated bile salt hydrolase (BSH)-active Lactobacillus reuteri NCIMB 30242, taken twice per d over 6 weeks, in hypercholesterolaemic adults. A total of 114 subjects completed this double-blind, placebo-controlled, randomised, parallel-arm, multi-centre study. This interventional study included a 2-week washout, 2-week run-in and 6-week treatment period. Subjects were randomised to consume either yoghurts containing microencapsulated L. reuteri NCIMB 30242 or placebo yoghurts. Over the intervention period, subjects consuming yoghurts containing microencapsulated L. reuteri NCIMB 30242 attained significant reductions in LD...
Regulatory toxicology and pharmacology : RTP, 2012
A significant number of human clinical trials have reported no adverse effects associated with co... more A significant number of human clinical trials have reported no adverse effects associated with consumption of Lactobacillus reuteri (L. reuteri). In the present study, the clinical safety and toxicology of oral ingestion of supplement capsules containing L. reuteri NCIMB 30242 was investigated. A randomized group of 131 subjects received a dose of 2.9×10⁹ CFU L. reuteri NCIMB 30242 capsules (n=67) or placebo capsules (n=64) twice daily for 9 weeks. Clinical chemistry and hematological parameters of safety were analyzed. The frequency, duration and intensity of adverse events (AE)s and clinical significance of safety parameters were recorded for both groups. No clinically significant differences between the probiotic capsule and placebo capsule treated groups were detected in either the blood clinical chemistry or hematology results. The frequency and intensity of AEs was similar in the two groups. These results demonstrate that administration of a twice daily dose of 2.9×10⁹ CFU was...
We performed an analysis to determine the importance of bile acid modification genes in the gut m... more We performed an analysis to determine the importance of bile acid modification genes in the gut microbiome of inflammatory bowel disease and type 2 diabetic patients. We used publicly available metagenomic datasets from the Human Microbiome Project and the MetaHIT consortium, and determined the abundance of bile salt hydrolase gene (bsh), 7 alpha-dehydroxylase gene (adh) and 7-alpha hydroxysteroid dehydrogenase gene (hsdh) in fecal bacteria in diseased populations of Crohn's disease (CD), Ulcerative Colitis (UC) and Type 2 diabetes mellitus (T2DM). Phylum level abundance analysis showed a significant reduction in Firmicute-derived bsh in UC and T2DM patients but not in CD patients, relative to healthy controls. Reduction of adh and hsdh genes was also seen in UC and T2DM patients, while an increase was observed in the CD population as compared to healthy controls. A further analysis of the bsh genes showed significant differences in the correlations of certain Firmicutes familie...
Cardiovascular diseases (CVD) are the leading cause of global mortality and morbidity. Current CV... more 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. 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. Numerous clinical stud...
This article describes the preparation and in vitro characterization of novel genipin cross-linke... more This article describes the preparation and in vitro characterization of novel genipin cross-linked alginate-chitosan (GCAC) microcapsules that have potential for live cell therapy applications. This microcapsule system, consisting of an alginate core with a covalently cross-linked chitosan membrane, was formed via ionotropic gelation between calcium ions and alginate, followed by chitosan coating by polyelectrolyte complexation and covalent cross-linking of chitosan by naturally derived genipin. Results showed that, using this design concept and the three-step procedure, spherical GCAC microcapsules with improved membrane strength, suppressed capsular swelling, and suitable permeability can be prepared. The suitability of this novel membrane formulation for live cell encapsulation was evaluated, using bacterial Lactobacillus plantarum 80 (pCBH1) (LP80) and mammalian HepG2 as model cells. Results showed that capsular integrity and bacterial cell viability were sustained 6 mo postenca...
Excess cholesterol is associated with cardiovascular diseases (CVD), an important cause of mortal... more 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. Bacterial cell viability (cfu/mL) L. reuteri NCIMB 11951 L. reuteri NCIMB 701359 L. reuteri NCIMB 702655 L. reuteri NCIMB 701089 L. reuteri NCIMB 702656 L. rhamnosus ATCC 53103 GG L. plantarum ATCC 14917 L. fermentum NCIMB 5221 L. fermentum NCIMB 8829 L. fermentum NCIMB
The Journal of Clinical Endocrinology & Metabolism, 2013
Context: Low serum 25-hydroxyvitamin D is a risk factor for osteoporosis, cardiovascular disease,... more Context: Low serum 25-hydroxyvitamin D is a risk factor for osteoporosis, cardiovascular disease, diabetes, and cancer. Disruption of noncholesterol sterol absorption due to cholesterol-lowering therapies may result in reduced fat-soluble vitamin absorption.
