Nanocomposites and nanomaterials

Pt-coated magnetite core-shell nanoparticles for controlled promoting of the lipid peroxidation
Lavrynenko O.M., Pavlenko O.Yu., Shchukin Yu.S.
Institute for Problems in Material Science, NAS of Ukraine,
3 Krzhizhanovsky St., Kyiv-03680, Ukraine, 
E-mail: alena.lavrynenko@gmail.com

Among the core&shell type nanocompsites the structures based on iron oxide and precious metals play an important role in new medical products development due to the combination of magnetic properties of cores and optical properties of the shells [1, 2]. Nowadays, platinum-bearing compounds (cis-platin and its derivatives) are widely used as anti-tumor agents. In particular, Pt-containing core&shell structures are recognized as more effective pharmaceutical composition than cis-platin. Generally, such structures show low toxicity and the reversal of multidrug resistance as well. In addition, due to the release of Fe2+ from the particles the catalytical decomposition of peroxides into reactive oxygen species within tumor cells causes oxidative deterioration of cellular membrane and cell death.
Nanocomposite particles were formed on the steel surface in the open-air system in the presence of Na2[PtCl4] water solution at c(Pt2+)= 10 mg·dm-3. They consisted of 20 nm magnetite cores coated by platinum shells up to 0.14 mass.% and showed core-associated superparamagnetic properties. The lipid peroxidation activity of FeFe2O4&Pt0 nanocomposites were studied by the means of coumarin-enhanced chemiluminescence in 5·10-4 mg·dm-3 lecithin suspension at pH=7.4, adding 1mM EDTA-sodium for ferrous species elimination in reference probes. The as-prepared FeFe2O4&Pt0 nanoparticles demonstrated evident ability to promote lipid peroxidation depending on the concentration of nanocomposite sol. 
So, the ability of FeFe2O4&Pt0 to promote lipid peroxidation due to the release of ferrous species from sol could offer a new platform for targeted antitumor therapy.

1.	He Q.G., Wu Z.H., Hu R. Platinum immobilization on iron oxide nanoparticles surface under sonication // Adv. Mater. Res.-2011. -183–185.-P. 1989–1994.
2.	Lavrynenko O.M, Dolynskyi G.A. Core&shell type nanocomposites (iron oxide-precious metal): synthesis, structure, properties. and bio-medical application. A review  // Material Science of Nanostructures.-2011.-3.-P. 3-34. (in Russian)