Nanobiotechnology for health-care
A new star-like thermosensitive copolymer as an effective carrier of chemotherapeutic drug doxorubicin

S. Ponomarenko1, Yu. Kuziv1, P. Virych1, V. Chumachenko1, V. Sokolova2, 
S. Prylutska1, N. Kutsevol1, Yu. Prylutskyy1, M. Epple2, U. Ritter3

1Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64, 01601 Kyiv, Ukraine.
E-mail: prylut@ukr.net
2University of Duisburg-Essen, University Str., 5-7, 45117 Essen, Germany.
3Technical University of Ilmenau, Institute of Chemistry and Biotechnology, Weimarer Str., 25, 98693 Ilmenau, Germany.

        A new water-soluble star-like thermosensitive copolymer, namely Dextran-graft-Poly-N-iso-Propilacrylamide (D-g-PNІPАМ), was created that is confirmed by size-exclusion chromatography and differential scanning calorimetry. The viability of cancer cell line (human transformed cervix epithelial cells, HeLa, as model for cancer cells) was studied using MTT and Live/Dead assays after incubation with D-g-PNІPАМ copolymer as a carrier for drug, doxorubicin (Dox), as well as their D-g-PNIPAM+Dox mixture, as a function of the concentration. FTIR spectroscopy clearly indicates the complex formation of Dox with the D-g-PNIPAM copolymer. The size distribution of particles in Hank’s solution was determined by dynamic light scattering technique at different temperatures. The in vitro uptake of the studied D-g-PNIPAM+Dox nanoparticles into cancer cells was demonstrated by confocal laser scanning microscopy (CLSM; Figure). It was found that D-g-PNIPAM+Dox nanoparticles in contrast to Dox alone showed higher toxicity towards cancer cells. This indicates a possibility of further pre-clinical studies of the water-soluble D-g-PNIPAM particles on animal tumor models in vivo as promising carriers of anticancer agents. This work was partly supported by the DFG (Germany).

Figure. CLSM images of (a) mock (untreated cells) and (b) HeLa cells after 24 h of incubation with D-g-PNIPAM+Dox. Arrows indicate the accumulation of particles inside cancer сells. Actin staining (magenta) and particles (green). Scale bar 10 μm.