magistrsko delo
Urška Zagorc (Avtor), Ksenija Kogej (Mentor), Aljaž Gaber (Član komisije za zagovor), Veronika Kralj-Iglič (Član komisije za zagovor)

Povzetek

V organizmih ves čas poteka medcelična komunikacija pri kateri sodelujejo zunajcelični vezikli. Preko veziklov se prenašajo nukleinske kisline, proteini in različni metaboliti. Interakcije veziklov s tarčnimi celicami imajo različne posledice, kot sta na primer zaviranje tumorske aktivnosti in stimulacija signalnih poti. Umetne vezikle lahko enostavno pripravimo, hkrati pa njihove lastnosti omogočajo raznoliko uporabo. Med drugim jih uporabljamo kot sistem za dostavo zdravil in cepiv ter za prognostiko in diagnostiko številnih bolezni. V magistrskem delu smo s pomočjo ekstruzije pripravili umetne vezikle iz 1-palmitoil-2-oleoil-sn-glicero-3-fosfoholin lipida (POPC), ki smo jim dodajali po naboju različne surfaktante in polielektrolite za proučitev vpliva teh spojin na njihovo stabilnost. Spremljali smo vpliv surfaktantov in polielektrolitov na velikost in obliko veziklov, ter njihovo stabilnost pri različnih temperaturah. Velikost veziklov, intenziteto sipanja svetlobe in njihovo temperaturno stabilnost smo zasledovali z metodo dinamičnega sipanja svetlobe. Ko smo raztopini POPC veziklov dodali kationski surfaktant N-cetilpiridinijev klorid (CPC), anionski surfaktant natrijevega dodecil sulfata (SDS), ali neionski surfaktant Triton X-100 vse do kritične micelne koncentracije (cmc) surfaktanta, ni prišlo do velikih sprememb v velikosti hidrodinamskega radija (Rh) in intenziteti sipane svetlobe. Po preseženi cmc pa je v primeru dodatkov vseh surfaktantov intenziteta močno padla, porazdelitev delcev v suspenzijah pa je postala vedno bolj polidisperzna. Ob dodatkih polielektrolitov ni prišlo do večjih sprememb v velikosti Rh in intenziteti sipanja. Vezikli POPC so bili kljub dodatkom temperaturno izjemno stabilni. Z naraščanjem temperature je prišlo le do razširitve v razporeditvi Rh. S kalorimetrijo smo spremljali toplotne efekte vezave surfaktantov in polielektrolitov na vezikle POPC. Pri vezavah vseh treh surfaktantov na POPC so toplotni efekti eksotermni, pri vezavah polielektrolitov pa so toplotni efekti zanemarljivo majhni. Vezikle smo naredili še na enostavnejši način, to je z enostavnim mešanjem komercialnih lipidov (sojinega in jajčnega lecitina), ter preučevali, kako različne snovi vplivajo na spontano tvorbo hibridnih veziklov ali hibridosomov in njihovo stabilnost. Pri enostavnejšem načinu priprave veziklov ekstruzije nismo uporabili. Hibridosomi so nastali tako v odsotnosti kot tudi v prisotnosti glicerola. Glede na rezultate sklepamo, da glicerol prispeva k izoblikovanju veziklov in bolj homogenim lipidnim strukturam. Zanimalo nas je, kako vplivamo na tvorbo hibridosomov, če mešanici namesto vode dodamo ekstrakt iz smrekovih iglic, ki vsebujejo številne zdravilne učinkovine. Hibridosomi so nastali tudi v tem primeru, do razlik je prišlo le v intenziteti sipanja in velikosti hidrodinamskega radija.

Ključne besede

vezikli;liposomi;priprava umetnih veziklov;hibridosomi;stabilnost;dinamično sipanje svetlobe;magistrska dela;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.09 - Magistrsko delo
Organizacija: UL FKKT - Fakulteta za kemijo in kemijsko tehnologijo
Založnik: [U. Zagorc]
UDK: 576:544.77.022.533(043.2)
COBISS: 169799427 Povezava se bo odprla v novem oknu
Št. ogledov: 44
Št. prenosov: 4
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Effect of surfactants and polyelectrolytes on artificial vesicles and spontaneous vesicle formation
Sekundarni povzetek: In organisms, intercellular communication takes place all the time via extracellular vesicles. Nucleic acids, proteins and various metabolites are transported via vesicles. Interactions of vesicles with target cells have various consequences, such as inhibition of tumour activity and stimulation of signalling pathways. Artificial vesicles can be easily prepared and their properties allow for a wide range of applications. They are used, among other things, as a delivery system for medicines and vaccines, and for the prognosis and diagnosis of many diseases. In the master thesis, artificial vesicles were prepared from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine lipid (POPC) by extrusion, to which different surfactants and polyelectrolytes were added according to their charge in order to study the effect of these compounds on their stability. The influence of surfactants and polyelectrolytes on the size and shape of vesicles and their stability at different temperatures was monitored. The size of the vesicles, the light scattering (LS) intensity of vesicle suspensions and their temperature stability were determined using the dynamic light scattering method. When the cationic surfactant N-cetylpyridinium chloride (CPC), the anionic surfactant sodium dodecyl sulfate (SDS), or the nonionic surfactant Triton X-100 were added to the solution of POPC vesicles up to the critical micelle concentration (cmc) of the surfactant, there were no large changes in the size of the hydrodynamic radius (Rh) and intensities. After the cmc was exceeded, however, in the case of additions of all surfactants, the intensity dropped sharply, the samples became more and more polydisperse. With the addition of polyelectrolytes, there were no major changes in Rh size and intensity. Despite the additions, the POPC vesicles were extremely stable with respect to temperature increase. The thermal effects of surfactants and polyelectrolytes binding to POPC vesicles were monitored by calorimetry. In case of binding all three surfactants to POPC, the thermal effects were exothermic, while when binding polyelectrolytes, the thermal effects were negligible. We prepared the vesicles in an even simpler way, by simply mixing commercial lipids (soy and egg lecithin), and studied how different substances affect the spontaneous formation of hybrid vesicles or hybridosomes and their stability. In this simpler method of preparing vesicles, we did not use extrusion. Hybridosomes were formed both in the absence and presence of glycerol. Based on the results, we conclude that glycerol contributes to the formation of vesicles and more homogeneous lipid structures. We were interested in how we influence the formation of hybridosomes if, instead of water, an extract from spruce needles, which contain many active ingredients, is added to the mixture. Hybridosomes were formed also in this case, the differences were only in the scattering intensity and the size of the hydrodynamic radius.
Sekundarne ključne besede: vesicles;surfactant;polyelectrolyte;dynamic light scattering;hybridosomes;stability;Površinsko aktivne snovi;Polielektroliti;Univerzitetna in visokošolska dela;
Vrsta dela (COBISS): Magistrsko delo/naloga
Študijski program: 1000377
Konec prepovedi (OpenAIRE): 1970-01-01
Komentar na gradivo: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Biokemija
Strani: 75 str.
ID: 19909015