Vesicle formed by amphiphilc cucurbit[6]uril: versatile, noncovalent modification of the vesicle surface, and multivalent binding of sugar-decorated vesicles to lectin.
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.
Lee
Hyung-Kun
HK
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.
Park
Kyeng Min
KM
Jeon
Young Jin
YJ
Kim
Dongwoo
D
Oh
Dong Hyun
DH
Kim
Hyung Seok
HS
Park
Chan Kyung
CK
Kim
Kimoon
K
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
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