BACKGROUND AND OBJECTIVE: Microbial selenium (Se) supplementation is an essential area of biotechnological research due to differences in the bioavailability and toxicity of different forms of selenium. To date, research has focused mainly on the use of selenized yeast. However, in recent years, scientific interest has also increased in other microorganisms, such as lactic acid bacteria (LAB), which have several unique properties that can affect the quality and bioavailability of selenium. LAB, unlike yeast, can also act as probiotics, which may bring additional health benefits related to improving the intestinal microbiota and supporting the health of the gastrointestinal tract. METHODS: This study investigates the in vitro bioaccessibility and bioavailability of Se from two lactic acid bacterial strains, Streptococcus thermophilus CCDM 144 and Enterococcus faecium CCDM 922 A. We evaluated Se accumulation, speciation, and stability during simulated gastrointestinal digestion and Se permeation through a Caco-2 cell monolayer model. RESULTS: Both strains accumulated Se, metabolizing it predominantly into selenium nanoparticles (SeNPs, 64-77 % of total Se), with only a minor fraction (<5 % of total Se) of organic Se species. Experiments revealed that while organic Se species had high bioavailability (up to 90 %), their bioaccessibility during digestion was very low (<0.1 % of total Se). In contrast, SeNPs showed high bioaccessibility (∼90 %) and moderate transport efficiency through the intestinal model (16-19 % after 4 hours). CONCLUSION: These results highlight the potential of SeNPs produced by lactic acid bacteria as a bioaccessible form of Se for dietary supplementation. Further research is required to explore the behavior of SeNPs within the human body to fully understand how they can be used safely and effectively in nutrition or other applications.
- MeSH
- Biological Availability * MeSH
- Models, Biological MeSH
- Caco-2 Cells MeSH
- Intestinal Barrier Function MeSH
- Lactobacillales metabolism MeSH
- Humans MeSH
- Permeability MeSH
- Selenium * metabolism MeSH
- Streptococcus thermophilus metabolism MeSH
- Digestion MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Nanoparticles have drawn significant interest in a range of applications, ranging from biomedical to environmental sciences, due to their distinctive physicochemical characteristics. In this study, it was reported that simple biological production of Ag, Se, and bimetallic Ag2Se nanoparticles (NPs) with Pseudomonas aeruginosa is a promising, low-cost, and environmentally friendly method. For the first time in the scientific literature, Ag2Se nanoparticles have been generated via green bacterial biosynthesis. UV-vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and EDX were used to characterize the produced NPs. Biosynthesized NPs were examined for antibacterial, antibiofilm, and photocatalytic properties, and it was determined that the effects of NPs were dose dependent. The biosynthesized AgNPs, SeNPs, and Ag2Se NPs showed anti-microbial activity against Escherichia coli and Staphylococcus aureus. Minimal inhibitory concentrations (MICs) of E. coli and S. aureus were between 150 and 250 μg/mL. The NPs showed antibiofilm activity against E. coli and S. aureus at sub-MIC levels and reduced biofilm formation by at least 80% at a concentration of 200 μg/mL of each NPs. To photocatalyze the breakdown of Congo red, Ag, Se, and Ag2Se NPs were utilized, and their photocatalytic activity was tested at various concentrations and intervals. A minor decrease of photocatalytic degradation was detected throughout the NPs reuse operation (five cycles). Based on the encouraging findings, the synthesized NPs demonstrated antibacterial, antibiofilm, and photocatalytic properties, suggesting that they might be used in pharmaceutical, medical, environmental, and other applications.
- MeSH
- Anti-Bacterial Agents * pharmacology chemistry chemical synthesis MeSH
- Biofilms * drug effects MeSH
- Escherichia coli * drug effects MeSH
- Catalysis MeSH
- Metal Nanoparticles * chemistry MeSH
- Microbial Sensitivity Tests * MeSH
- Pseudomonas aeruginosa * drug effects metabolism MeSH
- Selenium chemistry pharmacology MeSH
- Silver Compounds chemistry pharmacology MeSH
- Staphylococcus aureus * drug effects MeSH
- Silver * chemistry pharmacology metabolism MeSH
- Green Chemistry Technology * MeSH
- Publication type
- Journal Article MeSH
Závěrečná zpráva o řešení grantu Agentury pro zdravotnický výzkum MZ ČR
nestr.
