title: Near-infrared light-triggered dissociation of block copolymer micelles using upconverting nanoparticles.
abstract: We demonstrate a novel strategy enabling the use of a continuous-wave diode near-infrared (NIR) laser to disrupt block copolymer (BCP) micelles and trigger the release of their "payloads". By encapsulating NaYF(4):TmYb upconverting nanoparticles (UCNPs) inside micelles of poly(ethylene oxide)-block-poly(4,5-dimethoxy-2-nitrobenzyl methacrylate) and exposing the micellar solution to 980 nm light, photons in the UV region are emitted by the UCNPs, which in turn are absorbed by o-nitrobenzyl groups on the micelle core-forming block, activating the photocleavage reaction and leading to the dissociation of BCP micelles and release of co-loaded hydrophobic species. Our strategy of using UCNPs as an internal UV or visible light source upon NIR light excitation represents a general and efficient method to circumvent the need for UV or visible light excitation that is a common drawback for light-responsive polymeric systems developed for potential biomedical applications.
authors.affiliation: Département de chimie, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K2R1.
authors.forename: Bin
authors.initials: B
authors.lastname: Yan
authors.forename: John-Christopher
authors.initials: JC
authors.lastname: Boyer
authors.forename: Neil R
authors.initials: NR
authors.lastname: Branda
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D007259:Infrared Rays; D008027:Light; D008689:Methacrylates / Q000737:chemistry; D008823:Micelles; D053758:Nanoparticles / Q000737:chemistry*; D010782:Photolysis; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*
chemical_list: D008689:Methacrylates; D008823:Micelles; D011108:Polymers; D011092:Polyethylene Glycols