title: Highly Efficient Thermoresponsive Nanocomposite for Controlled Release Applications.
abstract: Highly efficient magnetic release from nanocomposite microparticles is shown, which are made of Poly (N-isopropylacrylamide) hydrogel with embedded iron nanowires. A simple microfluidic technique was adopted to fabricate the microparticles with a high control of the nanowire concentration and in a relatively short time compared to chemical synthesis methods. The thermoresponsive microparticles were used for the remotely triggered release of Rhodamine (B). With a magnetic field of only 1 mT and 20 kHz a drug release of 6.5% and 70% was achieved in the continuous and pulsatile modes, respectively. Those release values are similar to the ones commonly obtained using superparamagnetic beads but accomplished with a magnetic field of five orders of magnitude lower power. The high efficiency is a result of the high remanent magnetization of the nanowires, which produce a large torque when exposed to a magnetic field. This causes the nanowires to vibrate, resulting in friction losses and heating. For comparison, microparticles with superparamagnetic beads were also fabricated and tested; while those worked at 73 mT and 600 kHz, no release was observed at the low field conditions. Cytotoxicity assays showed similar and high cell viability for microparticles with nanowires and beads.
authors.affiliation: Computer, Electrical and Mathematical Sciences &Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Omar
authors.initials: O
authors.lastname: Yassine
authors.affiliation: School of Engineering, University of British Columbia, 3333 University Way, Kelowna, BC, V1V 1V7, Canada.
authors.forename: Amir
authors.initials: A
authors.lastname: Zaher
authors.affiliation: Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Er Qiang
authors.initials: EQ
authors.lastname: Li
authors.affiliation: Computer, Electrical and Mathematical Sciences &Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Alfadhel
authors.affiliation: Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Jose E
authors.initials: JE
authors.lastname: Perez
authors.affiliation: Computer, Electrical and Mathematical Sciences &Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Mincho
authors.initials: M
authors.lastname: Kavaldzhiev
authors.affiliation: Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Maria F
authors.initials: MF
authors.lastname: Contreras
authors.affiliation: Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Sigurdur T
authors.initials: ST
authors.lastname: Thoroddsen
authors.affiliation: Smart Hybrid Materials Laboratory, Advanced Membranes and Porous Materials Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Niveen M
authors.initials: NM
authors.lastname: Khashab
authors.affiliation: Computer, Electrical and Mathematical Sciences &Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Jurgen
authors.initials: J
authors.lastname: Kosel