Nárůst rezistence mikroorganismů je současný celosvětový problém nejen u hospitalizovaných pacientů, ale také u pacientů léčených ambulantně. Je proto nutné hledat terapeutické alternativy, které by mohly snížit selekční tlak antibiotik na dané mikroorganismy a zvýšily by šanci na jejich eradikaci. V současné době se dostávají do popředí zájmu ve wound managementu i v lokálním podání přírodní produkty. Jedním z velmi nadějných materiálů je přírodní pryskyřice Gum Karaya (GK), která na základě našich předběžných výsledků splňuje současné požadavky na dočasný kryt ran (podpora epitelizace, antimikrobiální aktivita, absorpce exudátu aj.). V projektu se zaměříme na moderní přístup k hojení infikované rány, kdy využijeme pryskyřici GK v různých formách (hydrogel, porézní film a vlákenný kryt) na řízené uvolňování antibakteriálních biogenních systémů (bakteriofágů, antibakteriálních proteinů a nanočástic) zaměřených proti multirezistentním kmenům bakterií. Účinnost krytů vůči bakteriím bude testována preklinicky na animálním modelu prasete.; The increase in resistance of microorganisms is a current worldwide problem, not only in hospitalized patients, but also in patients treated on an outpatient basis. Therefore, it is necessary to look for innovative therapeutic alternatives that could reduce antibiotic selection pressure on given microorganisms and increase chances of their eradication. Currently, at the forefront of interest in wound management and local application are natural products. Based on our preliminary experiments, one of the most promising materials that meets modern requirements for temporal dressing (epithelialization support, antimicrobial activity, exudate absorption etc.) is undoubtedly Gum Karaya (GK). In the project, we will focus on a modern approach to wound healing by using GK in different forms (hydrogel, porous film, fiber dressing) to control antibacterial biogenic system release (bacteriophages, antibacterial proteins and nanoparticles) targeted at multidrug resistant bacterial strains. Dressing efficacy against bacteria will be evaluated preclinically on pig animal model.
- Keywords
- Bakteriofágy, Bacteriophages, antimikrobiální peptidy, antimicrobial peptides, fágy, phages, Biopolymerní hydrogel, Multirezistentní kmeny bakterií, Komplikovaná infekce kůže a měkkých tkání, Nanočástice selenu, Biopolymer hyrogel, Multidrug-resistant bacterial strains, Complicated skin and soft tissue infection, Selenium nanoparticles,
- NML Publication type
- závěrečné zprávy o řešení grantu AZV MZ ČR
In this study, we tested the ability of lactobacilli and bifidobacteria strains to accumulate and biotransform sodium selenite into various selenium species, including selenium nanoparticles (SeNPs). Selenium tolerance and cytotoxicity of selenized strains towards human adenocarcinoma Caco-2 and HT29 cells were determined for all tested strains. Furthermore, the influence of selenium enrichment on the antioxidant activity of selenized strains and hydrophobicity of the bacterial cell surfaces were evaluated. Both hydrophobicity and antioxidant activity increased significantly in the selenized L. paracasei strain and decreased significantly in the selenized L. helveticus strain. The concentrations of 5 and 10 mg/L Na2SeO3 in the growth media were safer for Caco-2 and HT29 cell growth than higher concentrations. At higher concentrations (30, 50, and 100 mg/L), the cell viability was reduced. All the tested strains showed differences in antioxidant potential and hydrophobicity after selenium enrichment. In addition to selenocystine and selenomethionine, the tested bacterial strains produced significant amounts of SeNPs. Our results show that the tested bacterial strains can accumulate and biotransform inorganic selenium, which allows them to become a potential source of selenium.
- MeSH
- Antioxidants MeSH
- Caco-2 Cells MeSH
- Lactobacillus metabolism MeSH
- Humans MeSH
- Dietary Supplements MeSH
- Selenium * metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
BACKGROUND AND OBJECTIVE: Yeasts have the remarkable capability to transform and integrate inorganic selenium into their cellular structures, thereby enhancing its bioavailability and reducing its toxicity. In recent years, yeasts have attracted attention as potential alternative sources of protein. METHODS: This study explores the selenium accumulation potential of two less explored yeast strains, namely the probiotic Saccharomyces boulardii CCDM 2020 and Pichia fermentas CCDM 2012, in comparison to the extensively studied Saccharomyces cerevisiae CCDM 272. Our investigation encompassed diverse stress conditions. Subsequently, the selenized yeasts were subjected to an INFOGEST gastrointestinal model. The adherence and hydrophobicity were determined with undigested cells RESULTS: Stress conditions had an important role in influencing the quantity and size of selenium nanoparticles (SeNPs) generated by the tested yeasts. Remarkably, SeMet synthesis was limited to Pichia fermentas CCDM 2012 and S. boulardii CCDM 2020, with S. cerevisiae CCDM 272 not displaying SeMet production at all. Throughout the simulated gastrointestinal digestion, the most substantial release of SeCys2, SeMet, and SeNPs from the selenized yeasts occurred during the intestinal phase. Notably, exception was found in strain CCDM 272, where the majority of particles were released during the oral phase. CONCLUSION: The utilization of both traditional and non-traditional selenized yeast types, harnessed for their noted functional attributes, holds potential for expanding the range of products available while enhancing their nutritional value and health benefits.
