Összes szerző

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Czirók András

az alábbi absztraktok szerzői között szerepel:

Czirók András
Transport kinetics of a small apolar drug candidate passing through a transwell barrier model – mathematical analysis and automated sampling

Aug 30 - szerda

15:12 – 15:30

Sejtanalitika biofizikai megközelítéssel

E36

Transport kinetics of a small apolar drug candidate passing through a transwell barrier model -- mathematical analysis and automated sampling

Júlia Tárnoki-Zách¹, Kata Horváti², Bernadett Pályi³, Zoltán Kis³, Szilvia Bősze^4,3, András Czirók¹

1 Department of Biological Physics, Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117, Budapest, Hungary

2 MTA-TTK Lendület Peptide-Based Vaccines Research Group, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest H-1117, Hungary.

3 National Public Health Center, Albert Flórián út 2-6, Budapest, 1097, Hungary

4 ELKH-ELTE Research Group of Peptide Chemistry, Eötvös Loránd Research Network, Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117, Budapest, Hungary

In the preclinical phase of drug development, it is necessary to determine how the pharmacological compound can pass through the biological barriers surrounding the target tissue. In vitro barrier models provide a reliable, low-cost, high-throughput solution for screening substances at an early stage of the drug development process, thus reducing more complex and costly animal studies.

The transport properties of an in vitro 3D barrier model were determined using a drug candidate. The drug was delivered into the apical chamber of the transwell device, and the concentration of the drug passing through the barrier layer was determined by automated liquid sampling and subsequent spectroscopic analysis. The measurement system replaces the media in the basolateral compartment every 30 minutes for 6 hours and stores the collected samples for further analysis. During the experiment more than half of the compound loaded into the apical compartment passes through the barrier into the basolateral compartment, binds to the filter membrane, accumulates in the cells, or gets metabolized.

Comparison of the time-dependent concentration profiles obtained from both the cellular barrier and membranes saturated with serum proteins reveals the extent the cell layer functions as a diffusion barrier to the compound. Due to the large number of collected samples a detailed mathematical model of the diffusive currents can be fitted to the measured concentration profiles. Based on the fitted parameters, one can determine the diffusivity of the drug in the cell layer, the affinity of the drug binding to the cell membrane as well as the rate by which the cells metabolize the compound. This novel sampling and quantitative analysis approach goes beyond the standard permeability coefficient obtained from transwell inserts and thus offers more detailed pharmacokinetic characterization of the transwell barrier model.

Tárnoki-Zách Júlia
Evaluation of peptide carrier candidates using tissue barrier models

Aug 30 - szerda

15:30 – 17:00

II. Poszterszekció

P56

Evaluation of peptide carrier candidates using tissue barrier models

Júlia Tárnoki-Zách¹, Bence Stipsicz^2,3, Előd Méhes¹, Ildikó Szabó^2,4, Kata Horváti⁴, Bernadett Pályi⁵, Zoltán Kis⁵, Szilvia Bősze^3,5 András Czirók¹

1 Department of Biological Physics, Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117, Budapest, Hungary

2 ELKH-ELTE Research Group of Peptide Chemistry, Eötvös Loránd Research Network, Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117, Budapest, Hungary

3 Doctoral School of Biology, Eötvös Loránd University, Pázmány Péter

sétány 1/C, H-1117, Budapest, Hungary

4 MTA-TTK Lendület Peptide-Based Vaccines Research Group, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest H-1117, Hungary.

5 National Public Health Center, Albert Flórián út 2-6, Budapest, 1097, Hungary

Targeting peptides represent a promising approach to improve uptake and efficiency of pharmacological compounds. In vitro barrier models are valuable screening tools to evaluate peptide transport, uptake and toxicity. Here we characterize a number of readily available lung and kidney epithelial cell lines in a transwell barrier model. After forming a monolayer and a subsequent maturation phase of cell-type specific duration, the epithelial cells develop tight junctions on the surface of polycarbonate inserts as evidenced by beta-catenin and ZO1 immunolabeling as well as delayed transport of targeting peptides. Daily monitoring of transepithelial electrical resistance (TEER) values reveal a cell line specific, characteristic time course. Thus, the TEER method with this calibration data offers a non-destructive and agent-free procedure to time pharmacological transport measurements, and to evaluate cytotoxicity of the transported agents. To characterize peptide targeting efficiency, a detector cell layer was cultured in the basolateral compartment of the barrier tissue model. Uptake of fluorescein-labelled peptides was evaluated by flow cytometry. We demonstrate that a derivative of the well-known peptide penetratin that also contains the neuropilin-binding sequence from tuftsin, a naturally occurring tetrapeptide produced by enzymatic cleavage from immunoglobulin G, is better able to pass through barrier layers that expresses its receptor, NRP-1.