title: Water-soluble nanoparticles from random copolymer and oppositely charged surfactant, 3a. Nanoparticles of poly(ethylene glycol)-based cationic random copolymer and fatty acid salts.
abstract: In this report, we investigate the nanoparticle formation between random copolymers (RCPs) of methoxy-poly(ethylene glycol) monomethacrylate (MePEGMA) and (3-(methacryloylamino)propyl)trimethylammonium chloride (MAPTAC) and oppositely charged natural surfactants, sodium oleate and sodium laurate, using turbidimetric titration, steady-state fluorescence, dynamic light scattering, and electron microscopy. Though sodium oleate and sodium laurate are sparingly soluble in water, the nanoparticle complexes formed between the RCPs and these surfactants are soluble in the entire range of compositions studied here, including the stoichiometric electronetural complexes. The spherical nature of these nanoparticle complexes is revealed by electron microscopic (EM) analysis. Dynamic light scattering (DLS) showed that the average diameters of the nanoparticles are in the range 50 to 150 nm, which is supported by EM analysis. Pyrene fluorescence experiments suggested that these soluble nanoparticles have hydrophobic cores, which may solubilize hydrophobic drug molecules. The polarity index (I(1)/I(3)) obtained from the pyrene fluorescence spectra and the conductometric measurements showed that the critical concentration of fatty acid salts needed to obtain nanoparticles are in the order of 10(-4) M. Further, the complexation of such poorly water-soluble amphiphilic surfactants with polymers offers a useful method for the immobilization of hydrophobic compounds towards water-soluble drug carrier formulations. The formation of water-soluble nanoparticles by the self-assembly of fatty acid salts upon interacting with oppositely charged poly(ethylene glycol)-based polyions.
authors.affiliation: Department of Pathology and Lab Medicine and Centre for Blood Research, 2211 Wesbrook Mall, University of British Columbia, Vancouver, British Columbia V6T 2B5, Canada. jay@pathology.ubc.ca
authors.forename: Jayachandran N
authors.initials: JN
authors.lastname: Kizhakkedathu
authors.forename: C K
authors.initials: CK
authors.lastname: Nisha
authors.forename: Sunkara V
authors.initials: SV
authors.lastname: Manorama
authors.forename: Souvik
authors.initials: S
authors.lastname: Maiti
mesh_terms: D001647:Bile Acids and Salts; D002412:Cations; D005453:Fluorescence; D007850:Lauric Acids; D015335:Molecular Probes; D049329:Nanostructures; D019301:Oleic Acid; D011092:Polyethylene Glycols; D012967:Sodium Dodecyl Sulfate
chemical_list: D001647:Bile Acids and Salts; D002412:Cations; D007850:Lauric Acids; D015335:Molecular Probes; C030358:lauric acid; D019301:Oleic Acid; D012967:Sodium Dodecyl Sulfate; C013173:osteum; D011092:Polyethylene Glycols