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, Jarmo Teuho, Jawad Sarfraz, Hua Jiang, Chunfu Zhang, Cecilia Sahlgren, Mika Lindén, Hongchen Gu, Jessica M. Rosenholm*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

12 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 languageEnglish
Pages (from-to)1750-1760
Number of pages11
JournalBiomaterials Science
Volume2
Issue number12
DOIs
Publication statusPublished - 1 Dec 2014
MoE publication typeA1 Journal article-refereed

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    Gulin-Sarfraz, T., Zhang, J., Desai, D., Teuho, J., Sarfraz, J., Jiang, H., Zhang, C., Sahlgren, C., Lindén, M., Gu, H., & Rosenholm, J. M. (2014). Combination of magnetic field and surface functionalization for reaching synergistic effects in cellular labeling by magnetic core-shell nanospheres. Biomaterials Science, 2(12), 1750-1760. https://doi.org/10.1039/c4bm00221k