Styrene-maleic acid (SMA) and similar amphiphilic copolymers are known to cut biological membranes into lipid nanoparticles/nanodiscs containing membrane proteins apparently in their relatively native membrane lipid environment. Our previous work demonstrated that membrane raft microdomains resist such disintegration by SMA. The use of SMA in studying membrane proteins is limited by its heterogeneity and the inability to prepare defined derivatives. In the present paper, we demonstrate that some amphiphilic peptides structurally mimicking SMA also similarly disintegrate cell membranes. In contrast to the previously used copolymers, the simple peptides are structurally homogeneous. We found that their membrane-disintegrating activity increases with their length (reaching optimum at 24 amino acids) and requires a basic primary structure, that is, (XXD)n, where X represents a hydrophobic amino acid (optimally phenylalanine), D aspartic acid, and n is the number of repeats of these triplets. These peptides may provide opportunities for various well-defined potentially useful modifications in the study of membrane protein biochemistry. Our present results confirm a specific character of membrane raft microdomains.
- MeSH
- Cell Membrane metabolism chemistry MeSH
- Cell Line MeSH
- Humans MeSH
- Maleates chemistry MeSH
- Membrane Microdomains metabolism chemistry MeSH
- Membrane Proteins * chemistry metabolism MeSH
- Peptides * chemistry MeSH
- Polystyrenes chemistry MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
An advantageous alternative to the use of detergents in biochemical studies on membrane proteins are the recently developed styrene-maleic acid (SMA) amphipathic copolymers. In our recent study [1] we demonstrated that using this approach, most T cell membrane proteins were fully solubilized (presumably in small nanodiscs), while two types of raft proteins, GPI-anchored proteins and Src family kinases, were mostly present in much larger (>250 nm) membrane fragments markedly enriched in typical raft lipids, cholesterol and lipids containing saturated fatty acid residues. In the present study we demonstrate that disintegration of membranes of several other cell types by means of SMA copolymer follows a similar pattern and we provide a detailed proteomic and lipidomic characterization of these SMA-resistant membrane fragments (SRMs).
Malabsorpce žlučových kyselin (BAM – bile acid malabsorption) je výsledkem dysregulace enterohepatálního oběhu žlučových kyselin a jejich syntézy v játrech. Prevalence BAM je odhadována na 1 % všeobecné dospělé populace, patří mezi nejvíce opomíjené diagnózy. U osob splňujících diagnostická kritéria dráždivého tračníku se primární BAM vyskytuje u třetiny nemocných. U Crohnovy choroby s terminální ileitidou nebo po resekci terminálního ilea je BAM přítomna u 50–100 % pacientů. U onkologických pacientů s anamnézou radioterapie v oblasti pánve postihuje až polovinu nemocných. Zlatým standardem diagnostiky je SeHCAT test (75Selenium HomoCholic Acid Taurine test), nyní nově dostupný také v České republice. Hlavním dietním opatřením je omezení tuků v potravě. Základem farmakoterapie je podání sekvestrantů žlučových kyselin (v České republice je dostupný cholestyramin).
Bile acid malabsorption (BAM) is caused by dysregulation of enterohepatic circulation of bile acids and their synthesis in the liver. Estimated prevalence is about 1% of adult population. BAM has been substantially underdiagnosed. This condition can be present in one third of patients with diarrhoea-predominant irritable bowel syndrome and in 50–100% of Crohn‘s disease with ileitis or previously resected terminal ileum. Up to one half of oncology patients with pelvic radiotherapy suffer from BAM. SeHCAT test (75Selenium HomoCholic Acid Taurine test) is the gold diagnostic standard and the test has just become available in the Czech Republic. Low-fat diet is the most important dietary modification. Bile acids sequestrants (cholestyramine in the Czech Republic) are the crucial part of pharmacotherapy.
- Keywords
- SeHCAT test,
- MeSH
- Cholestyramine Resin MeSH
- Diagnosis, Differential MeSH
- Humans MeSH
- Malabsorption Syndromes * diagnosis classification therapy MeSH
- Neoplasms * complications MeSH
- Prevalence MeSH
- Bile Acids and Salts physiology metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
Hydrophobic fibrous slippery liquid-infused porous surfaces (SLIPS) were fabricated by electrospinning polydimethylsiloxane (PDMS) and polystyrene (PS) as a carrier polymer on plasma-treated polyethylene (PE) and polyurethane (PU) substrates. Subsequent infusion of blackseed oil (BSO) into the porous structures was applied for the preparation of the SLIPS. SLIPS with infused lubricants can act as a repellency layer and play an important role in the prevention of biofilm formation. The effect of polymer solutions used in the electrospinning process was investigated to obtain well-defined hydrophobic fibrous structures. The surface properties were analyzed through various optical, macroscopic and spectroscopic techniques. A comprehensive investigation of the surface chemistry, surface morphology/topography, and mechanical properties was carried out on selected samples at optimized conditions. The electrospun fibers prepared using a mixture of PDMS/PS in the ratio of 1:1:10 (g/g/mL) using tetrahydrofuran (THF) solvent showed the best results in terms of fiber uniformity. The subsequent infusion of BSO into the fabricated PDMS/PS fiber mats exhibited slippery behavior regarding water droplets. Moreover, prepared SLIPS exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli bacterium strains.
