Magnetic Surfactants and Polymers with Gadolinium Counterions for Protein Separations

• Published in: Langmuir Vol. 32; no. 3; pp. 699 - 705
• Main Authors: Brown, Paul, Bromberg, Lev, Rial-Hermida, M. Isabel, Wasbrough, Matthew, Hatton, T. Alan, Alvarez-Lorenzo, Carmen
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 26.01.2016
• Subjects: Animals; Cations; Cetrimonium Compounds - chemistry; Chemical Fractionation - methods; CHO Cells; Cricetulus; Electric Conductivity; Electrophoresis, Polyacrylamide Gel; Gadolinium - chemistry; Humans; Insulin-Like Growth Factor II - isolation & purification; Lipoprotein(a) - isolation & purification; Magnetic Fields; Magnets; Organometallic Compounds - chemistry; Serum Albumin - isolation & purification; Surface Tension; Surface-Active Agents - chemistry
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/acs.langmuir.5b04146

New magnetic surfactants, (cationic hexadecyltrimethlyammonium bromotrichlorogadolinate (CTAG), decyltrimethylammonium bromotrichlorogadolinate (DTAG), and a magnetic polymer (poly­(3-acrylamidopropyl)­trimethylammonium tetrachlorogadolinate (APTAG)) have been synthesized by the simple mixing of the corresponding surfactants and polymer with gadolinium metal ions. A magnetic anionic surfactant, gadolinium tri­(1,4-bis­(2-ethylhexoxy)-1,4-dioxobutane-2-sulfonate) (Gd­(AOT)3), was synthesized via metathesis. Both routes enable facile preparation of magnetically responsive magnetic polymers and surfactants without the need to rely on nanocomposites or organic frameworks with polyradicals. Electrical conductivity, surface tensiometry, SQUID magnetometry, and small-angle neutron scattering (SANS) demonstrate surface activity and self-aggregation behavior of the magnetic surfactants similar to their magnetically inert parent analogues but with added magnetic properties. The binding of the magnetic surfactants to proteins enables efficient separations under low-strength (0.33 T) magnetic fields in a new, nanoparticle-free approach to magnetophoretic protein separations and extractions. Importantly, the toxicity of the magnetic surfactants and polymers is, in some cases, lower than that of their halide analogues.