| Abstract [eng] |
Miglė Dainovskytė‘s Master‘s thesis is titled “Study of adapalene encapsulation into liposomes and it’s release.” The supervisor of the research is Rima Budvytytė PhD. Research was carried out at the Department of Bioelectrochemistry and Biospectroscopy at the Institute of Biochemistry in the Life Sciences Center of Vilnius University. Aim of the research: to form and characterize liposomes suitable for drug delivery and to use them for the encapsulation of adapalene for the treatment of acne. Objectives of the research: 1. Evaluate the size and stability of liposomes of different compositions depending on different storage conditions (time, temperature). 2. Determine the release of the fluorescent dye calcein inserted into liposomes. 3. Evaluate the incorporation of adapalene into liposomes by measuring its fluorescence. Object and methods of the research: the object of the Master's thesis was lipid-based nanocarriers - liposomes – with and without the drug substance adapalene. The size and stability of liposomes of different compositions were characterized by the dynamic light scattering method, the stability of liposome membranes was assessed based on changes in the fluorescence intensity of released calcein from liposomes, and the presence of adapalene in liposomes was determined by the fluorescence spectroscopy. Results and conclusions: after examining four different compositions of liposomes (DOPC/Chol (6:4), DOPC/DOPG (7:3), DOPC/Chol/DOPG (5:3.5:1.5), and DOPC/Chol/DSPE-PEG(2000) (5.64:3.83:5.3)) using the dynamic light scattering method at different temperatures, it was determined that all composition liposomes were the most stable at room temperature (22oC) over a week due to the smallest average radius size changes, while the liposomes showed the least stability at 37oC due to the most significant changes in radius size. After measuring the fluorescence of released calcein from different composition liposomes, it was found that the least stable were lipid vesicles composed of DOPC and Chol (6:4) due to the largest fluorescence intensity changes, while the most stable were PEG residue-containing liposomes due to the least change in fluorescence intensity. Evaluating the effect of different temperatures on liposome stability, it is seen that all four composition liposomes were the least stable at a temperature of 37oC, while the temperature of 22oC was the most favorable for the stability of lipid vesicles due to the lowest amount of released calcein. After measuring the fluorescence induced by the release of adapalene from liposomes formed from DOPC / DOPG (7:3) and from PEG residue-containing liposomes, it was found that the highest efficiency of encapsulation of adapalene into lipid vesicles was observed at a temperature of 4oC. Comparing both liposome compositions, the PEG residue-containing liposomes with incorporated adapalene showed greater stability due to higher fluorescence intensity after addition of triton. |
