title: Temperature and magnetism bi-responsive molecularly imprinted polymers: Preparation, adsorption mechanism and properties as drug delivery system for sustained release of 5-fluorouracil.
abstract: Temperature and magnetism bi-responsive molecularly imprinted polymers (TMMIPs) based on Fe3O4-encapsulating carbon nanospheres were prepared by free radical polymerization, and applied to selective adsorption and controlled release of 5-fluorouracil (5-FU) from an aqueous solution. Characterization results show that the as-synthesized TMMIPs have an average diameter of about 150 nm with a typical core-shell structure, and the thickness of the coating layer is approximately 50 nm. TMMIPs also displayed obvious magnetic properties and thermo-sensitivity. The adsorption results show that the prepared TMMIPs exhibit good adsorption capacity (up to 96.53 mg/g at 25 °C) and recognition towards 5-FU. The studies on 5-FU loading and release in vitro suggest that the release rate increases with increasing temperature. Meanwhile, adsorption mechanisms were explored by using a computational analysis to simulate the imprinted site towards 5-FU. The interaction energy between the imprinted site and 5-FU is -112.24 kJ/mol, originating from a hydrogen bond, Van der Waals forces and a hydrophobic interaction between functional groups located on 5-FU and a NIPAM monomer. The electrostatic potential charges and population analysis results suggest that the imprinted site of 5-FU can be introduced on the surface of TMMIPs, confirming their selective adsorption behavior for 5-FU.
authors.affiliation: Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024, China; Research Center on Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024, China.
authors.forename: Longfei
authors.initials: L
authors.lastname: Li
authors.affiliation: Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024, China; Research Center on Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.affiliation: Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024, China; College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024, China; Research Center on Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024, China. Electronic address: yyztyut@126.com.
authors.forename: Yongzhen
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024, China; College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China. Electronic address: liuxuguang@tyut.edu.cn.
authors.forename: Xuguang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024, China; University of Hertfordshire, School of Engineering and Technology, Hatfield, Hertfordshire AL10 9AB, UK.
authors.forename: Yongkang
authors.initials: Y
authors.lastname: Chen
mesh_terms: D003692:Delayed-Action Preparations / Q000737:chemistry / Q000494:pharmacology; D005472:Fluorouracil / Q000737:chemistry* / Q000493:pharmacokinetics; D006358:Hot Temperature; D060526:Magnetic Fields
chemical_list: D003692:Delayed-Action Preparations; D005472:Fluorouracil
keywords: Drug delivery system; Imprinted site; Magnetism; Molecular imprinting technique; Simulate; Temperature-sensitivity