Permeability coefficient
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Ciel: Zistiť efekt opakovaných intravitreálnych aplikácii afliberceptu na endotel rohovky u pacientov s diabetickým makulárnym edémom (DME) a edémom makuly pri oklúzii retinálnej vény (RVO). Metodika: Do prospektívneho sledovania v období od januára 2021 do novembra 2023 bolo zaradených 87 naivných očí s diagnózou DME a RVO. Exklúzne kritérium pre zaradenie bol operačný alebo laserový zákrok počas sledovacieho obdobia, nosenie kontaktných šošoviek, ope rácia katarakty pred menej ako 6 mesiacmi, dystrofie alebo iné ochorenia rohovky, ktoré môžu spôsobiť zmeny endotelu. Okrem rutinných vyšetrení sme v deň 1., 4. a 8. injekcie vyšetrovali aj endotel rohovky pomocou bezkontaktnej endotelovej mikroskopie. Vyhodnocovali sme 4 parametre: hustotu endotelových buniek (CD), hexagonalitu (HEX), koeficient variability (CV) a centrálnu hrúbku rohovky (CCT). Najskôr sme vyhodnocovali celý súbor očí a následne sme ho rozdelili podľa 2 kritérií; podľa diagnózy na DME/RVO a podľa šošovky na fakické/pseu dofakické oči. Výsledky: Vyhodnotených bolo 87 očí (68 pacientov). Priemerný vek pacientov v čase diagnózy bol 66,8 ±9,3 rokov. Z celkového počtu 87 bolo 51 (59 %) fakických a 36 (41 %) pseudofakických očí. S diagnózou DME bolo liečených 61 (70 %) očí a s diagnózou RVO 26 (30 %). V prie behu sledovania nedošlo vplyvom liečby k štatisticky signifikantnej zmene priemerných hodnôt CD, HEX, CV, CCT či už v súbore všetkých očí alebo v rozdelení do podskupín podľa diagnózy či stavu šošovky. Záver: Zistili sme, že intravitreálne aplikácie afliberceptu u pacientov s DME a RVO neovplyvňujú parametre rohovkového endotelu ako CCT, HEX, CD, CV hodnotené pomocou endotelovej mikroskopie pri sledovaní po 8 injekciu.
Aim: To determine the effect of repeated intravitreal injections of aflibercept on the corneal endothelium in patients with diabetic macular edema (DME) and macular edema due to retinal vein occlusion (RVO). Methods: In a prospective study conducted between January 2021 and November 2023, a total of 87 treatment-naive eyes with DME and RVO were evaluated. The exclusion criteria were surgery or laser intervention during the follow-up period, contact lens wear, cataract surgery in the last 6 months, dystrophy, or other corneal condition that may cause endothelial damage. In addition to routine examinations on the day of application, we also measured the corneal endothelium using specular microscopy on the 1st, 4th and 8th day of injection. We evaluated 4 parameters: endothelial cell density (CD), hexagonality (HEX), coefficient of variability (CV) and central corneal thickness (CCT). First of all, we evaluated the entire cohort of eyes, and then divided it according to 2 criteria; the diagnosis into DME/RVO and according to the lens status into phakic/pseudophakic eyes. Results: A total of 87 eyes of 68 patients were evaluated. The average age of the patients at the time of diagnosis was 66.8 ±9.3 years. Within the cohort 51 (59%) eyes were phakic and 36 (41%) pseudophakic. A total of 61 (70%) eyes with a diagnosis of DME were treated, and 26 (30%) with RVO. During the follow-up, there were no significant changes in the average values of CD, HEX, CV, CCT due to aflibercept treatment, either in the whole group or in subgroups according to diagnosis or lens condition. Conclusions: The results of this study suggest that intravitreal administration of aflibercept in patients with DME and RVO did not have an impact on corneal endothelial parameters, including CCT, HEX, CD and CV. These parameters were measured using endothelial microscopy during an 8-injection observation period.
