title: Biocompatible magnetic core-shell nanocomposites for engineered magnetic tissues.
abstract: The inclusion of magnetic nanoparticles into biopolymer matrixes enables the preparation of magnetic field-responsive engineered tissues. Here we describe a synthetic route to prepare biocompatible core-shell nanostructures consisting of a polymeric core and a magnetic shell, which are used for this purpose. We show that using a core-shell architecture is doubly advantageous. First, gravitational settling for core-shell nanocomposites is slower because of the reduction of the composite average density connected to the light polymer core. Second, the magnetic response of core-shell nanocomposites can be tuned by changing the thickness of the magnetic layer. The incorporation of the composites into biopolymer hydrogels containing cells results in magnetic field-responsive engineered tissues whose mechanical properties can be controlled by external magnetic forces. Indeed, we obtain a significant increase of the viscoelastic moduli of the engineered tissues when exposed to an external magnetic field. Because the composites are functionalized with polyethylene glycol, the prepared bio-artificial tissue-like constructs also display excellent ex vivo cell viability and proliferation. When implanted in vivo, the engineered tissues show good biocompatibility and outstanding interaction with the host tissue. Actually, they only cause a localized transitory inflammatory reaction at the implantation site, without any effect on other organs. Altogether, our results suggest that the inclusion of magnetic core-shell nanocomposites into biomaterials would enable tissue engineering of artificial substitutes whose mechanical properties could be tuned to match those of the potential target tissue. In a wider perspective, the good biocompatibility and magnetic behavior of the composites could be beneficial for many other applications.
authors.affiliation: Department of Applied Physics, University of Granada, Faculty of Science, Campus de Fuentenueva, 18071 Granada, Spain. l_rodriguezarco@ugr.es modesto@ugr.es and Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Rodriguez-Arco
authors.affiliation: Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain and Department of Histology (Tissue Engineering Group), University of Granada, Faculty of Medicine, Avenida de la Investigación, 11, 18016 Granada, Spain.
authors.forename: Ismael A
authors.initials: IA
authors.lastname: Rodriguez
authors.affiliation: Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain and Department of Histology (Tissue Engineering Group), University of Granada, Faculty of Medicine, Avenida de la Investigación, 11, 18016 Granada, Spain.
authors.forename: Victor
authors.initials: V
authors.lastname: Carriel
authors.affiliation: Department of Applied Physics, University of Granada, Faculty of Science, Campus de Fuentenueva, 18071 Granada, Spain. l_rodriguezarco@ugr.es modesto@ugr.es and Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain.
authors.forename: Ana B
authors.initials: AB
authors.lastname: Bonhome-Espinosa
authors.affiliation: Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain and Department of Histology (Tissue Engineering Group), University of Granada, Faculty of Medicine, Avenida de la Investigación, 11, 18016 Granada, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Campos
authors.affiliation: Laboratory of Condensed Matter Physics, UMR No. 7336, University of Nice-Sophia Antipolis, CNRS, 28 Avenue Joseph Vallot, 06100 Nice, France.
authors.forename: Pavel
authors.initials: P
authors.lastname: Kuzhir
authors.affiliation: Department of Applied Physics, University of Granada, Faculty of Science, Campus de Fuentenueva, 18071 Granada, Spain. l_rodriguezarco@ugr.es modesto@ugr.es and Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain.
authors.forename: Juan D G
authors.initials: JD
authors.lastname: Duran
authors.affiliation: Department of Applied Physics, University of Granada, Faculty of Science, Campus de Fuentenueva, 18071 Granada, Spain. l_rodriguezarco@ugr.es modesto@ugr.es and Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain.
authors.forename: Modesto T
authors.initials: MT
authors.lastname: Lopez-Lopez
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D049109:Cell Proliferation; D005337:Fibrin; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D008280:Magnetics; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008297:Male; D008422:Materials Testing; D051379:Mice; D008854:Microscopy, Electron; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D011092:Polyethylene Glycols / Q000737:chemistry; D012685:Sepharose; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D001672:Biocompatible Materials; D058185:Magnetite Nanoparticles; D011092:Polyethylene Glycols; D005337:Fibrin; D012685:Sepharose