Original title: Příprava a charakterizace teplotně citlivých liposomů
Translated title: Preparation and characterization of temperature sensitive liposomes
Authors: Struhár, Richard ; Málková, Ivana (referee) ; Mravec, Filip (advisor)
Document type: Bachelor's theses
Year: 2025
Language: slo
Publisher: Vysoké učení technické v Brně. Fakulta chemická
Abstract: [slo] [eng]
Teplotne citlivé lipozómy (TSL) predstavujú atraktívnu platformu pre lokálne podávanie biologicky aktívnych látok s riadeným uvoľňovaním, kedy pri miernom zvýšení teploty prechádza ich lipidová dvojvrstva fázovým prechodom a stáva sa tak priepustnejšou pre enkapsulovaný obsah. Práca je zameraná na prípravu, charakterizáciu a funkčné testovanie TSL založených na fosfolipide dipalmitoylfosfatidylcholín (DPPC) s prídavkom rôznych koncentrácií lyzolipidu monopalmitoylfosfatidylcholín (MPPC). Boli zvolené zloženia s obsahom dilauroylglycerofosfátu sodného (PA) aj bez. V prvej fáze boli pripravené vezikuly metódou hydratácie tenkého lipidového filmu (pre rôzne zloženia DPPC:PA:MPPC) v celkovej koncentrácii 5 mmol/dm3 lipidov. Následne boli unilamelarizované 15-násobnou extrúziou cez 100nm membránu. Veľkosť a PDI (index polydisperzity) sa stanovili metódou DLS (dynamický rozptyl svetla), zeta potenciál metódou ELS (elektroforetický rozptyl svetla). Fázové prechody membrán boli sledované fluorescenčnou spektrometriou, ktorou bola zmeraná anizotropia dvoma sondami DPH (difenylhexatrién) a derivátom TMA-DPH (trimetylamónium difenylhexatrién) pri teplotách 10 až 70 °C. Na najperspektívnejšom zložení 90:10 mol. % (DPPC:Lyso PC) bola testovaná kinetika enkapsulovaného hydrofilného kalceínu. Vzorky s 10 mol. % Lyso-PC a 90 mol. % DPPC boli monodisperzné, Z-average 125 nm, PDI Temperature-sensitive liposomes (TSLs) represent an attractive platform for the delivery of controlled-release biologically active agents, whereby upon a slight increase in temperature, their lipid bilayer undergoes a phase transition and thus becomes more permeable to the encapsulated content. This work focuses on the preparation, characterization, and functional testing of TSLs based on phospholipid dipalmitoylphosphatidylcholine (DPPC) with the addition of different lysolipid monopalmitoylphosphatidylcholine (MPPC) concentrations. Compositions both with and without sodium dilauroylglycerophosphate (PA) were chosen. In the first stage, vesicles were prepared by the thin lipid film hydration method (for different compositions of DPPC:PA:MPPC) at a total lipid concentration of 5 mmol/dm3. Subsequently, they were unilamellarized by 15-fold extrusion through a 100 nm membrane. Size and PDI (polydispersity index) were determined by DLS (dynamic light scattering), zeta potential by ELS (electrophoretic light scattering). The phase transitions of the membranes were monitored by fluorescence spectrometry, which measured anisotropy with two probes DPH (diphenylhexatriene) and its derivative TMA-DPH (trimethylammonium diphenylhexatriene) at temperatures between 10 and 70 °C. The kinetics of the encapsulated hydrophilic calcein was tested on the most promising 90:10 mol. % composition (DPPC:Lyso PC). Samples with 10 mol. % Lyso-PC and 90 mol. % DPPC were monodisperse, Z-average was around 125 nm, PDI
Keywords: DPPC; dynamic light scattering (DLS); fluorescence anisotropy; lysolipid; membrane fluidity; membrane phase transition; release kinetics; temperature-sensitive liposomes

Institution: Brno University of Technology (web)
Document availability information: Fulltext is available in the Brno University of Technology Digital Library.
Original record: http://hdl.handle.net/11012/252195

Permalink: http://www.nusl.cz/ntk/nusl-682704


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Universities and colleges > Public universities > Brno University of Technology
Academic theses (ETDs) > Bachelor's theses