- Klíčová slova
- aflibercept,
- MeSH
- bevacizumab aplikace a dávkování farmakologie terapeutické užití MeSH
- endoteliální buňky účinky léků MeSH
- humanizované monoklonální protilátky farmakologie klasifikace terapeutické užití MeSH
- inhibitory angiogeneze * aplikace a dávkování farmakologie klasifikace terapeutické užití MeSH
- injekce intravitreální * klasifikace metody MeSH
- lidé MeSH
- makulární edém chemicky indukované etiologie MeSH
- mikroskopie klasifikace metody MeSH
- počet buněk MeSH
- prospektivní studie MeSH
- rohovkový endotel diagnostické zobrazování účinky léků MeSH
- vaskulární endoteliální růstový faktor A antagonisté a inhibitory MeSH
- Check Tag
- lidé MeSH
Cryopreservation of spheroids requires development of new improved methods. The plasma membranes permeability coefficients for water and cryoprotectants determine time characteristics of mass transfer through the cell membranes, and therefore the optimal modes of cells cryopreservation. Here we proposed an approach to cryopreservation of multicellular spheroids which considers their generalized characteristics as analogues of the membranes' permeability coefficients of the individual cells. We have determined such integral characteristics of spheroids from mesenchymal stromal cells (MSCs) as osmotically inactive volume; permeability coefficients for water and Me2SO molecules and the activation energy of their penetration. Based on these characteristics, we calculated the osmotic behavior of multicellular spheroids under cooling conditions to select the optimal cooling rate. We also determined the optimal cooling rate of spheroids using the probabilistic model developed based on the two-factor theory of cryodamage. From the calculation it follows that the optimal cooling rate of the MSC-based spheroids is 0.75°С/min. To verify the obtained theoretical estimates, we conducted experiments on freezing MSC-based spheroids under different modes. The obtained results of primary viability screening indicate that freezing at a constant linear cooling rate of 0.75-1.0°С/min gives a good result. Theoretical prediction of the spheroid osmotic behavior during cooling provided the basis for experimental verification of varying the temperature to which slow cooling should be carried out before immersion in liquid nitrogen. Slow freezing of spheroids to -40 °C followed by immersion in liquid nitrogen was shown to preserve cells better than slow freezing to -80 °C. Obtained data allow more effective use of MSC-based spheroids in drug screening and regenerative medicine.
- MeSH
- buněčné sféroidy * cytologie MeSH
- kryoprezervace * metody MeSH
- kryoprotektivní látky * farmakologie MeSH
- kultivované buňky MeSH
- lidé MeSH
- mezenchymální kmenové buňky * cytologie MeSH
- permeabilita buněčné membrány MeSH
- viabilita buněk * MeSH
- voda chemie MeSH
- zmrazování MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Based on the mimicry of microbial metabolites, functionalized indoles were demonstrated as the ligands and agonists of the pregnane X receptor (PXR). The lead indole, FKK6, displayed PXR-dependent protective effects in DSS-induced colitis in mice and in vitro cytokine-treated intestinal organoid cultures. Here, we report on the initial in vitro pharmacological profiling of FKK6. FKK6-PXR interactions were characterized by hydrogen-deuterium exchange mass spectrometry. Screening FKK6 against potential cellular off-targets (G protein-coupled receptors, steroid and nuclear receptors, ion channels, and xenobiotic membrane transporters) revealed high PXR selectivity. FKK6 has poor aqueous solubility but was highly soluble in simulated gastric and intestinal fluids. A large fraction of FKK6 was bound to plasma proteins and chemically stable in plasma. The partition coefficient of FKK6 was 2.70, and FKK6 moderately partitioned into red blood cells. In Caco2 cells, FKK6 displayed high permeability (A-B: 22.8 × 10-6 cm.s-1) and no active efflux. These data are indicative of essentially complete in vivo absorption of FKK6. The data from human liver microsomes indicated that FKK6 is rapidly metabolized by cytochromes P450 (t1/2 5 min), notably by CYP3A4. Two oxidized FKK6 derivatives, including DC73 (N6-oxide) and DC97 (C19-phenol), were detected, and these metabolites had 5-7 × lower potency as PXR agonists than FKK6. This implies that despite high intestinal absorption, FKK6 is rapidly eliminated by the liver, and its PXR effects are predicted to be predominantly in the intestines. In conclusion, the PXR ligand and agonist FKK6 has a suitable pharmacological profile supporting its potential preclinical development.
