Glycosylated liposomes as a model for the study of molecular recognition and targeted delivery of biologically active compounds

Istraživanja u okviru disertacije bila su usmjerena na pripravu manoziliranih liposoma za ciljanu, receptorima posredovanu dostavu antigena i adjuvanata. Ispitana su dva načina manozilacije liposoma, kovalentno vezanje p-aminofenil-α-D-manopiranozida na prethodno pripravljene liposome i ugrađivanje manoziliranih lipofilnih derivata u lipidni dvosloj liposoma. Korištena su tri strukturno različita lipofilna ostatka, adamantan, palmitinska kiselina i distearoil-fosfatidiletanolamin na koje je različitim poveznicama vezana molekula manoze. Pokazano je da se molekula adamantana može uspješno koristiti kao sidro u lipidnom dvosloju liposoma dok je glikopeptidni dio molekule izložen na površini liposoma. U disertaciji je opisan dizajn i kemijska sinteza mono-, di- i tetravalentnih manoziliranih lipidnih konjugata. Ispitivanje specifičnih interakcija s ConA, spektrofotometrijski i QCM metodom, pokazalo je da afinitet ConA raste s povećanjem broja molekula manoze u glikolipidnim konjugatima. Evaluacija adjuvantske aktivnosti manoziliranih liposomskih formulacija antigena i PGM ili Ad2 TP2 in vivo pokazala je imunomodulacijski učinak.Investigations in the framework of the thesis were focused on the preparation of mannosylated liposomes for targeted, receptors mediated, delivery of antigens and adjuvants. The liposomes were mannosylated in two ways, covalent attachment of p-aminophenyl-α-D-mannopyranoside to preformed liposomes and incorporation of mannosylated lipophilic derivatives into the lipid bilayer of liposomes. Three structurally distinct lipophilic residues were used: adamantane, palmitic acid and distearoylphosphatidylethanolamine in which the molecule of mannose was connected with different linker. It was shown that the adamantane molecule can be successfully used as an anchor in the lipid bilayer of the liposomes while the hydrophilic part of the molecule is exposed on the surface of liposomes. The thesis describes the design and chemical synthesis of mono-, di- and tetravalent mannosylated lipid conjugates. Testing of the specific interactions with ConA, spectrophotometrically and by QCM method, was shown that ConA affinity increases with the increase of the number of molecules of mannose in glycolipid conjugates. Evaluation of adjuvant activity of glycosylated liposomes with built-in antigen and PGM or Ad2TP2, in vivo, has shown immunomodulatory effect