Cholesterol is known to be a major risk factor for coronary heart disease (CHD). Current treatmen... more Cholesterol is known to be a major risk factor for coronary heart disease (CHD). Current treatments for elevated blood cholesterol include dietary management, regular exercise, and drug therapy with fibrates, bile acid sequestrants, and statins. Such therapies, however, are often suboptimal and carry a risk for serious side effects. This study shows that microencapsulated Lactobacillus plantarum 80 (pCBH1) cells can efficiently break down and remove bile acids, and establishes a basis for their use in lowering blood serum cholesterol. Results show that microencapsulated LP80 (pCBH1) is able to effectively break down the conjugated bile acids glycodeoxycholic acid (GDCA) and taurodeoxycholic acid (TDCA) with bile salt hydrolase (BSH) activities of 0.19 and 0.08 µmol DCA/mg CDW/h respectively. This article also summarizes the physiological interrelationship between bile acids and cholesterol and predicts the oral doses of microencapsulated Lactobacillus plantarum 80 (pCBH1) cells required for lowering cholesterol.
There has been rapid growth in research regarding the use of live bacterial cells for therapeutic... more There has been rapid growth in research regarding the use of live bacterial cells for therapeutic purposes. The recognition that these cells can be genetically engineered to synthesize products that have therapeutic potential has generated considerable interest and excitement among clinicians and health professionals. It is expected that a wide range of disease modifying substrates such as enzymes, hormones, antibodies, vaccines, and other genetic products will be used successfully and will impact upon health care substantially. However, a major limitation in the use of these bacterial cells is the complexity of delivering them to the correct target tissues. Oral delivery of live cells, lyophilized cells, and immobilized cells has been attempted but with limited success. Primarily, this is because bacterial cells are incapable of surviving passage through the gastrointestinal tract. In many occasions, when given orally, these cells have been found to provoke immunogenic responses that are undesirable. Recent studies show that these problems can be overcome by delivering live bacterial cells, such as genetically engineered cells, using artificial cell microcapsules. This review summarizes recent advances in the therapeutic use of live bacterial cells for therapy, discusses the principles of using artificial cells for the oral delivery of bacterial cells, outlines methods for preparing suitable artificial cells for this purpose, addresses potentials and limitations for their application in therapy, and provides insight for the future direction of this emergent and highly prospective technology.
This study investigated the use of microencapsulated bile salt hydrolase (BSH) overproducing Lact... more This study investigated the use of microencapsulated bile salt hydrolase (BSH) overproducing Lactobacillus plantarum 80 cells for oral delivery applications using a dynamic computer-controlled model simulating the human gastrointestinal (GI) tract. Bile salt deconjugation rates for microencapsulated BSH overproducing cells were 4.87 ± 0.28 μmol/g microcapsule/h towards glycoconjugates and 0.79 ± 0.15 μmol/g microcapsule/h towards tauroconjugates in the simulated intestine, a significant (P < .05) increase over microencapsulated wild-type cells. Microcapsules protected the encased cells in the simulated stomach prior to intestinal release, maintaining cell viability above 10 9 cfu/mL at pH 2.5 and 3.0 and above 10 6 cfu/mL at pH 2.0 after 2-hour residence times. In the simulated intestine, encased cell viability was maintained above 10 10 cfu/mL after 3, 6, and 12-hour residence times in bile concentrations up to 1.0%. Results show that microencapsulation has potential in the oral delivery of live BSH active bacterial cells. However, in vivo testing is required.
The treatment of chronic wounds poses a significant challenge for clinicians and patients alike. ... more The treatment of chronic wounds poses a significant challenge for clinicians and patients alike. Here we report design and preclinical efficacy of a novel nitric oxide gas (gNO)-producing probiotic patch for wound healing. Specifically, a wound healing patch using lactic acid bacteria in an adhesive gas permeable membrane has been designed and investigated for treating ischaemic and infected full-thickness dermal wounds in a New Zealand white rabbit model for ischaemic wound healing. Kaplan-Meier survival curves showed increased wound closure with gNO-producing patch-treated wounds over 21 days of therapy (log-rank P = 0·0225 and Wilcoxon P = 0·0113). Cox proportional hazard regression showed that gNO-producing patch-treated wounds were 2·52 times more likely to close compared with control patches (hazard P = 0·0375, score P = 0·032 and likelihood ratio P = 0·0355), and histological analysis showed improved wound healing in gNO-producing patch-treated animals. This study may provide an effective, safe and less costly alternative for treating chronic wounds.