Selenium is an essential trace element that is crucial for cellular antioxidant defense against reactive oxygen species (ROS). Recently, many selenium-containing compounds have exhibited a wide spectrum of biological activities that make them promising scaffolds in Medicinal Chemistry, and, in particular, in the search for novel compounds with anticancer activity. Similarly, certain tellurium-containing compounds have also exhibited substantial biological activities. Here we provide an overview of the biological activities of seleno- and tellurocompounds including chemopreventive activity, antioxidant or pro-oxidant activity, modulation of the inflammatory processes, induction of apoptosis, modulation of autophagy, inhibition of multidrug efflux pumps such as P-gp, inhibition of cancer metastasis, selective targeting of tumors and enhancement of the cytotoxic activity of chemotherapeutic drugs, as well as overcoming tumor drug resistance. A review of the chemistry of the most relevant seleno- or tellurocompounds with activity against resistant cancers is also presented, paying attention to the synthesis of these compounds and to the preparation of bioactive selenium or tellurium nanoparticles. Based on these data, the use of these seleno- and tellurocompounds is a promising approach in the development of strategies that can drive forward the search for novel therapies or adjuvants of current therapies against drug-resistant cancers.
- MeSH
- Drug Resistance, Neoplasm MeSH
- Humans MeSH
- Drug Resistance, Multiple MeSH
- Neoplasms * drug therapy MeSH
- Nanoparticles * MeSH
- Antineoplastic Agents * chemistry pharmacology therapeutic use MeSH
- Reactive Oxygen Species MeSH
- Selenium * chemistry pharmacology therapeutic use MeSH
- Tellurium chemistry pharmacology therapeutic use MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
In a biological system, nanoparticles (NPs) may interact with biomolecules. Specifically, the adsorption of proteins on the nanoparticle surface may influence both the nanoparticles' and proteins' overall bio-reactivity. Nevertheless, our knowledge of the biocompatibility and risk of exposure to nanomaterials is limited. Here, in vitro and ex ovo biocompatibility of naturally based crosslinked freeze-dried 3D porous collagen/chitosan scaffolds, modified with thermostable fibroblast growth factor 2 (FGF2-STAB®), to enhance healing and selenium nanoparticles (SeNPs) to provide antibacterial activity, were evaluated. Biocompatibility and cytotoxicity were tested in vitro using normal human dermal fibroblasts (NHDF) with scaffolds and SeNPs and FGF2-STAB® solutions. Metabolic activity assays indicated an antagonistic effect of SeNPs and FGF2-STAB® at high concentrations of SeNPs. The half-maximal inhibitory concentration (IC50) of SeNPs for NHDF was 18.9 µg/ml and IC80 was 5.6 µg/ml. The angiogenic properties of the scaffolds were monitored ex ovo using a chick chorioallantoic membrane (CAM) assay and the cytotoxicity of SeNPs over IC80 value was confirmed. Furthermore, the positive effect of FGF2-STAB® at very low concentrations (0.01 µg/ml) on NHDF metabolic activity was observed. Based on detailed in vitro testing, the optimal concentrations of additives in the scaffolds were determined, specifically 1 µg/ml of FGF2-STAB® and 1 µg/ml of SeNPs. The scaffolds were further subjected to antimicrobial tests, where an increase in selenium concentration in the collagen/chitosan scaffolds increased the antibacterial activity. This work highlights the antimicrobial ability and biocompatibility of newly developed crosslinked collagen/chitosan scaffolds involving FGF2-STAB® and SeNPs. Moreover, we suggest that these sponges could be used as scaffolds for growing cells in systems with low mechanical loading in tissue engineering, especially in dermis replacement, where neovascularization is a crucial parameter for successful skin regeneration. Due to their antimicrobial properties, these scaffolds are also highly promising for tissue replacement requiring the prevention of infection.
