title: Vesicle formed by amphiphilc cucurbit[6]uril: versatile, noncovalent modification of the vesicle surface, and multivalent binding of sugar-decorated vesicles to lectin.
abstract: We report a novel vesicle formed by an amphiphilic CB[6] derivative, the surface of which can be easily modified via host-guest interactions by taking advantage of molecular cavities, readily accessible at the vesicle surface, and their strong affinity toward polyamines. Amphiphilic CB[6] derivative 1 synthesized by reaction between (allyloxy)12CB[6] and 2-[2-(2-methoxyethoxy)ethoxy]ethanethiol affords a vesicle that has been characterized by TEM, light scattering, and fluorescent dye entrapment experiments. Treatment of vesicle 1 with FITC (fluorescein isothiocyanate)-spermine conjugate ligand 2, in which spermine serves as a binding motif to CB[6] and FITC as a fluorescent tag, produced a surface-modified vesicle, which can be easily visualized by a confocal microscope. This result provides us with a new noncovalent, modular approach to the modification of vesicle surfaces. By treating the vesicle derived from the amphiphilic CB[6] with a tag-attached polyamine, we can easily decorate the surface of the vesicle with the tag. Sugar-decorated vesicles were prepared by this noncovalent method, and their interactions with concanavalin A (ConA) were studied. The binding constant of the vesicle decorated with mannose-spermidine conjugate 3 to ConA was measured to be approximately 3 x 104 M-1, which is almost 3 orders of magnitude higher than that of free ligand 3 to ConA (K = approximately 50 M-1). On the other hand, the binding constant of the vesicle coated with galactose-spermidine conjugate 4 to ConA was too small to be measured. These results illustrate the specific and multivalent interactions between the mannose-decorated vesicle and ConA. The ability for facile surface modification suggests many practical applications, including its use in targeted drug delivery and immunization.
authors.affiliation: National Creative Research Initiative Center for Smart Supramolecules, and Department of Chemistry, Pohang University of Science and Technology, San 31 Hyojadong, Pohang 790-784, Republic of Korea.
authors.forename: Hyung-Kun
authors.initials: HK
authors.lastname: Lee
authors.forename: Kyeng Min
authors.initials: KM
authors.lastname: Park
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Jeon
authors.forename: Dongwoo
authors.initials: D
authors.lastname: Kim
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Oh
authors.forename: Hyung Seok
authors.initials: HS
authors.lastname: Kim
authors.forename: Chan Kyung
authors.initials: CK
authors.lastname: Park
authors.forename: Kimoon
authors.initials: K
authors.lastname: Kim
mesh_terms: D001952:Bridged-Ring Compounds / Q000737:chemistry*; D003208:Concanavalin A / Q000737:chemistry*; D016503:Drug Delivery Systems; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry*; D007700:Kinetics; D008358:Mannose / Q000737:chemistry*; D013095:Spermidine / Q000737:chemistry; D013096:Spermine / Q000737:chemistry; D020349:Surface Plasmon Resonance; D013499:Surface Properties; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils
chemical_list: D001952:Bridged-Ring Compounds; D003208:Concanavalin A; D016650:Fluorescein-5-isothiocyanate; D007093:Imidazoles; D008358:Mannose; D013095:Spermidine; D013096:Spermine; C454805:cucurbit(6)uril; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils