title: Self-assembly behaviors of thermal- and pH- sensitive magnetic nanocarriers for stimuli-triggered release.
abstract: In the present work, we prepare thermo- and pH-sensitive polymer-based nanoparticles incorporating with magnetic iron oxide as the remote-controlled, stimuli-response nanocarriers. Well-defined, dual functional tri-block copolymer poly[(acrylic acid)-block-(N-isopropylacrylamide)-block-(acrylic acid)], was synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization with S,S'-bis(α,α'-dimethyl-α″-acetic acid)trithiocarbonate (CMP) as a chain transfer agent (CTA). With the aid of using 3-aminopropyltriethoxysilane, the surface-modified iron oxides, Fe3O4-NH2, was then attached on the surface of self-assembled tri-block copolymer micelles via 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride/N-hydroxysuccinamide (EDC/NHS) crosslinking method in order to furnish not only the magnetic resources for remote control but also the structure maintenance for spherical morphology of our nanocarriers. The nanocarrier was characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible (UV/Vis) spectral analysis. Rhodamine 6G (R6G), as the modeling drugs, was encapsulated into the magnetic nanocarriers by a simple swelling method for fluorescence-labeling and controlled release monitoring. Biocompatibility of the nanocarriers was studied via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which revealed that neither the pristine nanocarrier nor the R6G-loaded nanocarriers were cytotoxic to the normal fibroblast cells (L-929 cells). The in vitro stimuli-triggered release measurement showed that the intelligent nanocarriers were highly sensitive to the change of pH value and temperature rising by the high-frequency magnetic field (HFMF) treatment, which provided the significant potential to apply this technology to biomedical therapy by stimuli-responsive controlled release.
authors.affiliation: Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Chih-Yu
authors.initials: CY
authors.lastname: Kuo
authors.affiliation: Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan.
authors.forename: Ting-Yu
authors.initials: TY
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
authors.forename: Andri
authors.initials: A
authors.lastname: Hardiansyah
authors.affiliation: Department of Cosmetic Science and Institute of Cosmetic Science, Chia Nan University of Pharmacy and Science, Tainan 71710, Taiwan.
authors.forename: Chia-Fen
authors.initials: CF
authors.lastname: Lee
authors.affiliation: Department of Chemical Engineering & Biotechnology, National Taipei University of Technology, Taipei 10608, Taiwan.
authors.forename: Man-Sheng
authors.initials: MS
authors.lastname: Wang
authors.affiliation: Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan ; Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan ; Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Wen-Yen
authors.initials: WY
authors.lastname: Chiu
keywords: Magnetic nanocarriers; Poly(acrylic acid-b-[N-isopropylacrylamide]-b- acrylic acid); Stimuli-triggered drug release; Tri-block copolymer; pH- and thermo- responsive polymer