Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 7, pp. 10831089.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © I.N. Voevodina, Ya.Yu. Marchenko, B.P. Nikolaev, L.Yu. Yakovleva, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85,
No. 7, pp. 11141120.
OF SYSTEMS AND PROCESSES
Synthesis and Magnetic Relaxation Properties
of a Porous Glass Magnetic Microcarrier
I. N. Voevodina, Ya. Yu. Marchenko, B. P. Nikolaev, and L. Yu. Yakovleva
State Research Institute of Highly Pure Biopreparations, Federal Medical-Biological Agency, St. Petersburg, Russia
eceived April 6, 2012
Abstract—The reaction of formation of magnetic iron oxide nanoparticles from aqueous solutions of Fe(+2,+3)
salts was studied under homo- and heterophase conditions of capillary-porous bodies by the nuclear magnetic
resonance relaxometry method. Magnetic composites based on Bio-Glas porous glasses were obtained by pre-
cipitation of iron oxide nanoparticles in pores ranging in size from 50 to 250 nm. The magnetic relaxation rate of
water protons during the heterophase precipitation reaction was examined.
Magnetic microcrriers are extensively used in biotech-
nology for isolation of bioactive compounds, separation
of cells from culture ﬂ uids, and puriﬁ cation of proteins
and nucleic acids and also serve as key elements of
biosensor devices . Widespread application of MRI
examinations into the health care practice has stimulated
additional interest in micro- and nanocarriers as a means
to enhance the magnetic contrast and, thereby, improve
the quality of images of internal organs, provided by
this noninvasive imaging technique. In this context, of
particular interest are magnetic microcarriers containing
superparamagnetic iron oxide nanoparticles. The occur-
rence of iron atoms in the speciﬁ c superparamagnetic
state of small-sized nanoparticles imparts to microcar-
riers a number of physical properties which allow their
convenient application. Due to lacking hysteresis, high
speciﬁ c magnetization, and easy preparation, superpara-
magnetic nanoparticles have gained widespread use in
preparation of magnetic composite materials. The avail-
able information on synthesis of magnetic microcarriers
of this type refers mostly to polymeric microspheres
based on ﬂ exible-chain polymers, which are prepared by
the emulsion polymerization technique in the presence
of beforehand introduced magnetic nanoparticles [2, 3].
The major synthesis route to nanocomposites consists
in preparation of free nanoparticles to be subsequently
incorporated into an inert matrix . A useful method
for magnetization of the already formed microspheres
by superparamagnetic nanoparticles consists in diffusion
precipitation of nanoparticles from metal salt solutions.
Formation of magnetic nanoparticles inside the sorbent
pores from solutions of chemicals penetrating through
the outside boundary of the microcarrier is described in
terms of the complex mass-exchange model. Depending
on the synthesis conditions, a magnetic material layer can
be formed, in principle, to make the center of the micro-
carrier inaccessible to the liquid phase. The choice of a
version of this heterogeneous reaction in each particular
is dictated by the speciﬁ c task to be performed.
Magnetic composites based on Bio-Glas porous
glasses are attractive for application in preparative and
analytical high-pressure liquid chromatography of pro-
teins . It should be noted that Bio-Glas glasses rep-
resent a sorption material that can resist high pressures,
and t he commercially available chemical endowed with
magnetic properties allows easier separation of proteins
by the elution procedure.
Here, we examined the possibility of preparation of