Histopathology 37, 269±277 Conclusions: This study indicates that an acute induction of iNOS expr... more Histopathology 37, 269±277 Conclusions: This study indicates that an acute induction of iNOS expression occurs in the brain during CM. This occurs in a number of different cells types, and is increased in the acute phase of CM compared to cases recovering from coma. As NO may activate a number of secondary neuropathological mechanisms in the brain, including modulators of synaptic function, induction of iNOS expression in cerebral malaria may contribute to coma, seizures and death.
Despite the significant contribution of gastrointestinal diseases to the global disease burden an... more Despite the significant contribution of gastrointestinal diseases to the global disease burden and the increasing recognition of the role played by the intestinal microbiota in human health and disease states, conventional methods of exploring and collecting samples from the gastrointestinal tract remain invasive, resource intensive, and often unable to capture all the information contained in these heterogeneous samples. A new class of gastrointestinal sampling capsules is emerging in the literature, which contains the components required for an autonomous intra-luminal device and preserves the spatial and temporal information of the gastrointestinal samples. In this paper, we identify the primary design requirements for gastrointestinal sampling capsules, and we review the state-of-the-art for different components and functionalities. We also suggest two design concepts, and we highlight future directions for this class of biomedical devices.
Recent research and clinical evidence suggest that thalidomide could potentially be used to treat... more Recent research and clinical evidence suggest that thalidomide could potentially be used to treat inflammation associated with Crohn's disease. However, systemic side effects associated with large doses of this drug have limited its widespread use. Treatment with thalidomide would prove more efficacious if the drug could be delivered directly to target areas in the gut, thereby reducing systemic circulation. Microcapsule encapsulation could enable direct delivery of the drug. To assess the latter, we designed and tested drug-targeting release characteristics of alginate-poly-Llysine-alginate (APA) microcapsules in simulated gastrointestinal environments. The results show that APA capsules enabled delivery of thalidomide in the middle and distal portions of the small intestine. We also compared the APA membrane formulation with an earlier designed alginate chitosan (AC) membrane thalidomide formulation. The results show that both APA and AC capsules allow for successful delivery of thalidomide in the gut and could prove beneficial in the treatment of Crohn's disease. However, further research is required.
This review describes the antimicrobial properties of nitric oxide (NO) and its application as an... more This review describes the antimicrobial properties of nitric oxide (NO) and its application as an antimicrobial agent in different formulations and medical devices. We depict the eukaryotic biosynthesis of NO and its physiologic functions as a cell messenger and as an antimicrobial agent of the cell-mediated immune response. We analyze the antimicrobial activity of NO and the eukaryotic protective mechanisms against NO for the purpose of delineating the therapeutic NO dosage range required for an efficacious and safe antimicrobial activity. We also examine the role of NO produced by virulent bacteria in lessening the efficacy of traditional antimicrobials. In addition, we discuss the efficacy of NO in the healing of infected wounds, describing different NO-producing devices by category, analyzing therapeutic levels, duration of NO production, as well as commercial considerations. Finally, we provide current and future prospects for the design and use of NO-producing devices.
Journal of pharmacy & pharmaceutical sciences : a publication of the Canadian Society for Pharmaceutical Sciences, Société canadienne des sciences pharmaceutiques, Jan 24, 2004
Bacterial cells can be engineered to synthesize a wide array of disease modifying substrates such... more Bacterial cells can be engineered to synthesize a wide array of disease modifying substrates such as cytokines, vaccines and antibodies; however, their use as an orally delivered therapeutic is limited by poor gastrointestinal (GI) survival and instigation of immunogenic response. Artificial cell microcapsules have been well studied as a means to overcome such problems, however, presently obtainable microcapsules have limitations. This study summarizes a novel microcapsule design specifying its preparation and GI stability in-vitro. Multilayer APPPA microcapsules were designed, prepared and characterized in-vitro for bacterial cell oral delivery using Lactobacillus reuteri cells as a model. Microcapsule structural integrity, mechanical stability, and GI survival studies were performed in simulated gastric (SGF) and intestinal (SIF) fluids in various pH conditions at 37.2 degrees C and compared with presently available alginate/poly-l-lysine/alginate (APA) microcapsules. HPLC was use...
