In situ bioprinting of double network anti-digestive xanthan gum derived hydrogel scaffolds for the treatment of enterocutaneous fistulas.

The clinical treatment of enterocutaneous fistula is challenging and causes significant patient discomfort. Fibrin gel can be used to seal tubular enterocutaneous fistulas, but it has low strength and poor digestion resistance. Based on in situ bioprinting and the anti-digestive properties of xanthan gum (XG), we used carboxymethyl chitosan (CMC) and xanthan gum modified by grafted glycidyl methacrylate (GMA) and aldehyde (GCX) as the ink to print a double network hydrogel that exhibited high strength and an excellent anti-digestive performance. In addition, in vitro studies confirmed the biocompatibility, degradability, and self-healing of hydrogels. In our rabbit tubular enterocutaneous fistula model, the in situ printed hydrogel resisted corrosion due to the intestinal fluid and acted as a scaffold for intestinal mucosal cells to proliferate on its surface. To summarize, in situ bioprinting GCX/CMC double network hydrogel can effectively block tubular enterocutaneous fistulas and provide a stable scaffold for intestinal mucosal regeneration.

Mucoadhesive gellan gum-based and carboxymethyl cellulose -based hydrogels containing gemcitabine and papain for bladder cancer treatment.

Local treatment of bladder cancer faces several limitations such as short residence time or low permeation through urothelium tissue. The aim of this work was to develop patient-friendly mucoadhesive gel formulations combining gemcitabine and the enzyme papain for improved intravesical chemotherapy delivery. Hydrogels based on two different polysaccharides, gellan gum and sodium carboxymethylcellulose (CMC), were prepared with either native papain or papain nanoparticles (nanopapain) to explore for the first time their use as permeability enhancers through bladder tissue. Gel formulations were characterized regarding enzyme stability, rheological behavior, retention on bladder tissue and bioadhesion, drug release properties, permeation capacity, and biocompatibility. After 90 days of storage, the enzyme loaded in the CMC gels retained up to 83.5 ± 4.9 % of its activity in the absence of the drug, and up to 78.1 ± 5.3 with gemcitabine. The gels were mucoadhesive and the enzyme papain showed mucolytic action, which resulted in resistance against washing off from the urothelium and enhanced permeability of gemcitabine in the ex vivo tissue diffusion tests. Native papain shortened lag-time tissue penetration to 0.6 h and enhanced 2-fold drug permeability All formulations demonstrated pseudoplastic behavior and no irritability. Overall, the developed formulations have potential as an upgraded alternative to intravesical therapy for bladder cancer treatment.

Sulfated galactoglucan impedes xenografted lung cancer cell growth by blocking angiogenesis via binding BMPRs.

Evidences propound tumor growth may be impeded by blocking angiogenesis. Before we showed that sulfated glucan or arabinogalactan might bind to BMP2 or its receptors to inhibit angiogenesis. Whether sulfated galactoglucan can target both BMPRIA and BMPRII to impede angiogenesis and tumor cells growth is still vague. Here, we prepare galactoglucan and its sulfated derivatives Sul-CDA-0.05. The sulfate groups substituted are at the C-6 of 1, 4-linked α-Glcp and 1, 4-linked α-Galp backbone and at the C-6 of branch chain T-linked α-Glcp. Sul-CDA-0.05 can inhibit angiogenesis in vitro and in vivo. Indeed, Sul-CDA-0.05 impedes xenografted A549 lung tumor cells growth. Mechanism study demonstrates that this polysaccharide may target both BMPRIA and BMPRII to block BMP/Smad/Id1 signaling and attenuate VEGF and its transcription factor. Our evidences suggest that Sul-CDA-0.05 may be a new drug candidate for anti-lung cancer therapy by targeting both BMPRIA and BMPRII.

An injectable gellan gum-based hydrogel that inhibits Staphylococcus aureus for infected bone defect repair.