Encapsulation into liposomes is a formulation strategy that can improve efficacy and reduce side effects of active pharmaceutical ingredients (APIs) that exhibit poor biodistribution or pharmacokinetics when administered alone. However, many APIs are unsuitable for liposomal formulations intended for parenteral administration due to their inherent physicochemical properties─lipid bilayer permeability and water-lipid equilibrium partitioning coefficient. Too high permeability results in premature leakage from liposomes, while too low permeability means the API is not able to pass across biological barriers. There are several options for solving this issue: (i) change of the lipid bilayer composition, (ii) addition of a permeability enhancer, or (iii) modification of the chemical structure of the API to design a prodrug. The latter approach was taken in the present work, and the effect of small changes in the molecular structure of the API on its permeation rate across a lipidic bilayer was systematically explored utilizing computer simulations. An in silico methodology for prodrug design based on the COSMOperm approach has been proposed and applied to four APIs (abiraterone, cytarabine, 5-fluorouracil, and paliperidone). It is shown that the addition of aliphatic hydrocarbon chains via ester or amide bonds can render the molecule more lipophilic and increase its permeability by approximately 1 order of magnitude for each 2 carbon atoms added, while the formation of fructose adducts can provide a more hydrophilic character to the molecule and reduce its lipid partitioning. While partitioning was found to depend only on the size and type of the added group, permeability was found to depend also on the added group location. Overall, it has been shown that both permeability and lipid partitioning coefficient can be systematically shifted into the desired liposome formulability window by appropriate group contributions to the parental drug. This can significantly increase the portfolio of APIs for which liposome or lipid nanoparticle formulations become feasible.
PURPOSE: The aim of this study was to investigate whether there is any association between the levels of the angiogenic growth factors and the vascular oxygen saturation in eyes with diabetic retinopathy. METHODS: The study was designed as a prospective trial. The cohort consisted of 29 diabetic patients with scheduled vitreous procedures (intravitreal injection or pars plana vitrectomy). The control group included 30 patients scheduled for macular surgery (macular hole or epiretinal membrane). Nine patients (four from the diabetic maculopathy [DM] group and five from the control group) were excluded from the study because of unsuccessful vitreous samples. Retinal oximetry was performed several hours before the vitreous procedure was performed, and vitreous samples were obtained during the procedure. The concentrations of VEGF, Serpin F1/pigment epithelium-derived factor (PEDF), and placental growth factor (PlGF) were measured by ELISA. RESULTS: A negative correlation between level of VEGF and arteriovenous (AV) saturation difference was determined in the DM group (Pearson correlation coefficient r = -0.607; two-tailed test, P = 0.002). Also a negative correlation between level of PlGF and AV saturation difference was determined in the DM group (Pearson correlation coefficient r = -0.521; two-tailed test, P = 0.011) A positive correlation between PlGF level and the vein saturation was not statistically significant (Pearson correlation coefficient r = 0.325; two-tailed test, P = 0.130). We did not find any correlation between vitreous level of PEDF and vascular saturation within the DM group. CONCLUSIONS: Our findings in diabetic patients suggests a correlation between the intravitreal level of proangiogenic factors and the AV difference measured by retinal oximetry.