Several studies have reported limited or no reduction in serum cholesterol in response to probiot... more Several studies have reported limited or no reduction in serum cholesterol in response to probiotic formulations. Recently, probiotics have shown promise in treating metabolic disease due to improved strain selection and delivery technologies. The aim of the present study was to evaluate the cholesterol-lowering efficacy of a yoghurt formulation containing microencapsulated bile salt hydrolase (BSH)-active Lactobacillus reuteri NCIMB 30242, taken twice per d over 6 weeks, in hypercholesterolaemic adults. A total of 114 subjects completed this double-blind, placebo-controlled, randomised, parallel-arm, multi-centre study. This interventional study included a 2-week washout, 2-week run-in and 6-week treatment period. Subjects were randomised to consume either yoghurts containing microencapsulated L. reuteri NCIMB 30242 or placebo yoghurts. Over the intervention period, subjects consuming yoghurts containing microencapsulated L. reuteri NCIMB 30242 attained significant reductions in LD...
Regulatory toxicology and pharmacology : RTP, 2012
A significant number of human clinical trials have reported no adverse effects associated with co... more A significant number of human clinical trials have reported no adverse effects associated with consumption of Lactobacillus reuteri (L. reuteri). In the present study, the clinical safety and toxicology of oral ingestion of supplement capsules containing L. reuteri NCIMB 30242 was investigated. A randomized group of 131 subjects received a dose of 2.9×10⁹ CFU L. reuteri NCIMB 30242 capsules (n=67) or placebo capsules (n=64) twice daily for 9 weeks. Clinical chemistry and hematological parameters of safety were analyzed. The frequency, duration and intensity of adverse events (AE)s and clinical significance of safety parameters were recorded for both groups. No clinically significant differences between the probiotic capsule and placebo capsule treated groups were detected in either the blood clinical chemistry or hematology results. The frequency and intensity of AEs was similar in the two groups. These results demonstrate that administration of a twice daily dose of 2.9×10⁹ CFU was...
We performed an analysis to determine the importance of bile acid modification genes in the gut m... more We performed an analysis to determine the importance of bile acid modification genes in the gut microbiome of inflammatory bowel disease and type 2 diabetic patients. We used publicly available metagenomic datasets from the Human Microbiome Project and the MetaHIT consortium, and determined the abundance of bile salt hydrolase gene (bsh), 7 alpha-dehydroxylase gene (adh) and 7-alpha hydroxysteroid dehydrogenase gene (hsdh) in fecal bacteria in diseased populations of Crohn's disease (CD), Ulcerative Colitis (UC) and Type 2 diabetes mellitus (T2DM). Phylum level abundance analysis showed a significant reduction in Firmicute-derived bsh in UC and T2DM patients but not in CD patients, relative to healthy controls. Reduction of adh and hsdh genes was also seen in UC and T2DM patients, while an increase was observed in the CD population as compared to healthy controls. A further analysis of the bsh genes showed significant differences in the correlations of certain Firmicutes familie...
Cardiovascular diseases (CVD) are the leading cause of global mortality and morbidity. Current CV... more 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. 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. Numerous clinical stud...
This article describes the preparation and in vitro characterization of novel genipin cross-linke... more This article describes the preparation and in vitro characterization of novel genipin cross-linked alginate-chitosan (GCAC) microcapsules that have potential for live cell therapy applications. This microcapsule system, consisting of an alginate core with a covalently cross-linked chitosan membrane, was formed via ionotropic gelation between calcium ions and alginate, followed by chitosan coating by polyelectrolyte complexation and covalent cross-linking of chitosan by naturally derived genipin. Results showed that, using this design concept and the three-step procedure, spherical GCAC microcapsules with improved membrane strength, suppressed capsular swelling, and suitable permeability can be prepared. The suitability of this novel membrane formulation for live cell encapsulation was evaluated, using bacterial Lactobacillus plantarum 80 (pCBH1) (LP80) and mammalian HepG2 as model cells. Results showed that capsular integrity and bacterial cell viability were sustained 6 mo postenca...