The treatment of infected bone defects in complex anatomical structures, such as oral and maxillofacial structures, remains an intractable clinical challenge. Therefore, advanced biomaterials that have excellent anti-infection activity and allow convenient delivery are needed. We fabricated an innovative injectable gellan gum (GG)-based hydrogel loaded with nanohydroxyapatite particles and chlorhexidine (nHA/CHX). The hydrogel has a porous morphology, suitable swelling ratio, and good biocompatibility. It exerts strong antibacterial activity against Staphylococcus aureus growth and biofilm formation in vitro. We successfully established an infected calvarial defect rat model. Bacterial colony numbers were significantly lower in tissues surrounding the bone in rats of the GG/nHA/CHX group after debride surgery and hydrogel implantation in the defect regions than in rats of the blank group. Rats in the GG/nHA/CHX group exhibited significantly increased new bone formation compared to those in the blank group at 4 and 8 weeks. These findings indicate that gellan gum-based hydrogel with nHA/CHX can accelerate the repair of infected bone defects.

Exopolysaccharides from Klebsiella oxytoca: anti-inflammatory activity

Abstract Exopolysaccharides (EPS) produced by Klebsiella oxytoca are of environmental, pharmaceutical, and medicinal interest. However, studies about the anti-inflammatory activity of EPS produced by this microorganism still remain limited. The aim of this study was to produce, characterize, and evaluate the anti-inflammatory activity of EPS from K. oxytoca in a pleurisy model. Colorimetric analysis revealed that precipitated crude exopolysaccharides (KEPSC) and deproteinated exopolysaccharides (KEPS) present high levels of total carbohydrates (65.57% and 62.82%, respectively). Analyses of uronic acid (7.90% in KEPSC and 6.21% in KEPS) and pyruvic acid (3.01% in KEPSC and 1.68% in KEPS) confirm that the EPS are acidic. Gas chromatography-mass spectrometry analyses demonstrated that the EPS consisted of rhamnose (29.83%), glucose (11.21%), galactose (52.45%), and mannose (6.50%). The treatment of an experimental pleurisy model in rats through subcutaneous administration of 50, 100, 200, and 400 mg/kg of KEPS decreased both the volume of inflammatory exudate and the number of leukocytes recruited to the pleural cavity. The present data showed that EPS production by K. oxytoca using the method described is easy to perform and results in a good yield. In addition, we show that KEPS exhibit anti-inflammatory activity when administered subcutaneously in rats.

Effects of silver nanoparticles-polysaccharide on bleomycin-induced pulmonary fibrosis in rats.

OBJECTIVES: The first goal of this study was to synthesize the silver nanoparticles Alcaligenes xylosoxidans exopolysaccharide (Ag-AXEPS). The second objective was to analyse the role of Ag-AXEPS nanoparticles (NPS) in treating bleomycin (BLM)-induced lung fibrosis. METHODS: Intratracheal bleomycin (2.5 U/kg) was administered to prompt pulmonary fibrosis in rats, and pulmonary fibrosis was treated with Ag-AXEPS nanoparticles (100 ppm/twice a week for four weeks). KEY FINDINGS: Ag-AXEPS nanoparticles significantly decreased the diversity of pulmonary inflammatory agents in rats with BLM-induced fibrosis. Reduced levels of respiratory tumor necrosis factor-alpha, monocyte chemotactic protein-1, matrix metalloproteinases (MMP-2 and MMP-9) were observed on treatment with synthesized Ag-AXEPS. Similarly, the treatment decreased IL-12, mRNA levels of BAX and plasma fibrosis markers like N-terminal procollagen III propeptide and transforming growth factor-ß1. On the other hand, the treatment increased mRNA BCL2 and total antioxidant capacity. It also lowered the level of fibrosis, as was shown by a quantified pathologic study of hematoxylin-eosin-stained lung parts. The treatment, however, ensured that lung collagen was restored, as assessed by Masson's trichrome stain, and that overall survival was increased and enhanced. CONCLUSIONS: Our work showed that nanoparticles could be obtained at 37°C and may be a possible pulmonary fibrosis therapeutic agent.

Effect of Intake of Food Hydrocolloids of Bacterial Origin on the Glycemic Response in Humans: Systematic Review and Narrative Synthesis.