- MeSH
- Dimethylpolysiloxanes * MeSH
- Escherichia coli MeSH
- Polymers chemistry MeSH
- Polystyrenes * MeSH
- Porosity MeSH
- Publication type
- Journal Article MeSH
In this work, a novel cation exchange membrane, PSEBS SU22 was deployed in microbial fuel cells (MFCs) to examine system efficacy in line with membrane characteristics and inoculum source. It turned out that compared to a reference membrane (Nafion), employing PSEBS SU22 resulted in higher current density and electricity generation kinetics, while the electron recoveries were similar (19-28%). These outcomes indicated more beneficial ion transfer features and lower mass transfer-related losses in the PSEBS SU22-MFCs, supported by membrane water uptake, ion exchange capacity, ionic conductivity and permselectivity. By re-activating the membranes after (bio)foulant removal, PSEBS SU22 regained nearly its initial conductivity, highlighting a salient functional stability. Although the particular inoculum showed a clear effect on the microbial composition of the membrane biofouling layers, the dominance of aerobic species was revealed in all cases. Considering all the findings, the PSEBS SU22 seems to be promising for application in MFCs.
- MeSH
- Alkenes MeSH
- Biofouling * MeSH
- Electricity MeSH
- Electrodes MeSH
- Ethylenes MeSH
- Cations MeSH
- Polyethylene MeSH
- Polystyrenes MeSH
- Bioelectric Energy Sources * MeSH
- Publication type
- Journal Article MeSH
Photodynamic inactivation (PDI) is a promising approach for the efficient killing of pathogenic microbes. In this study, the photodynamic effect of sulfonated polystyrene nanoparticles with encapsulated hydrophobic 5,10,15,20-tetraphenylporphyrin (TPP-NP) photosensitizers on Gram-positive (including multi-resistant) and Gram-negative bacterial strains was investigated. The cell viability was determined by the colony forming unit method. The results showed no dark cytotoxicity but high phototoxicity within the tested conditions. Gram-positive bacteria were more sensitive to TPP-NPs than Gram-negative bacteria. Atomic force microscopy was used to detect changes in the morphological properties of bacteria before and after the PDI treatment.
- MeSH
- Bacteria drug effects radiation effects MeSH
- Photochemical Processes * MeSH
- Photochemotherapy methods MeSH
- Microscopy, Atomic Force MeSH
- Nanoparticles * chemistry MeSH
- Polystyrenes * chemistry MeSH
- Porphyrins administration & dosage chemistry MeSH
- Drug Compounding * MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The aim of our research was to study the behaviour of adipose tissue-derived stem cells (ADSCs) and vascular smooth muscle cells (VSMCs) on variously modified poly(L-lactide) (PLLA) foils, namely on pristine PLLA, plasma-treated PLLA, PLLA grafted with polyethylene glycol (PEG), PLLA grafted with dextran (Dex), and the tissue culture polystyrene (PS) control. On these materials, the ADSCs were biochemically differentiated towards VSMCs by a medium supplemented with TGFβ1, BMP4 and ascorbic acid (i.e. differentiation medium). ADSCs cultured in a non-differentiation medium were used as a negative control. Mature VSMCs cultured in both types of medium were used as a positive control. The impact of the variously modified PLLA foils and/or differences in the composition of the medium were studied with reference to cell adhesion, growth and differentiation. We observed similar adhesion and growth of ADSCs on all PLLA samples when they were cultured in the non-differentiation medium. The differentiation medium supported the expression of specific early, mid-term and/or late markers of differentiation (i.e. type I collagen, αSMA, calponin, smoothelin, and smooth muscle myosin heavy chain) in ADSCs on all tested samples. Moreover, ADSCs cultured in the differentiation medium revealed significant differences in cell growth among the samples that were similar to the differences observed in the cultures of VSMCs. The round morphology of the VSMCs indicated worse adhesion to pristine PLLA, and this sample was also characterized by the lowest cell proliferation. Culturing VSMCs in the differentiation medium inhibited their metabolic activity and reduced the cell numbers. Both cell types formed the most stable monolayer on plasma-treated PLLA and on the PS control. The behaviour of ADSCs and VSMCs on the tested PLLA foils differed according to the specific cell type and culture conditions. The suitable biocompatibility of both cell types on the tested PLLA foils seems to be favourable for vascular tissue engineering purposes.