Excess cholesterol is associated with cardiovascular diseases (CVD), an important cause of mortal... more 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. Bacterial cell viability (cfu/mL) L. reuteri NCIMB 11951 L. reuteri NCIMB 701359 L. reuteri NCIMB 702655 L. reuteri NCIMB 701089 L. reuteri NCIMB 702656 L. rhamnosus ATCC 53103 GG L. plantarum ATCC 14917 L. fermentum NCIMB 5221 L. fermentum NCIMB 8829 L. fermentum NCIMB
The Journal of Clinical Endocrinology & Metabolism, 2013
Context: Low serum 25-hydroxyvitamin D is a risk factor for osteoporosis, cardiovascular disease,... more Context: Low serum 25-hydroxyvitamin D is a risk factor for osteoporosis, cardiovascular disease, diabetes, and cancer. Disruption of noncholesterol sterol absorption due to cholesterol-lowering therapies may result in reduced fat-soluble vitamin absorption.
Cholesterol is known to be a major risk factor for coronary heart disease (CHD). Current treatmen... more Cholesterol is known to be a major risk factor for coronary heart disease (CHD). Current treatments for elevated blood cholesterol include dietary management, regular exercise, and drug therapy with fibrates, bile acid sequestrants, and statins. Such therapies, however, are often suboptimal and carry a risk for serious side effects. This study shows that microencapsulated Lactobacillus plantarum 80 (pCBH1) cells can efficiently break down and remove bile acids, and establishes a basis for their use in lowering blood serum cholesterol. Results show that microencapsulated LP80 (pCBH1) is able to effectively break down the conjugated bile acids glycodeoxycholic acid (GDCA) and taurodeoxycholic acid (TDCA) with bile salt hydrolase (BSH) activities of 0.19 and 0.08 µmol DCA/mg CDW/h respectively. This article also summarizes the physiological interrelationship between bile acids and cholesterol and predicts the oral doses of microencapsulated Lactobacillus plantarum 80 (pCBH1) cells required for lowering cholesterol.
There has been rapid growth in research regarding the use of live bacterial cells for therapeutic... more There has been rapid growth in research regarding the use of live bacterial cells for therapeutic purposes. The recognition that these cells can be genetically engineered to synthesize products that have therapeutic potential has generated considerable interest and excitement among clinicians and health professionals. It is expected that a wide range of disease modifying substrates such as enzymes, hormones, antibodies, vaccines, and other genetic products will be used successfully and will impact upon health care substantially. However, a major limitation in the use of these bacterial cells is the complexity of delivering them to the correct target tissues. Oral delivery of live cells, lyophilized cells, and immobilized cells has been attempted but with limited success. Primarily, this is because bacterial cells are incapable of surviving passage through the gastrointestinal tract. In many occasions, when given orally, these cells have been found to provoke immunogenic responses that are undesirable. Recent studies show that these problems can be overcome by delivering live bacterial cells, such as genetically engineered cells, using artificial cell microcapsules. This review summarizes recent advances in the therapeutic use of live bacterial cells for therapy, discusses the principles of using artificial cells for the oral delivery of bacterial cells, outlines methods for preparing suitable artificial cells for this purpose, addresses potentials and limitations for their application in therapy, and provides insight for the future direction of this emergent and highly prospective technology.
This study investigated the use of microencapsulated bile salt hydrolase (BSH) overproducing Lact... more This study investigated the use of microencapsulated bile salt hydrolase (BSH) overproducing Lactobacillus plantarum 80 cells for oral delivery applications using a dynamic computer-controlled model simulating the human gastrointestinal (GI) tract. Bile salt deconjugation rates for microencapsulated BSH overproducing cells were 4.87 ± 0.28 μmol/g microcapsule/h towards glycoconjugates and 0.79 ± 0.15 μmol/g microcapsule/h towards tauroconjugates in the simulated intestine, a significant (P < .05) increase over microencapsulated wild-type cells. Microcapsules protected the encased cells in the simulated stomach prior to intestinal release, maintaining cell viability above 10 9 cfu/mL at pH 2.5 and 3.0 and above 10 6 cfu/mL at pH 2.0 after 2-hour residence times. In the simulated intestine, encased cell viability was maintained above 10 10 cfu/mL after 3, 6, and 12-hour residence times in bile concentrations up to 1.0%. Results show that microencapsulation has potential in the oral delivery of live BSH active bacterial cells. However, in vivo testing is required.
