Design, synthesis and preliminary bio-evaluation of glucose–cholesterol derivatives as ligands for brain targeting liposomes
摘要:
A series of glucose cholesterol derivatives 8a-8e as ligands for brain targeting liposomes were synthesized. The preparation of compound 6 involved temporary protection of glucose with chlorotrimethylsilicane and hexamethyldisilazane followed by selectively hydrolyzed. The known cholesteryl tosylate 1 were coupled to ethylene glycols to afford alcohol 2a-2e. Substitution and deprotection of alcohol 2a-2e furnished the acids 4a-4e, which was condensed with compound 6 to get compounds 7a-7e, and then was deprotected in tetrahydrofuran with TFA to obtain the title compounds. As a model drug, tegafur was entrapped by liposomes coupled with 8b, and preliminary in vivo evaluation shown 8b could enhance the ability of liposomes delivering tegafur across the blood brain barrier. (C) 2011 Yong Wu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
In vitroandin vivoinvestigation of glucose-mediated brain-targeting liposomes
摘要:
New glycosyl derivative of cholesterol was synthesized as a material for preparing novel liposome to overcome the ineffective delivery of normal drug formulations to brain by targeting the (glucose transporters) GLUTs on the BBB. Coumarin-6 was used as fluorescent probe. The results have shown that the cytotoxicity for the brain capillary endothelial cells (BCECs) of the glucose-mediated brain targeting liposome containing coumarin-6 was less than that of conventional liposome. The BBB model in vitro was established by coculturing of BCECs and astrocytes (ACs) of rat to test the transendothelial ability crossing the BBB. The transendothelial ability was confirmed strengthen alone with the amount of the new glycosyl derivative of cholesterol used in liposome. After i.v. administration of LIP, control liposome (CLP), and GLP-4, the AUC(0-t) of coumarin-6 for GLP-4 was 2.85 times higher than that of LIP, and 3.33 times higher than that of CLP. The C-max of CLP-4 was 1.43 times higher than that of LIP, and 3.10 times higher than that of CLP. Both pharmacokinetics and distribution in mice were also investigated to show that this novel brain targeting drug delivery system was promising.