- MeSH
- Aorta metabolism MeSH
- Biocompatible Materials MeSH
- Biopolymers chemistry MeSH
- Cell Adhesion MeSH
- Cell Differentiation drug effects MeSH
- Stem Cells cytology MeSH
- Microscopy, Atomic Force MeSH
- Myocytes, Smooth Muscle cytology MeSH
- Oxazines chemistry MeSH
- Polyesters chemistry MeSH
- Polymers chemistry MeSH
- Polysaccharides chemistry MeSH
- Polystyrenes chemistry MeSH
- Surface Properties MeSH
- Swine MeSH
- Cell Proliferation MeSH
- Muscle, Smooth, Vascular cytology MeSH
- Materials Testing MeSH
- Tissue Engineering methods MeSH
- Adipose Tissue metabolism MeSH
- Xanthenes chemistry MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Teriflunomid je léčivý preparát pro léčbu roztroušené sklerózy jako jedna z možností terapie 1. linie. Dle studií na zvířatech má teratogenní a embryotoxický potenciál. Data o užívání v těhotenství u žen jsou omezená a jeho užívání v graviditě je kontraindikováno. Článek se zabývá problematikou gravidity během expozice teriflunomidem.
Teriflunomide is a disease modyfing drug for treatment in multiple sclerosis as one of the options for first-line therapy. It has teratogenic and embyotoxic potential according to animal studies. The data on pregnancy use in women are limited and its use in pregnancy is contraindicated. However, there are cases where women have taken teriflunomide during conception and pregnancy.
- Keywords
- teriflunomid,
- MeSH
- Cholestyramine Resin administration & dosage MeSH
- Cesarean Section MeSH
- Adult MeSH
- Fertility drug effects MeSH
- Contraindications MeSH
- Crotonates blood adverse effects therapeutic use MeSH
- Humans MeSH
- Methylprednisolone administration & dosage MeSH
- Neurologic Manifestations MeSH
- Recurrence MeSH
- Multiple Sclerosis * drug therapy MeSH
- Pregnancy, Twin MeSH
- Pregnancy * drug effects MeSH
- Toluidines blood adverse effects therapeutic use MeSH
- Pregnancy Outcome epidemiology MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Pregnancy * drug effects MeSH
- Female MeSH
- Publication type
- Case Reports MeSH
Introduction of microfluidic mixing technique opens a new door for preparation of the liposomes and lipid-based nanoparticles by on-chip technologies that are applicable in a laboratory and industrial scale. This study demonstrates the role of phospholipid bilayer fragment as the key intermediate in the mechanism of liposome formation by microfluidic mixing in the channel with "herring-bone" geometry used with the instrument NanoAssemblr. The fluidity of the lipid bilayer expressed as fluorescence anisotropy of the probe N,N,N-Trimethyl-4-(6-phenyl-1,3,5-hexatrien-1-yl) was found to be the basic parameter affecting the final size of formed liposomes prepared by microfluidic mixing of an ethanol solution of lipids and water phase. Both saturated and unsaturated lipids together with various content of cholesterol were used for liposome preparation and it was demonstrated, that an increase in fluidity results in a decrease of liposome size as analyzed by DLS. Gadolinium chelating lipids were used to visualize the fine structure of liposomes and bilayer fragments by CryoTEM. Experimental data and theoretical calculations are in good accordance with the theory of lipid disc micelle vesiculation.
- MeSH
- Biocompatible Materials metabolism MeSH
- Cholestyramine Resin metabolism MeSH
- Membrane Fluidity * MeSH
- Fluorescence Polarization MeSH
- Lab-On-A-Chip Devices MeSH
- Liposomes chemical synthesis MeSH
- Microfluidics instrumentation methods MeSH
- Nanostructures * MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
This study presents a proof of principle concept for a two-dimensional bioprinted glucose sensor on Petri dishes that allows for glucose measurements in cell culture medium. To improve bioink adhesion, the polystyrene surfaces of standard Petri dishes are activated with argon plasma, which increases roughness and hydrophilicity. The bioink containing the sensor chemistry - namely fluorescently labeled ConA/Dextran embedded in alginate microbeads - was printed on the activated Petri dishes with an extrusion-based bioprinter. The printed sensor showed good stability and adhesive properties on polystyrene. The glucose concentration was examined using a standard fluorescence microscope with filters adapted to the emission wavelength of the donor and reference dyes. The printed glucose sensor showed high sensitivity and good linearity in a physiologically relevant range of glucose concentrations.
- MeSH
- Printing, Three-Dimensional MeSH
- Biosensing Techniques * methods MeSH
- Glucose analysis MeSH
- Hydrogels chemistry MeSH
- Humans MeSH
- Polystyrenes MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