The treatment of chronic wounds poses a significant challenge for clinicians and patients alike. ... more The treatment of chronic wounds poses a significant challenge for clinicians and patients alike. Here we report design and preclinical efficacy of a novel nitric oxide gas (gNO)-producing probiotic patch for wound healing. Specifically, a wound healing patch using lactic acid bacteria in an adhesive gas permeable membrane has been designed and investigated for treating ischaemic and infected full-thickness dermal wounds in a New Zealand white rabbit model for ischaemic wound healing. Kaplan-Meier survival curves showed increased wound closure with gNO-producing patch-treated wounds over 21 days of therapy (log-rank P = 0·0225 and Wilcoxon P = 0·0113). Cox proportional hazard regression showed that gNO-producing patch-treated wounds were 2·52 times more likely to close compared with control patches (hazard P = 0·0375, score P = 0·032 and likelihood ratio P = 0·0355), and histological analysis showed improved wound healing in gNO-producing patch-treated animals. This study may provide an effective, safe and less costly alternative for treating chronic wounds.
Histopathology 37, 269±277 Conclusions: This study indicates that an acute induction of iNOS expr... more Histopathology 37, 269±277 Conclusions: This study indicates that an acute induction of iNOS expression occurs in the brain during CM. This occurs in a number of different cells types, and is increased in the acute phase of CM compared to cases recovering from coma. As NO may activate a number of secondary neuropathological mechanisms in the brain, including modulators of synaptic function, induction of iNOS expression in cerebral malaria may contribute to coma, seizures and death.
Despite the significant contribution of gastrointestinal diseases to the global disease burden an... more Despite the significant contribution of gastrointestinal diseases to the global disease burden and the increasing recognition of the role played by the intestinal microbiota in human health and disease states, conventional methods of exploring and collecting samples from the gastrointestinal tract remain invasive, resource intensive, and often unable to capture all the information contained in these heterogeneous samples. A new class of gastrointestinal sampling capsules is emerging in the literature, which contains the components required for an autonomous intra-luminal device and preserves the spatial and temporal information of the gastrointestinal samples. In this paper, we identify the primary design requirements for gastrointestinal sampling capsules, and we review the state-of-the-art for different components and functionalities. We also suggest two design concepts, and we highlight future directions for this class of biomedical devices.
Recent research and clinical evidence suggest that thalidomide could potentially be used to treat... more Recent research and clinical evidence suggest that thalidomide could potentially be used to treat inflammation associated with Crohn's disease. However, systemic side effects associated with large doses of this drug have limited its widespread use. Treatment with thalidomide would prove more efficacious if the drug could be delivered directly to target areas in the gut, thereby reducing systemic circulation. Microcapsule encapsulation could enable direct delivery of the drug. To assess the latter, we designed and tested drug-targeting release characteristics of alginate-poly-Llysine-alginate (APA) microcapsules in simulated gastrointestinal environments. The results show that APA capsules enabled delivery of thalidomide in the middle and distal portions of the small intestine. We also compared the APA membrane formulation with an earlier designed alginate chitosan (AC) membrane thalidomide formulation. The results show that both APA and AC capsules allow for successful delivery of thalidomide in the gut and could prove beneficial in the treatment of Crohn's disease. However, further research is required.
This review describes the antimicrobial properties of nitric oxide (NO) and its application as an... more This review describes the antimicrobial properties of nitric oxide (NO) and its application as an antimicrobial agent in different formulations and medical devices. We depict the eukaryotic biosynthesis of NO and its physiologic functions as a cell messenger and as an antimicrobial agent of the cell-mediated immune response. We analyze the antimicrobial activity of NO and the eukaryotic protective mechanisms against NO for the purpose of delineating the therapeutic NO dosage range required for an efficacious and safe antimicrobial activity. We also examine the role of NO produced by virulent bacteria in lessening the efficacy of traditional antimicrobials. In addition, we discuss the efficacy of NO in the healing of infected wounds, describing different NO-producing devices by category, analyzing therapeutic levels, duration of NO production, as well as commercial considerations. Finally, we provide current and future prospects for the design and use of NO-producing devices.
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Papers by Mitchell Jones