Dresden 2009 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 39: POSTERS Colloids and Liquids

CPP 39.17: Poster

Thursday, March 26, 2009, 17:00–19:30, P3

Synthesis, characterization and cellular uptake of aminofunctionalized fluoresceine-labeled silica nanospheres — •Qi Gao¹, Christina Graf¹, Cynthia Kembuan¹, Fiorenza Rancan², Stefen Troppens², Sabrina Hadam², Annika Vogt², and Eckart Rühl¹ — ¹Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin — ²Department of Dermatology and Allergy, Charité- Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin

The understanding of the uptake mechanism of silica nanoparticles (NPs) by human cells is important for the development of NPs as novel therapeutic and diagnostic agents. Luminescent silica NPs are promising labeling reagents for various biomedical applications. We investigated the biological properties of 3-aminopropyltrimethysilane (APS) functionalized and fluoresceine (FITC) labeled silica nanospheres. Nearly monodisperse FITC dye-labeled silica nanospheres with diameters of 30 - 300 nm are prepared by several modifications of the Stöber process. Surface functionalization by APS allows us to adjust the zeta potential of these nanospheres from highly negative to positive (-55 mV to +45 mV). Size and zeta potential of the NPs were characterized by transmission electron microscopy and dynamic light scattering. A positive zeta potential enhances the interaction of the nanoparticles with the negatively charged cell surface and hence, the cellular uptake. Toxicity experiments indicate that these FITC dye-labeled silica NPs are not toxic to human cells. Research on the uptake of the NPs to cells, especially human skin cells, is currently in progress.