Phase behavior, microstructure and cytotoxicity in mixtures of a charged triblock copolymer and an ionic surfactant. (February 2016)

• Record Type: Journal Article
• Authors: Claro, Bárbara; Zhu, Kaizheng; Bagherifam, Shahla; Silva, Sandra G.; Griffiths, Gareth; Knudsen, Kenneth D.; Marques, Eduardo F.; Nyström, Bo
• Is Part Of: European polymer journal. Volume 75(2016:Feb.)
• Page Start: 461
• Page End: 473
• Publication Date: 2016-02
• Subjects: Surfactant -- Amphiphilic block copolymer -- Micelles -- Phase behavior -- Drug delivery; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2016.01.018
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: Temperature-responsive copolymer interacts with anionic- and cationic surfactant. Binding of ionic surfactant to the copolymer increases the cloud point of sample. The zeta-potential changes strongly by adding SDS or DTAB to the copolymer. SANS data show that the scattering profile can be portrayed by a core–shell model. Abstract: In the present study, aqueous solutions of a thermo-responsive negatively charged triblock copolymer methoxy-poly(ethylene glycol)- block -poly( N -isopropylacrylamide)- block -poly(2-succinic acid-propyloxyl methacrylate) (MPEG45 - b -PNIPAAM48 - b -PSAPMA10 ), have been characterized in the presence of sodium dodecyl sulfate (SDS) or dodecyltrimethylammonium bromide (DTAB) surfactant, at a constant concentration of polymer and various levels of surfactant addition. For this purpose, dynamic light scattering (DLS) was used to probe the effect of the ionic surfactants on the size of the block copolymer species, and small-angle neutron scattering (SANS) was applied as a complementary technique to probe the structure on a mesoscopic length scale. The results obtained revealed that the addition of a surfactant to the copolymer solution leads to a decrease of the particle size, due to electrostatic repulsions and solubilization of the hydrophobic microdomains. By zeta potential analysis it was shown that the charge density of the surfactant-coated polymer moieties increases with increasing surfactant concentration. The turbidities of the polymer–surfactant mixtures were measured using a cloud point analyzer. Our data revealed that the behavior not only depends on the surfactant concentration, but it is also affected in some cases by temperature. In addition, cytotoxicity studies were carried out on mouse fibroblasts cells NIH–3T3 to evaluate the potential of the systems as drug delivery carriers. Results showed that the cytotoxicity of the polymer changes with surfactant addition, rising as the concentration of SDS increases but falling off with increasing DTAB concentration.