TY - JOUR A1 - Kaufner, L. A1 - Cartier, R. A1 - Wüstneck, R. A1 - Fichtner, I. A1 - Pietschmann, S. A1 - Bruhn, H. A1 - Schütt, Dagmar A1 - Thünemann, Andreas A1 - Pison, U. T1 - Poly(ethylene oxide)-block-poly(glutamic acid) coated maghemite nanoparticles: in vitro characterization and in vivo behaviour N2 - Positively charged superparamagnetic iron oxide (SPIO) particles of maghemite were prepared in aqueous solution and subsequently stabilized with poly(ethylene oxide)-block-poly(glutamic acid) (PEO–PGA) at a hydrodynamic diameter of 60 nm. Depending on the amount of PEO–PGA used, this is accompanied by a switching of their zeta potentials from positive to negative charge (-33 mV). As a prerequisite for in vivo testing, the PEO–PGA coated maghemite nanoparticles were evaluated to be colloidally stable in water and in physiological salt solution for longer than six months as well in various buffer systems under physiological pH and salt conditions (AFM, dynamic light scattering). We excluded toxic effects of the PEO–PGA coated maghemite nanoparticles. We demonstrated by in vivo MR-imaging and 111In measurements a biodistribution of the nanoparticles into the liver comparable to carboxydextran coated superparamagnetic iron oxide nanoparticles (Resovist®) as a reference nanoscaled MRI contrast medium. This was enforced by a detailed visualization of our nanoparticles by electron microscopy of liver tissue sections. Furthermore, our results indicate that 15% of the injected PEO–PGA coated maghemite nanoparticles circulate in the blood compartment for at least 60 min after i.v. application. KW - Nanotechnology KW - Nano Particle KW - Block-Copolymer PY - 2007 U6 - https://doi.org/10.1088/0957-4484/18/11/115710 SN - 0957-4484 SN - 1361-6528 VL - 18 IS - 11 SP - 115710 (1 EP - 10) PB - IOP Publishing Ltd. CY - Bristol AN - OPUS4-16494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schallschmidt, Kristin A1 - Becker, Roland A1 - Jung, Christian A1 - Rolff, J. A1 - Fichtner, I. T1 - Investigation of cell culture volatilomes using solid phase micro extraction: options and pitfalls exemplified with adenocarcinoma cell lines N2 - Three strategies to sample volatile organic compounds (VOC) from lung cancer cell lines cultured in vitro were compared. Headspace solid phase microextraction was applied in situ to culture flasks and alternatively to subsamples of headspace gas or to nutrient solution subsamples followed by gas chromatography–mass spectrometry. The direct quantification of 55 VOC in the headspace of cell cultures was validated and is discussed with respect to reproducibility and system-related interferences. The role of the VOC background from culture media and usually employed polystyrene culture vessels is examined and was seen to invoke potentially misleading conclusions. The commercial A549 and two further adenocarcinoma cell lines displayed largely similar VOC profiles with distinct differences regarding certain individual substances. There is evidence for the inappropriateness of the standard cell culturing methods in the search for volatile cancer markers. KW - A549 KW - Lung cancer cell culture KW - GC–MS KW - SPME KW - VOC KW - Volatilome KW - Alcohol marker KW - Micropulverization KW - HPLC-MS/MS KW - Fortification KW - Long term stability PY - 2015 U6 - https://doi.org/10.1016/j.jchromb.2015.10.004 SN - 0378-4347 SN - 1570-0232 SN - 1387-2273 SN - 1873-376X VL - 1006 SP - 158 EP - 166 PB - Elsevier B.V. CY - Amsterdam [u.a.] AN - OPUS4-34991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -