

Title | Transition from unilamellar to bilamellar vesicles induced by an amphiphilic biopolymer. |
Publication Type | Journal Article |
Year of Publication | 2006 |
Authors | Lee, J-H, Agarwal, V, Bose, A, Payne, GF, Raghavan, SR |
Journal | Phys Rev Lett |
Volume | 96 |
Issue | 4 |
Pagination | 048102 |
Date Published | 2006 Feb 3 |
ISSN | 0031-9007 |
Keywords | Chitosan, Cryoelectron Microscopy, Hydrophobic and Hydrophilic Interactions, Lipid Bilayers, Membranes, Artificial, Phase Transition |
Abstract | We report some unusual structural transitions upon the addition of an amphiphilic biopolymer to unilamellar surfactant vesicles. The polymer is a hydrophobically modified chitosan and it embeds its hydrophobes in vesicle bilayers. We study vesicle-polymer mixtures using small-angle neutron scattering (SANS) and cryotransmission electron microscopy (cryo-TEM). When low amounts of the polymer are added to unilamellar vesicles of ca. 120 nm diameter, the vesicle size decreases by about 50%. Upon further addition of polymer, lamellar peaks are observed in the SANS spectra at high scattering vectors. We show that these spectra correspond to a co-existence of unilamellar and bilamellar vesicles. The transition to bilamellar vesicles as well as the changes in unilamellar vesicle size are further confirmed by cryo-TEM. A mechanism for the polymer-induced transitions in vesicle morphology is proposed. |
Alternate Journal | Phys. Rev. Lett. |
PubMed ID | 16486898 |