- MeSH
- Anti-Bacterial Agents MeSH
- Biocompatible Materials pharmacology MeSH
- Cell Line MeSH
- Chitosan pharmacology MeSH
- Fibroblast Growth Factor 2 pharmacology MeSH
- Fibroblasts drug effects MeSH
- Wound Healing MeSH
- Collagen pharmacology MeSH
- Humans MeSH
- Nanoparticles chemistry therapeutic use MeSH
- Porosity MeSH
- Selenium chemistry pharmacology MeSH
- Materials Testing MeSH
- Tissue Engineering methods MeSH
- Tissue Scaffolds * MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
The selenium (Se) enrichment of yeasts and lactic acid bacteria (LAB) has recently emerged as a novel concept; the individual health effects of these beneficial microorganisms are combined by supplying the essential micronutrient Se in a more bioavailable and less toxic form. This study investigated the bioavailability of Se in the strains Enterococcus faecium CCDM 922A (EF) and Streptococcus thermophilus CCDM 144 (ST) and their respective Se-enriched forms, SeEF and SeST, in a CD (SD-Sprague Dawley) IGS rat model. Se-enriched LAB administration resulted in higher Se concentrations in the liver and kidneys of rats, where selenocystine was the prevalent Se species. The administration of both Se-enriched strains improved the antioxidant status of the animals. The effect of the diet was more pronounced in the heart tissue, where a lower glutathione reductase content was observed, irrespective of the Se fortification in LAB. Interestingly, rats fed diets with EF and SeEF had higher glutathione reductase activity. Reduced concentrations of serum malondialdehyde were noted following Se supplementation. Diets containing Se-enriched strains showed no macroscopic effects on the liver, kidneys, heart, and brain and had no apparent influence on the basic parameters of the lipid metabolism. Both the strains tested herein showed potential for further applications as promising sources of organically bound Se and Se nanoparticles.
- Publication type
- Journal Article MeSH
A highly porous scaffold is a desirable outcome in the field of tissue engineering. The porous structure mediates water-retaining properties that ensure good nutrient transportation as well as creates a suitable environment for cells. In this study, porous antibacterial collagenous scaffolds containing chitosan and selenium nanoparticles (SeNPs) as antibacterial agents were studied. The addition of antibacterial agents increased the application potential of the material for infected and chronic wounds. The morphology, swelling, biodegradation, and antibacterial activity of collagen-based scaffolds were characterized systematically to investigate the overall impact of the antibacterial additives. The additives visibly influenced the morphology, water‑retaining properties as well as the stability of the materials in the presence of collagenase enzymes. Even at concentrations as low as 5 ppm of SeNPs, modified polymeric scaffolds showed considerable inhibition activity towards Gram-positive bacterial strains such as Staphylococcus aureus and methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis in a dose-dependent manner.
- Publication type
- Journal Article MeSH
Nanotechnology, new fascinating field of science, is bringing many application's options. However, it is necessary to understand their potential environmental risk and toxicity. Zinc selenide quantum dots (ZnSe QDs) are getting valuable due to wide industrial usage, mainly as cadmium free diodes or stabilizing ligand. Thanks to unique properties, they could also open the possibilities of application in the agriculture. Their effects on living organisms, including plants, are still unknown. Therefore, the attention of this work was given to antioxidant response of Arabidopsis thaliana to 100 and 250 μM ZnSe QDs foliar feeding. ZnSe QDs treatment had no statistically significant differences in morphology but led to increased antioxidant response in the leaves at the level of gene expression and production secondary antioxidant metabolites. Concurrently, analysis of growth properties of Agrobacterium tumefaciens was done. 250 μM ZnSe solution inhibited the Agrobacterium tumefaciens viability by 60%. This is the first mention about effect ZnSe QDs on the plants. Although QDs induced oxidative stress, the apply treatment dose of ZnSe QDs did not have significant toxic effect on the plants and even no morphological changes were observed. However, the same amount of ZnSe QD induced an inhibitory effect on Agrobacterium tumefaciens.
- MeSH
- Agrobacterium tumefaciens drug effects growth & development MeSH
- Antioxidants metabolism MeSH
- Arabidopsis genetics growth & development metabolism MeSH
- Gene Expression * MeSH
- Quantum Dots toxicity MeSH
- Metabolomics * MeSH
- Selenium Compounds administration & dosage toxicity MeSH
- Zinc Compounds administration & dosage toxicity MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
