(23b) Magnetic Iron Oxide Nanoparticles As a Local Source of Heat for Remotely Controlled Reaction

Magnetic
iron oxide nanoparticles as a local source of heat for remotely controlled
reaction

Ayse Beyza Aysan¹, Zdeněk
Knejzlík^1,2, Aleš Zadražil¹,
František Štěpánek¹

¹University of Chemistry and Technology,
Faculty of Chemical Engineering Department, Prague, Technicka 5, 166 28 Prague
6, Tel. +420 220444320, E-mail: aysana@vscht.cz;

²Institute of Organic Chemistry and
Biochemistry of the Czech Academy of Sciences of the Czech Republic, Flemingovo náměstí 542/2, 166 10, Prague 6

Nanomaterials have seen
considerable attention in biochemical processes due to their physical, chemical
and biomedical properties. One of the promising classes of nanomaterials are magnetic
nanoparticles with the ability to undergo down-stream modification making them biocompatible,
nontoxic, high level accumulated in the target region and acting as a local
source of heating in the presence of an radiofrequency
alternating magnetic field (RFAMF). High surface area and engineered functional groups make from the
nanoparticles an ideal tool for magnetic resonance imaging (MRI), drug/gene
carrier, tissue repair or heating mediators in hyperthermia.

The aim of the presentation is
to use the colloidal magnetic nanoparticle suspension to initiate the polymerase
chain reaction (PCR). Firstly, magnetic iron oxide nanoparticles (MNPs) were fabricated
with relevant specifications and combined with PCR mixture containing all
required components. Concordantly, we present a research about compatibility of
MNPs with the PCR components and define the conditions for an effective PCR in
the presence of high concentration of MNPs and regulate temperature cycles for
PCR by RFAMF.

MNPs were fabricated successfully with different types of
functional groups including sodium citrate dehydrate (Na₃C₆H₅O₇.2H₂O),
3-aminopropyl-triethoxysilane
(APTES) and dextran 70 (from Leuconostoc spp., approximately Mw 70 kDa). After characterization of
MNPs in terms of concentration, size distribution, surface
morphology, and radiofrequency heating ability, they were used in PCR reaction
to see the effect on the process. According to the results the response to the RF alternating magnetic field is proportional to the size
and concentration of the nanoparticles. Dextran coated MNPs were stable in the
PCR reaction mixture even in high concentration while the other types formed
aggregates in excess of 1 µm. Experiments were focused on dextran coated MNPs
in sufficiently high concentrations to achieve the required PCR temperature by
exposure to an RF alternating magnetic field. Preliminary results showed that
dextran coated MNPs in 5mg/ml concentration could increase the reaction
temperature up to 97˚C which was sufficient to start the PCR reaction
under RF alternating magnetic field.