Diabetes mellitus is a chronic condition characterized by increased blood glucose levels from dysfunctional carbohydrate metabolism. Dietary intervention can help to prevent and manage the disease. Food hydrocolloids have been shown to have favorable properties in relation to glycaemic regulation. However, the use of food hydrocolloids of bacterial origin to modulate glucose responses is much less explored than other types of hydrocolloids. We, therefore, carried out the first review examining the impact of intake of food hydrocolloids of bacterial origin (as a direct supplement or incorporated into foods) on glycemic response in humans. Fourteen studies met the inclusion criteria. They used either xanthan gum, pullulan, or dextran as interventions. There was a wide variation in the amount of hydrocolloid supplementation provided and methods of preparation. Postprandial blood glucose responses were reduced in half of the studies, particularly at higher intake levels and longer chain hydrocolloids. When xanthan gum was added to the cooking process of muffins and rice, a significant reduction in postprandial blood glucose was observed. The use of these hydrocolloids is potentially effective though more research is needed in this area.

Strategies for Using Muramyl Peptides - Modulators of Innate Immunity of Bacterial Origin - in Medicine.

The spread of infectious diseases is rampant. The emergence of new infections, the irrational use of antibiotics in medicine and their widespread use in agriculture contribute to the emergence of microorganisms that are resistant to antimicrobial drugs. By 2050, mortality from antibiotic-resistant strains of bacteria is projected to increase up to 10 million people per year, which will exceed mortality from cancer. Mutations in bacteria and viruses are occurring faster than new drugs and vaccines are being introduced to the market. In search of effective protection against infections, new strategies and approaches are being developed, one of which is the use of innate immunity activators in combination with etiotropic chemotherapy drugs. Muramyl peptides, which are part of peptidoglycan of cell walls of all known bacteria, regularly formed in the body during the breakdown of microflora and considered to be natural regulators of immunity. Their interaction with intracellular receptors launches a sequence of processes that ultimately leads to the increased expression of genes of MHC molecules, pro-inflammatory mediators, cytokines and their soluble and membrane-associated receptors. As a result, all subpopulations of immunocompetent cells are activated: macrophages and dendritic cells, neutrophils, T-, B- lymphocytes and natural killer cells for an adequate response to foreign or transformed antigens, manifested both in the regulation of the inflammatory response and in providing immunological tolerance. Muramyl peptides take part in the process of hematopoiesis, stimulating production of colony-stimulating factors, which is the basis for their use in the treatment of oncological diseases. In this review we highlight clinical trials of drugs based on muramyl peptides, as well as clinical efficacy of drugs mifamurtide, lycopid, liasten and polimuramil. Such a multifactorial effect of muramyl peptides and a well-known mechanism of activity make them promising drugs in the treatment and preventing of infectious, allergic and oncological diseases, and in the composition of vaccines.

Structural characterization and hepatoprotective activity of a galactoglucan from Poria cocos.

To find the polysaccharide with hepatoprotective activity from Poria cocos and clarify its structure, a galactoglucan (PCP-1C) with a molecular weight of 17 kDa was purified from the Poria cocos sclerotium by column chromatography and activity evaluation in the present work. It was composed of galactose, glucose, mannose, and fucose in a molar percentage of 43.5: 24.4: 17.4: 14.6. Structural characterization showed that PCP-1C has a backbone consisted of 1,6-α-D-Galp, which branches composed of 1,3-ß-D-Glcp, 1,4-ß-D-Glcp, 1,6-ß-D-Glcp, T-ß-D-Glcp, T-α-D-Manp, T-α-L-Fucp and 1,3-α-L-Fucp. In vivo experiments found that PCP-1C can apparently improve the damage of liver tissue in CCl4-treated mice and relieve oxidative stress and inflammation. PCP-1C also reduced the expression of CAR and CYP2E1 in the liver. These findings indicated strong hepatoprotective effect of PCP-1C, which was attributed to the reduction of CCl4 metabolism via inhibiting the CAR/CYP2E1 signal pathway.

Contributions of exopolysaccharides from lactic acid bacteria as biotechnological tools in food, pharmaceutical, and medical applications.

