title: Immobilization of hydrophilic low molecular-weight molecules in nanoparticles of chitosan/poly(sodium 4-styrenesulfonate) assisted by aromatic-aromatic interactions.
abstract: The immobilization of the hydrophilic low molecular-weight cationic molecules rhodamine 6G, methylene blue, and citidine in nanoparticles composed of two opposite charged polyelectrolytes, poly(sodium 4-styrenesulfonate) and chitosan, is studied, and the results correlated with their physicochemical properties. Nanoparticles containing both polyelectrolytes have been synthesized showing hydrodynamic diameters of around 200 nm and tunable zeta potential. It was found that the strength of binding of the cationic molecules to the polyanion bearing charged aromatic groups poly(sodium 4-styrenesulfonate) by means of short-range aromatic-aromatic interactions increases with their hydrophobicity and polarizability, as seen by (1)H NMR and UV-vis spectroscopies, and diafiltration. Consequently, association efficiencies of 45, 21, and 12% have been found for the three molecules, respectively, revealing the different ability of the molecules to be immobilized in the nanoparticles. These results provide a proof of concept on a new strategy of immobilization of hydrophilic low molecular-weight molecules based on aromatic-aromatic interactions between polyelectrolytes and their aromatic counterions.
authors: IBBP, Westfälische Wilhelms-Universität Münster , Schlossgarten 3, 48149 - Münster, Germany.
authors: Juan Pablo
authors: JP
authors: Fuenzalida
authors: Mario E
authors: ME
authors: Flores
authors: Inés
authors: I
authors: Móniz
authors: Miguel
authors: M
authors: Feijoo
authors: Francisco
authors: F
authors: Goycoolea
authors: Hiroyuki
authors: H
authors: Nishide
authors: Ignacio
authors: I
authors: Moreno-Villoslada
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D008970:Molecular Weight; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry*
chemical_list: D011108:Polymers; D013451:Sulfonic Acids; D048271:Chitosan; C077114:styrenesulfonic acid polymer