title: Microgels loaded with gold nanorods: photothermally triggered volume transitions under physiological conditions.
abstract: Photothermally driven volume transitions in polymer microgels have promising applications for site-specific drug delivery and photodynamic therapy. We studied the temperature-induced volume phase transitions for a series of thermoresponsive microgels of various compositions to find a system with a sharp transition in the physiologically relevant range spanning 38-41 degrees C in 0.01 M phosphate-buffered saline solution (pH = 7.4). We found that the poly(N-isopropylacrylamide-maleic acid) microgels showed an 8-fold decrease in size under the aforementioned conditions. These microgels were loaded with gold nanorods designed to absorb in the near-IR spectral range. Following irradiation at lambda = 809 nm, the microgels underwent a large, reversible, photothermally triggered change in volume. We believe that this microgel system is a promising candidate for photothermally controlled drug release.
authors.affiliation: Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, ON M5S 3H6, Canada.
authors.forename: Mallika
authors.initials: M
authors.lastname: Das
authors.forename: Nicolas
authors.initials: N
authors.lastname: Sanson
authors.forename: Daniele
authors.initials: D
authors.lastname: Fava
authors.forename: Eugenia
authors.initials: E
authors.lastname: Kumacheva