- MeSH
- diabetes mellitus * MeSH
- diabetická retinopatie * MeSH
- lidé MeSH
- placentární růstový faktor MeSH
- prospektivní studie MeSH
- retina MeSH
- retinální cévy MeSH
- saturace kyslíkem MeSH
- vaskulární endoteliální růstový faktor A MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
This article presents the possibility of using diffusion dialysis for processing spent pickling solution from pickling stainless steels with a mixture of nitric acid and hydrofluoric acid. A counter-current two-compartment dialyzer equipped with an anion-exchange membrane Neosepta-AFN was used to study and compare the diffusion dialysis of model mixture of hydrofluoric acid and ferric nitrate and a real spent pickling solution. The separation efficiency was characterized by the acid recovery yield, the rejection coefficient of the metals, the permeability coefficient of the membrane, and the separation factor. These characteristics were calculated from the data obtained at steady state. For the real spent pickling solution tested, the permeability values of nitrates 1.7 × 10-6 m s-1, fluorides 0.4 × 10-6 m s-1, and ferric ions 1.1 × 10-7 m s-1 were achieved. The separation factor for nitrates/ferric ions was 15.7 and 3.6 for fluorides/ferric ions. Furthermore, the dependencies of recovery yield and rejection for different concentrations of hydrofluoric acid and ferric nitrate were determined.
- Publikační typ
- časopisecké články MeSH
Propofol has been shown to against intestinal reperfusion injury when treated either before or after ischemia, during which mast cell could be activated. The aim of this study was to evaluate the role of propofol in restoring the intestinal epithelial cells integrity disrupted by mast cell activation or the released tryptase after activation in vitro. We investigated the effect of: (1) tryptase on Caco-2 monolayers in the presence of PAR-2 inhibitor or propofol, (2) mast cell degranulation in a Caco-2/LAD-2 co-culture model in the presence of propofol, and (3) propofol on mast cell degranulation. Epithelial integrity was detected using transepithelial resistance (TER) and permeability to fluorescein isothiocyanate (FITC)-dextran (the apparent permeability coefficient, Papp). The expression of junctional proteins zonula occludens-1 (ZO-1/TJP1) and occludin were determined using western blot analysis and immunofluorescence microscopy. The intracellular levels of reactive oxidative species (ROS) and Ca2+ were measured using flow cytometry. Tryptase directly enhanced intestinal barrier permeability as demonstrated by significant reductions in TER, ZO-1, and occludin protein expression and concomitant increases in Papp. The intestinal barrier integrity was restored by PAR-2 inhibitor but not by propofol. Meanwhile, mast cell degranulation resulted in epithelial integrity disruption in the Caco-2/LAD-2 co-culture model, which was dramatically attenuated by propofol. Mast cell degranulation caused significant increases in intracellular ROS and Ca(2+) levels, which were blocked by propofol and NAC. Propofol pretreatment can inhibit mast cell activation via ROS/Ca(2+) and restore the intestinal barrier integrity induced by mast cell activation, instead of by tryptase.
- MeSH
- Caco-2 buňky MeSH
- degranulace buněk MeSH
- epitelové buňky metabolismus MeSH
- lidé MeSH
- mastocyty metabolismus MeSH
- okludin metabolismus MeSH
- permeabilita MeSH
- propofol * farmakologie MeSH
- reaktivní formy kyslíku metabolismus MeSH
- střevní sliznice metabolismus MeSH
- tryptasy metabolismus farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Drug compounds including memantine moieties are an important group of biologically active agents for different pathologies, including the Alzheimer's disease. In the present study, a series of memantine derivatives incorporating amino acid residues have been synthesized and their neuroprotective in vitro evaluation in respect of the Alzheimer's disease, involving the effects on the resistance to Aβ toxicity, excitotoxicity, oxidative stress, hypoxia, and neuroinflammation has been studied. The cytotoxicities of the compounds were detected by CPE assay. TC50 and IC50 were determined using Reed and Muench method. Solubility and distribution were measured using a shake-flask method. Permeability of the compounds was studied using Franz diffusion cell and Permeapad™ barrier. These compounds displayed apparent multi-neuroprotective effects against copper-triggered Aβ toxicity, glutamate-induced excitotoxicity, and oxidative and hypoxic injuries. They also showed the ability to inhibit the inflammatory cytokine release from the activated microglia and potential anti-neuroinflammatory effects. Especially, two most promising compounds H-4-F-Phe-memantine and H-Tyr-memantine demonstrated the equivalent functional bioactivities in comparison with the positive control memantine hydrochloride. Higher solubility in muriatic buffer than in phosphate buffer was detected. The distribution coefficients showed the optimal lipophilicity for compounds. The presented results propose new class of memantine derivatives as potential drug compounds. Based on the experimental results, the correlations have been obtained between the biological, physicochemical parameters and structural descriptors. The correlation equations have been proposed to predict the properties of new memantine derivatives knowing only the structural formula.
