Spontaneous Self-Assembly of Thermoresponsive Vesicles Using a Zwitterionic and an Anionic SurfactantShow others and affiliations
2020 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 21, no 11, p. 4569-4576Article in journal (Refereed) Published
Abstract [en]
Spontaneous formation of vesicles from the self-assembly of two specific surfactants, one zwitterionic (oleyl amidopropyl betaine, OAPB) and the other anionic (Aerosol-OT, AOT), is explored in water using small-angle scattering techniques. Two factors were found to be critical in the formation of vesicles: surfactant ratio, as AOT concentrations less than equimolar with OAPB result in cylindrical micelles or mixtures of micellar structures, and salt concentration, whereby increasing the amount of NaCl promotes vesicle formation by reducing headgroup repulsions. Small-angle neutron scattering measurements reveal that the vesicles are approximately 30-40 nm in diameter, depending on sample composition. Small-angle X-ray scattering measurements suggest preferential partitioning of OAPB molecules on the vesicle inner layer to support vesicular packing. Heating the vesicles to physiological temperature (37 °C) causes them to collapse into smaller ellipsoidal micelles (2-3 nm), with higher salt concentrations (≥10 mM) inhibiting this transition. These aggregates could serve as responsive carriers for loading or unloading of aqueous cargoes such as drugs and pharmaceuticals, with temperature changes serving as a simple release/uptake mechanism.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2020. Vol. 21, no 11, p. 4569-4576
National Category
Physical Chemistry
Identifiers
URN: urn:nbn:se:mau:diva-18016DOI: 10.1021/acs.biomac.0c00672ISI: 000592221000016PubMedID: 32597638Scopus ID: 2-s2.0-85095861687OAI: oai:DiVA.org:mau-18016DiVA, id: diva2:1458791
2020-08-182020-08-182024-06-17Bibliographically approved