Combination of magnetic field and surface functionalization for reaching synergistic effects in cellular labeling by magnetic core-shell nanospheres

Tina Gulin-Sarfraz, Jixi Zhang, Diti Desai, J Teuho, Jawad Sarfraz, H Jiang, C Zhang, Cecilia Sahlgren, M Lindén, Gu H, Jessica Rosenholm

    Research output: Contribution to journal › Article › Scientific › peer-review

    16 Citations (Scopus)

    Abstract

    Aimed at utilizing high-magnetization nanospheres for magnetic field-enhanced cellular labeling, core–shell structured sandwich-like magnetic mesoporous silica nanospheres were developed. While the magnetite cluster core can provide a high magnetic response for overcoming Brownian motion in cell culture media, the layered silica shell facilitates an efficient fluorescent dye labeling. However, the problem of particle aggregation in cell media, which is strongly enhanced under a magnetic field, significantly impeded the uptake by cells, resulting in difficulties in the precise analysis of the degree of particle internalization by fluorescence-based techniques (flow cytometry and confocal microscopy). To overcome this, reflection-based assessment was employed. Further, emphasis was put on utilizing the unique role of surface-hyperbranched polyethylenimine (PEI) in efficient prevention of particle aggregation prior to cell internalization in the presence of an external magnetic field. The interparticle attraction forces originating from magnetic dipole–dipole interactions are hereby balanced by the steric and electrostatic repulsion forces provided by the PEI functionalization, which leads to dispersed nanospheres in cell culture media during the magnetic-field induced cell labeling. As a consequence, PEI functionalization and the presence of the magnetic field synergistically enhanced the efficiency of MRI-fluorescence dual-mode labeling for cellular tracking.
    Original languageUndefined/Unknown
    Pages (from-to)1750–1760
    JournalBiomaterials Science
    Volume2
    Issue number12
    DOIs
    Publication statusPublished - 2014
    MoE publication typeA1 Journal article-refereed

    Funding

    The Graduate School of Åbo Akademi University (TG-S), Magnus Ehrnrooth Foundation (JZ), Centre for International Mobility CIMO (DD), the European Regional Development Fund in South Finland (JS), TEKES (the Finnish Funding Agency for Technology and Innovation) NAMI (China-Finland Nanotechnology Strategic Mutual Collaboration Initiative) project #19807 (TG-S, ML, JMR) and Academy of Finland project decisions #131034 (CS), #137101/140193/260599/278812 (JMR) are gratefully acknowledged for financial support. The MRI part of the study was conducted within the Finnish Center of Excellence in Molecular Imaging in Cardiovascular and Metabolic Research and strategic Japanese-Finnish research cooperative program on “Application of Medical ICT Devices” supported both by the Academy of Finland, University of Turku, Turku University Hospital and Åbo Akademi University (JT). Helena Saarento is acknowledged for kind help with cell culture preparation. We would also like to acknowledge the assistance by Jouko Sandholm at Cell Imaging Core, Turku Centre of Biotechnology, during confocal microscopy imaging; Markus Peurla from Laboratory of Electron Microscopy University of Turku during the TEM characterization; and the assistance by Jyrki Juhanoja at Top Analytica Oy Ab during the SEM characterization. This work made as well use of the Aalto University Nanomicroscopy Center (Aalto-NMC) premises.

    Access to Document

    Cite this