title: Magnetic Biocomposites for Remote Melting.
abstract: A new approach toward the fabrication of biocompatible composites suitable for remote melting is presented. It is shown that magnetite nanoparticles (MNP) can be embedded into a matrix of biocompatible thermoplastic dextran esters. For that purpose, fatty acid esters of dextran with adjustable melting points in the range of 30-140 °C were synthesized. Esterification of the polysaccharide by activation of the acid as iminium chlorides guaranteed mild reaction conditions leading to high quality products as confirmed by FTIR- and NMR spectroscopy as well as by gel permeation chromatography (GPC). A method for the preparation of magnetically responsive bionanocomposites was developed consisting of combined dissolution/suspension of the dextran ester and hydrophobized MNPs in an organic solvent followed by homogenization with ultrasonication, casting of the solution, drying and melting of the composite for a defined shaping. This process leads to a uniform distribution of MNPs in nanocomposite as revealed by scanning electron microscope. Samples of different geometries were exposed to high frequency alternating magnetic field. It could be shown that defined remote melting of such biocompatible nanocomposites is possible for the first time. This may lead to a new class of magnetic remote control systems, which are suitable for controlled release applications or self-healing materials.
authors.affiliation: †Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstrasse 10, D-07743 Jena, Germany.
authors.forename: Mengbo
authors.initials: M
authors.lastname: Zhou
authors.affiliation: †Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstrasse 10, D-07743 Jena, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Liebert
authors.affiliation: ‡Leibniz-Institute of Photonic Technology e.V. (IPHT), Postfach 100239, D-07702 Jena, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Müller
authors.affiliation: ‡Leibniz-Institute of Photonic Technology e.V. (IPHT), Postfach 100239, D-07702 Jena, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Dellith
authors.affiliation: §Department Hematology/Oncology, Jena University Hospital, Friedrich Schiller University of Jena, Erlanger Allee 101, D-07747 Jena, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Gräfe
authors.affiliation: §Department Hematology/Oncology, Jena University Hospital, Friedrich Schiller University of Jena, Erlanger Allee 101, D-07747 Jena, Germany.
authors.forename: Joachim H
authors.initials: JH
authors.lastname: Clement
authors.affiliation: †Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstrasse 10, D-07743 Jena, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Heinze
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D003911:Dextrans / Q000737:chemistry; D004952:Esters / Q000737:chemistry; D005615:Freezing; D006801:Humans; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D044366:Transition Temperature
chemical_list: D001672:Biocompatible Materials; D003911:Dextrans; D004952:Esters; D058185:Magnetite Nanoparticles