Exopolysaccharides (EPS) are important bioproducts produced by some genera of lactic acid bacteria. EPS are famous for their shelf-life improving properties, techno-functional enhancing abilities in food and dairy industries, besides their beneficial health effects. Furthermore, exopolysaccharides have many prospective and well-established contributions in the field of drugs and diagnostic industry. In this review, classification of EPS produced by LAB was presented. Moreover, current and potential applications of EPS in food, dairy, baking industries, cereal-based, and functional products were described. Also, some clinical and pharmaceutical applications of EPS such as intelligent drug delivery systems (microsystems and nanosystems for sustained delivery), interpenetrating polymer networks (IPNs), anticancer drug-targeting, recombinant macromolecular biopharmaceuticals, gene delivery, tissue engineering, and role of EPS in diagnostics were highlighted. Finally, future prospects concerning enhancing EPS production, minimizing costs of their production, and exploring their contribution in further applications were discussed.

Potential of Exopolysaccharide from Porphyridium marinum to Contend with Bacterial Proliferation, Biofilm Formation, and Breast Cancer.

Exopolysaccharide (EPS) from marine microalgae are promising sources of a new generation of drugs. However, lot of them remain to be discovered and tested. In this study, EPS produced by Porphyridium marinum and its oligomers prepared by High Pressure Homogenizer have been tested for different biological activities, i.e., antibacterial, anti-fungal and antibiofilm activities on Candida albicans, as well as for their effects on the viability of murine breast cancer cells. Results have shown that all EPS samples present some biological activity. For antibacterial and antibiofilm activities, the native EPS exhibited a better efficiency with Minimum Inhibitory Concentration (MIC) from 62.5 µg/mL to 1000 µg/mL depending on the bacterial strain. For Candida albicans, the biofilm formation was reduced by about 90% by using only a 31.3 µg/mL concentration. Concerning breast cancer cells, lower molar masses fractions appeared to be more efficient, with a reduction of viability of up to 55%. Finally, analyses of polymers composition and viscosity measurements were conducted on all samples, in order to propose hypotheses involving the activities caused by the intrinsic properties of polymers.

The anti-cancer effects and mechanisms of lactic acid bacteria exopolysaccharides in vitro: A review.

Probiotic lactic acid bacteria (LAB) are a particular group of gram-positive bacteria that are usually involved in natural ferments and widely used in food manufacture industry. Most of them can produce exopolysaccharides (EPS), surface carbohydrate polymers with diverse biological functions. LAB EPS are potentially complementary and alternative medicines against cancer. EPS show anti-proliferative effects on a variety of tumor cells from intestine, liver, breast, etc. They modulate the development of tumors through various mechanisms including promoting apoptosis, inducing cell cycle arrest as well as anti-mutagenic, anti-oxidative, anti-angiogenesis and anti-inflammatory effects. Bacterial origin, existence form, chemical structure, purity et al. are important factors affecting the anticancer effects of EPS. The future challenge lies in elucidating the precise structure-function relationship of LAB EPS. Besides, more in vivo studies and further clinical trials are indispensable to confirm the anticancer effects.

Use of Typhoid Vi-Polysaccharide Vaccine as a Vaccine Probe to Delineate Clinical Criteria for Typhoid Fever.

Blood cultures (BCs) detect an estimated 50% of typhoid fever cases. There is need for validated clinical criteria to define cases that are BC negative, both to help direct empiric antibiotic treatment and to better evaluate the magnitude of protection conferred by typhoid vaccines. To derive and validate a clinical rule for defining BC-negative typhoid fever, we assessed, in a cluster-randomized effectiveness trial of Vi-polysaccharide (ViPS) typhoid vaccine in Kolkata, India, 14,797 episodes of fever lasting at least 3 days during 4 years of comprehensive, BC-based surveillance of 70,865 persons. A recursive partitioning algorithm was used to develop a decision rule to predict BC-proven typhoid cases with a diagnostic specificity of 97-98%. To validate this rule as a definition for BC-negative typhoid fever, we assessed whether the rule defined culture-negative syndromes prevented by ViPS vaccine. In a training subset of individuals, we identified the following two rules: rule 1: patients aged < 15 years with prolonged fever accompanied by a measured body temperature ≥ 100°F, headache, and nausea; rule 2: patients aged ≥ 15 years with prolonged fever accompanied by nausea and palpable liver but without constipation. The adjusted protective efficacy of ViPS against clinical typhoid defined by these rules in persons aged ≥ 2 years in a separate validation subset was 33% (95% CI: 4-53%). We have defined and validated a clinical rule for predicting BC-negative typhoid fever using a novel vaccine probe approach. If validated in other settings, this rule may be useful to guide clinical care and to enhance typhoid vaccine evaluations.

