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.
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