Poly(2-alkenyl-2-oxazoline)s are promising functional polymers for a variety of biomedical applications, such as drug delivery systems, peptide conjugates, or gene delivery. In this study, poly(2-isopropenyl-2-oxazoline) (PIPOx) is prepared through free-radical polymerization initiated with azobisisobutyronitrile. Reactive 2-oxazoline units in the side chain support an addition reaction with different compounds containing a carboxylic group, which facilitates the preparation of polymers labeled with two different fluorescent dyes. The cytotoxicities of 2-oxazoline monomers, PIPOx, and fluorescently labeled PIPOx are evaluated in vitro using an 3-(4,5-Dimethyldiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and ex vivo using a cell proliferation assay with adenosine triphosphate bioluminescence. The cell uptake of labeled PIPOx is used to determine the colocalization of PIPOx with cell organelles that are part of the endocytic pathway. For the first time, it is shown that poly(2-isopropenyl-2-oxazoline) is a biocompatible material and is suitable for biomedical applications; further, its immunomodulative properties are evaluated.
- MeSH
- biokompatibilní materiály chemická syntéza chemie farmakologie MeSH
- buněčná smrt účinky léků MeSH
- buňky 3T3 MeSH
- endocytóza účinky léků MeSH
- fibroblasty cytologie MeSH
- fluorescenční spektrometrie MeSH
- imunomodulace účinky léků MeSH
- konfokální mikroskopie MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- organely účinky léků metabolismus MeSH
- oxazoly chemická syntéza chemie farmakologie MeSH
- polymery chemická syntéza chemie farmakologie MeSH
- polypropyleny chemická syntéza chemie farmakologie MeSH
- proliferace buněk účinky léků MeSH
- slezina cytologie MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The influence of acidic (5.6) and neutral (7.0) pH and glucose concentrations (0.9 and 2 %) was determined in in vitro biofilm formation and the cell surface hydrophobicity (CSH) in fluconazole (FLC) susceptible and tolerant yeasts of Candida albicans. The determination of biofilm viability using tetrazolium salt XTT showed that both FLC-tolerant C. albicans 1173 and FLC-sensitive C. albicans SC 5314 formed more robust biofilm in the YNB medium at pH 7.0 in the absence of FLC than that at acidic pH. Tested glucose concentrations did not show any direct effect on formation of biofilm under all conditions. However, determination of biofilm dry mass that contains also extracellular matrix suggested some effect of 2 % D-glucose. An increase in CSH (for about 10 %) was estimated in C. albicans SC 5314 in the presence of FLC, while the FLC-tolerant isolate proved a weak increase of CSH only in the YNB media containing 2 % D-glucose. Additionally, strain C. albicans SC 5314 strongly flocculated at neutral pH in the absence of FLC, but this phenomenon was not observed in the presence of FLC. Subinhibitory concentration of FLC influenced biofilm cells and CSH, but FLC susceptibility versus tolerance of C. albicans tested strains did not directly affect biofilm formation and/or CSH.
- MeSH
- antifungální látky farmakologie MeSH
- biofilmy účinky léků MeSH
- Candida albicans chemie účinky léků růst a vývoj metabolismus MeSH
- flukonazol farmakologie MeSH
- glukosa metabolismus MeSH
- hydrofobní a hydrofilní interakce MeSH
- kultivační média chemie metabolismus MeSH
- mikrobiální testy citlivosti MeSH
- povrchové vlastnosti účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Introduction. Chronic kidney disease (CKD) has been referred to as a state of cellular calcium toxicity. The aim of this study was to investigate the status of free cytosolic calcium ([Ca 2+ ] i ) and intracellular calcium reserves and the capacitative calcium entry in peripheral blood mononuclear cells (PBMCs) of CKD patients, and to determine the effect of vitamin D3 supplementation on these parameters. Methods. The study involved 44 patients with CKD sta- ges 2-3 and 70 healthy volunteers. 27 were treated with cholecalciferol (5000 IU/week) for 12 months. [Ca 2+ ] i was measured using Fluo-3 AM fluorimetry. Intracellular calci- um reserves were emptied by the application of thapsigar- gin (Tg), a specific inhibitor of endoplasmic reticulum Ca 2+ - ATPase. 2-Aminoethyl-diphenyl borate (2APB) was used to examine the capacitative calcium entry. Results. [Ca 2+ ] i of CKD patients was substantially higher in comparison with healthy subjects: 123 (115-127) vs 102 (98-103) nmol/l; p<0.001. The calcium concentration of Tg-sensitive stores and the capacitative calcium entry were also significantly increased in CKD patients. After the 12- month vitamin D3 supplementation, there was a marked decrease in [Ca 2+ ] i [105 (103-112) nmol/l; p<0.001 vs. baseline], independently of the increase in 25(OH)D 3 or the decrease in PTH levels. No significant changes in intracel- lular calcium reserves and the capacitative calcium entry were found. Conclusions. Our results demonstrate that: (1) [Ca 2+ ] i , intracellular calcium stores and the capacitative calcium entry were significantly increased already in early stages of CKD; (2) long-term vitamin D3 supplementation normalized [Ca 2+ ] i without any effect on intracellular calcium reserves or the capacitative calcium entry.
Objective of this study was to characterize osmotically-induced insulin secretion in two tumor cell lines. We compared response of freshly isolated rat pancreatic islets and INS-1 and INS-1E tumor cell lines to high glucose, 30 % hypotonic medium and 20 % hypertonic medium. In Ca2+-containing medium glucose induced insulin release in all three cell types. Hypotonicity induced insulin secretion from islets and INS-1 cells but not from INS-1E cells, in which secretion was inhibited despite similar increase in cell volume in both cell types. GdCl3 (100 μmol/l) did not affect insulin response from INS-1E cells to hypotonic challenge. Hypertonic medium inhibited glucose-induced insulin secretion from islets but not from tumor cells. Noradrenaline (1 μmol/l) inhibited glucose-induced but not swelling-induced insulin secretion from INS-1 cells. Surprisingly, perifusion with Ca2+-depleted medium showed distinct secretory response of INS-1E cells to hypotonicity while that of INS-1 cells was partially inhibited. Functioning glucose-induced insulin secretion is not sufficient prerequisite for hypotonicity-induced response in INS- 1E cells suggesting that swelling-induced exocytosis is not essential step in the mechanism mediating glucose-induced insulin secretion. Both cell lines are resistant to inhibitory effect of hyperosmolarity on glucose-induced insulin secretion. Response of INS-1E cells to hypotonicity is inhibited by the presence of Ca2+ in medium.
- Klíčová slova
- Cell volume, Insulin secretion, Pancreatic islets, Tumor cell line, Ca2+ and exocytosis,
- MeSH
- exocytóza MeSH
- financování organizované MeSH
- gadolinium farmakologie MeSH
- glukosa metabolismus MeSH
- hypertonické roztoky MeSH
- hypotonické roztoky MeSH
- inzulin sekrece MeSH
- inzulinom metabolismus sekrece MeSH
- krysa rodu rattus MeSH
- Langerhansovy ostrůvky metabolismus sekrece účinky léků MeSH
- nádorové buněčné linie MeSH
- nádory slinivky břišní metabolismus sekrece MeSH
- noradrenalin metabolismus MeSH
- osmotický tlak MeSH
- potkani Wistar MeSH
- vápník metabolismus nedostatek MeSH
- velikost buňky MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