Evaluation of a standardised Vi poly-l-lysine ELISA for serology of Vi capsular polysaccharide antibodies.

Typhoid vaccines based on protein-conjugated capsular Vi polysaccharide (TCVs) prevent typhoid in infants and young children. Analysis of the serum anti-Vi IgG response following immunisation against typhoid confirms the immunogenicity of TCVs and forms an important part of the pathway to licensing. Comparative studies could expedite the licencing process, and the availability of a standardised ELISA method alongside the 1st International Standard (IS) 16/138 for anti-typhoid capsular Vi polysaccharide IgG (human) will facilitate this process. To this end, a non-commercial ELISA based on a coat of Vi and poly-l-lysine (Vi-PLL ELISA) was evaluated by 10 laboratories. Eight serum samples, including IS 16/138, were tested in the standardised Vi-PLL ELISA (n = 10), a commercial Vi ELISA (n = 3) and a biotinylated Vi ELISA (n = 1). Valid estimates of potencies relative to IS 16/138 were obtained for all samples in the Vi-PLL ELISA and the commercial ELISA, with good repeatability and reproducibility evident from the study results and concordant estimates obtained by the two ELISA methods. The study demonstrates that the Vi-PLL ELISA can be used in clinical trial studies to determine the immunogenicity of TCVs.

Acupoint injection of Bacillus Calmette-Guerin polysaccharide nucleic acid for patients with chronic urticaria: A protocol for systematic review.

BACKGROUND: To investigate the efficacy and safety of acupoint injection of Bacillus Calmette-Guerin polysaccharide nucleic acid (BCG-PSN) in the treatment of chronic urticaria (CU). METHODS: The following databases will be searched from their inception: Medline, Embase, Pubmed, Web of Science, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure Database, China Biomedical Literature Database, China Science Journal Database, and Wanfang Database. All databases will be searched from the date of creation until October 2019. In addition, we will manually search the list of medical journals as a supplement. The scope of the search included randomized controlled clinical studies related to acupoint injection of BCG-PSN for CU. The primary outcome is the disease activity control. Secondary outcomes include response rate, adverse events, and recurrence rates. The Cochrane RevMan V5.3 Deviation Assessment Tool will be used to assess bias assessment risk, data integration risk, meta-analysis risk, and subgroup analysis risk (if conditions are met). The average difference, standard mean difference and binary data will be used to represent continuous results. RESULTS: This study will comprehensively review the existing evidence on the treatment of CU by acupoint injection of BCG-PSN. CONCLUSION: This systematic review will provide a judgment basis for the effectiveness and safety of acupoint injection of BCG-PSN in the treatment of CU. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42019139885.

The need & the issues related to new-generation typhoid conjugate vaccines in India.

The low- and middle-income countries bear the highest burden of typhoid fever in the world. India, along with other South Asian countries, has a significant incidence of typhoid fever among young children though there is a paucity of published data on community burden. In spite of the availability of Vi-polysaccharide (Vi-PS) and conjugated Vi-PS vaccines, these are not adequately utilized in India and in the neighbouring countries. To address many shortcomings of the unconjugated Vi-PS vaccines, typhoid conjugate vaccines (TCVs) are developed by conjugating Vi-PS with different carrier proteins. Three such vaccines using tetanus toxoid as a carrier protein are already licensed in India. Several other Vi-PS conjugates are currently in various stages of development. The current review provides an update on the existing and upcoming new TCVs along with a detailed discussion on the various issues involved with their clinical use and limitations.

Koi herpesvirus (KHV) and KHV disease (KHVD) - a recently updated overview.