- MeSH
- Alzheimerova nemoc farmakoterapie genetika patologie MeSH
- amyloidní beta-protein účinky léků toxicita MeSH
- buňky MDCK MeSH
- chřipka lidská farmakoterapie virologie MeSH
- kyselina glutamová metabolismus MeSH
- lidé MeSH
- memantin analogy a deriváty chemie farmakologie MeSH
- neuroprotektivní látky chemie farmakologie MeSH
- Orthomyxoviridae účinky léků patogenita MeSH
- oxidační stres účinky léků MeSH
- psi MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Profiling blood-brain barrier permeability of bioactive molecule is an important issue in early drug development, being a part of the optimization process of a compound's physicochemical properties, and hence pharmacokinetic profile. The study aimed to develop and optimize a new in vitro method for assessment of the compound's brain penetration. The tool is proposed as an alternative to the PAMPA-BBB (Parallel Artificial Membrane Permeability Assay for Blood-Brain Barrier) and based on a capillary electrochromatography (CEC) technique. It utilizes liposomes as structural substitutes of biological membranes, which are used as a capillary inner wall coating material. Following optimization of analysis conditions, migration times for a set of 25 reference drugs (mainly non-ionized in pH 7.4) were examined in a liposome coated capillary. On that basis, the retention factor (log k) was determined for each reference drug. Obtained log k values and experimentally received reference permeability parameters: log BB (in vivo data) and log Pe (PAMPA-BBB data) were compared with one another. Correlation coefficients were calculated, giving comparable results for CEC log k/log BB and analogical PAMPA-BBB log Pe/log BB analyses. Approximate ranges of log k for the central nervous system (CNS) permeable (CNS(+)) and non-permeable (CNS(-)) drugs were established.
- MeSH
- elektroforéza kapilární MeSH
- hematoencefalická bariéra chemie MeSH
- léčivé přípravky analýza MeSH
- lidé MeSH
- liposomy chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The purpose of calculating the capillary filtration coefficient is to experimentally evaluate edema formation in models of pulmonary ischemia-reperfusion injury. For many years, the obtaining of this coefficient implies a series of manual maneuvers during ex-vivo reperfusion of pulmonary arterial pressure, venous pressure and weight, as well as the calculation of the Kfc formula. Through automation, the calculation of capillary filtration coefficient could be easier and more efficient. To describe an automatic method designed in our laboratory to calculating the capillary filtration coefficient and compare with traditional determination of capillary filtration coefficient as gold standard method. An automatic three valve perfusion system was constructed, commanded by a mastery module connected to a graphical user interface. To test its accuracy, cardiopulmonary blocks of Wistar rats were harvested and distributed in manual (n=8) and automated (n=8) capillary filtration coefficient determination groups. Physiological parameters as pulmonary arterial pressure, pulmonary venous pressure, weight and capillary filtration coefficient were obtained. Results: Capillary filtration coefficient, pulmonary arterial pressure, venous arterial pressure shown no statistical significance difference between the groups. The automated perfusion system for obtaining Kfc was standardized and validated, giving reliable results without biases and making the process more efficient in terms of time and personal staff.
- MeSH
- arteria pulmonalis fyziologie MeSH
- kapilární permeabilita fyziologie MeSH
- kapiláry fyziologie MeSH
- krysa rodu rattus MeSH
- orgánové kultury - kultivační techniky MeSH
- perfuze přístrojové vybavení metody MeSH
- plicní tlak v zaklínění fyziologie MeSH
- potkani Wistar MeSH
- venae pulmonales fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
