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Composite Microspheres for Separation of Plasmid DNA Decorated with MNPs through in Situ Growth or Interfacial Immobilization Followed by Silica Coating
journal contribution
posted on 2012-09-26, 00:00 authored by Shuai Xu, Xiaojie Song, Jia Guo, Changchun WangRaspberry-like colloidal polymer/magnetite/silica composite
microspheres
were rationally fabricated based on in situ growth or interfacial
immobilization of magnetic nanoparticles (MNPs) onto the polymer matrices
and the followed sol–gel coating process. Monodisperse cross-linked
poly(styrene-co-glycidyl methacrylate) microspheres were first prepared
by surfactant-free emulsion polymerization, followed by surface modification
of carboxyl or amine moieties through thiol-epoxy click chemistry.
Then the carboxyl-modified microspheres were in situ decorated with
MNPs through solvothermal process or chemical coprecipitation reaction.
In parallel, incorporation of MNPs onto polymer matrices was also
realized by the interaction of amine-modified polymer microspheres
with carboxyl-capped MNPs based on the electrostatic interaction.
The two pathways for synthesis of the composite microspheres decorated
with MNPs were systematically investigated. Furthermore, the composite
microspheres were coated with a thin layer of silica through a sol–gel
process. The thus-produced magnetic composite microspheres with desirable
magnetization (∼23 emu/g) served as effective supports for
high-payload plasmid DNA enrichment (∼17 μg per mg of
microspheres), much better than that of the commercial-available sample
of SM1–015B (∼12 μg per mg of SM1–015B),
shedding lights on the potential advantages of the nanoplatforms for
separation of bioactive entities.