The effective drug delivery systems for cancer treatment are currently on high demand. In this paper, biological behavior of the novel hybrid copolymers based on polysaccharide glycogen were characterized. The copolymers were modified by fluorescent dyes for flow cytometry, confocal microscopy, and in vivo fluorescence imaging. Moreover, the effect of oxazoline grafts on degradation rate was examined. Intracellular localization, cytotoxicity, and internalization route of the modified copolymers were examined on HepG2 cell line. Biodistribution of copolymers was addressed by in vivo fluorescence imaging in C57BL/6 mice. Our results indicate biocompatibility, biodegradability, and non-toxicity of the glycogen-based hybrid copolymers. Copolymers were endocyted into the cytoplasm, most probably via caveolae-mediated endocytosis. Higher content of oxazoline in polymers slowed down cellular uptake. No strong colocalization of the glycogen-based probe with lysosomes was observed; thus, it seems that the modified externally administered glycogen is degraded in the same way as an endogenous glycogen. In vivo experiment showed relatively fast biodistribution and biodegradation. In conclusion, this novel nanoprobe offers unique chemical and biological attributes for its use as a novel drug delivery system that might serve as an efficient carrier for cancer therapeutics with multimodal imaging properties.

Department of Physiology Faculty of Science Charles University Prague Viničná 7 128 44 Praha 2 Czech Republic

Institute for Clinical and Experimental Medicine Videnska 1958 9 140 21 Prague 4 Czech Republic

Institute of Biophysics and Informatics 1st Medicine Faculty Charles University Salmovská 1 12000 Prague 2 Czech Republic

Institute of Macromolecular Chemistry of the Academy of Sciences of the Czech Republic Heyrovsky Sq 2 162 06 Prague 6 Czech Republic

Institute of Physiology of the Academy of Sciences of the Czech Republic Videnska 1083 142 20 Prague 4 Czech Republic

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