Open AccessMicellization and Single-Particle Encapsulation with Dimethylammoniopropyl Sulfobetaines
Author(s) -
Jianxin Wang,
Oscar MoralesCollazo,
Alexander Wei
Publication year - 2017
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.7b00288
Subject(s) - micelle , amphiphile , chemical engineering , particle size , alkyl , colloid , aqueous solution , nanoparticle , chemistry , ionic strength , materials science , nanotechnology , organic chemistry , polymer , copolymer , engineering
Sulfobetaines (SBs) are a class of zwitterionic surfactants with a reputation for enhancing colloidal stability at high salt concentrations. Here, we present a systematic study on the self-assembly of SB amphiphiles (sultaines or hydroxysultaines) in aqueous solutions, as a function of chain length and composition, ionic strength, and in the presence of alkanethiol-coated Au nanoparticles (GNPs). The diameters of the micelles assembled from SB and amidosulfobetaine (ASB) generally increase monotonically with chain length, although ASB micelles are smaller relative to alkyl SB micelles with similarly sized tailgroups, and oleyl sulfobetaine (OSB) micelles are slightly larger. SB amphiphiles can stabilize alkanethiol-coated GNPs in physiologically relevant buffers at concentrations well below their CMC, with size increases corresponding to single-particle encapsulation. SB-encapsulated GNPs were prepared by three different methods with SB:GNP weight ratios of 10:1, followed by dispersion in water or 1 M NaCl. The low hydrodynamic size of the SB micelles and SB-coated NPs is within the range needed for efficient renal clearance.