Over the last years, there has been an enormous increase in the knowledge on koi herpesvirus (KHV), koi herpesvirus disease (KHVD), pathogenesis and virus variants. Different KHV lineages have clearly been identified, possible genomic changes during replication in different cell cultures at different temperatures but also in several hosts have been identified, a persistent stage of infection has been specified and it has been shown that infection with KHV is not host specific at all, but KHVD is. Additionally, it has been shown that it is possible to combat KHVD by immunization with inactivated and attenuated live vaccines using different delivery systems but also to benefit from alternative treatments with e.g. exopolysaccharids obtained from Arthrospira platensis.

Stopping the Unstoppable: Unconventional Methods to Prevent the Biofilm Growth.

Biofilms are consortia of microorganisms encased in extracellular matrix that protect cells from adverse conditions. A biofilm matrix is typically composed of extracellular DNA, cellulose and proteinaceous amyloid fibers. The matrix aids in adhesion to abiotic and biotic surface including medical devices and host tissues. The presence of biofilm makes bacteria more resilient and non-responsive to most current treatment regimes at disposal. Therefore, biofilm-associated infections are serious threat in hospital settings and pose a huge burden on economy. Inhibition of matrix components (cellulose and/or amyloid formation) has emerged as a lucrative alternative strategy to cure biofilm-related infections and combat antibiotic resistance. Here we review the current and emerging therapeutic interventions to mitigate persistent infections due to biofilms. The successful implementation of these interventions will have a huge impact on alleviating the current financial burden on healthcare services.

Spirulina extract enriched for Braun-type lipoprotein (Immulina®) for inhibition of 4T1 breast tumors' growth and metastasis.

Spirulina platensis extracts have exhibited considerable anti-cancer effects. To investigate the efficacy of the Spirulina extract enriched for Braun-type lipoprotein (Immulina®) for breast cancer treatment, 4T1 breast tumor-bearing mice were treated with 40 mg/kg Immulina® daily and the tumors' growth and metastasis were assessed. Also, CD4, CD8, and CD56 staining were performed to investigate the Immulina® effect on the immune cells' recruitment to the tumors by immunohistochemistry. Immulina® could significantly (P < 0.001) inhibit 4T1 breast tumors' growth. Immulina®-treated group exhibited a 63% decrease in the tumors' volume in comparison with control (P < 0.001). Also, Immulina® could significantly (P < 0.001) decrease metastatic burden at the vital organs as 68% and 61% decrease in the liver and lungs metastatic colonies were observed, respectively. Also, Immulina® could increase mean survival time of the tumor-bearing mice for 29 days. The Spirulina-treated mice tumors contained significantly more infiltrated NK, CD4+, and CD8+ T lymphocytes in comparison with control. Taking together, Immulina® can be a safe anti-cancer supplement with the ability to cause direct apoptosis to the cancer cells and activate the immune system against tumor. This supplement with natural origin seems to have bright future to help breast cancer patients.

Preparation of Calcipotriol Emulsion Using Bacterial Exopolysaccharides as Emulsifier for Percutaneous Treatment of Psoriasis Vulgaris.

An exopolysaccharides/calcipotriol (EPS/CPT) emulsion was prepared using bacterial EPS as emulsifier, sunflower oil as an oil phase and CPT as the loaded drug, and the effect of this emulsion on psoriasis vulgaris treatment was evaluated. An EPS composed of mannose (70.56%) and glucose (29.44%) was obtained from the marine mangrove bacteria Bacillus amyloliquefaciens ZWJ (Zhu Wenjing) strain. The EPS has significant emulsifying activity at the concentration of 1.5%. The prepared EPS/CPT emulsion has small and stable particle size, with a drug content of 0.00492%, and good spreading properties. The in vitro drug release results revealed that the emulsion showed a certain sustained release effect. In vitro and in vivo animal experiments show that the EPS/CPT emulsion can effectively treat psoriasis vulgaris by increasing the accumulation of CPT in psoriatic skin lesions and reducing the levels of inflammatory cells and inflammatory factors (TNF and IL6). Additionally, it has a certain effect on reducing the side effects associated with CPT. This study lays a foundation for the research of EPS in the topical application of medical materials and treatment of psoriasis.