TY - GEN A1 - Steinbrecht, Susanne A1 - Pfeifer, Nadine A1 - Herzog, Natalie A1 - Katzenberger, Nadine A1 - Schulz, Christian A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner T1 - HepG2-1A2 C2 and C7: Lentivirus vector-mediated stable and functional overexpression of cytochrome P450 1A2 in human hepatoblastoma cells T2 - Toxicology Letters N2 - Novel HepG2 cell clones 1A2 C2 and 1A2 C7 were independently generated by lentiviral transduction to functionally overexpress cytochrome P450 1A2 (CYP1A2). We found similar and stable CYP1A2 transcript and protein levels in both cell clones leading to specific enzyme activities of about 370 pmol paracetamol x min-1 x mg-1 protein analyzed by phenacetin conversion. Both clones showed dramatically increased sensitivity to the hepatotoxic compound aflatoxin B1 (EC50<100 nM) when compared to parental HepG2 cells (EC50 ∼5 μM). Thus, newly established cell lines are an appropriate tool to study metabolism and toxicity of substances depending on conversion by CYP1A2. KW - HepG2 KW - CYP1A2 KW - Cytochrome P450 KW - Liver metabolism Y1 - 2020 U6 - https://doi.org/10.1016/j.toxlet.2019.11.006 SN - 0378-4274 VL - 319 SP - 155 EP - 159 ER - TY - GEN A1 - Jurischka, Christoph A1 - Dinter, Franziska A1 - Efimova, Anastasia A1 - Weiss, Romano A1 - Schiebel, Juliane A1 - Schulz, Christian A1 - Fayziev, Bekzodjon A1 - Schierack, Peter A1 - Fischer, Thomas A1 - Rödiger, Stefan T1 - An explorative study of polymers for 3D printing of bioanalytical test systems T2 - Clinical Hemorheology and Microcirculation N2 - Background: The 3D printing is relevant as a manufacturing technology of functional models for forensic, pharmaceutical and bioanalytical applications such as drug delivery systems, sample preparation and point-of-care tests. Objective: Melting behavior and autofluorescence of materials are decisive for optimal printing and applicability of the product which are influenced by varying unknown additives. Methods: We have produced devices for bioanalytical applications from commercially available thermoplastic polymers using a melt-layer process. We characterized them by differential scanning calorimetry, fluorescence spectroscopy and functional assays (DNA capture assay, model for cell adhesion, bacterial adhesion and biofilm formation test). Results: From 14 tested colored, transparent and black materials we found only deep black acrylonitrile-butadiene-styrene (ABS) and some black polylactic acid (PLA) useable for fluorescence-based assays, with low autofluorescence only in the short-wave range of 300-400 nm. PLA was suitable for standard bioanalytical purposes due to a glass transition temperature of approximately 60°C, resistance to common laboratory chemicals and easy print processing. For temperature-critical methods, such as hybridization reactions up to 90°C, ABS was better suited. Conclusions: Autofluorescence was not a disadvantage per se but can also be used as a reference signal in assays. The rapid development of individual protocols for sample processing and analysis required the availability of a material with consistent quality over time. For fluorescence-based assays, the use of commercial standard materials did not seem to meet this requirement. KW - Thermal analysis KW - 3D Printing Y1 - 2020 UR - https://pubmed.ncbi.nlm.nih.gov/31929149/ U6 - https://doi.org/10.3233/CH-190713 SN - 1875-8622 VL - 75 IS - 1 SP - 57 EP - 84 ER - TY - GEN A1 - Schulz, Christian A1 - Krüger-Genge, Anne A1 - Jung, Friedrich A1 - Lendlein, Andreas T1 - Aptamer supported in vitro endothelialization of poly(ether imide) films T2 - Clinical Hemorheology and Microcirculation N2 - Implantation of synthetic small-diameter vascular bypass grafts is often associated with an increased risk of failure, due to thrombotic events or late intimal hyperplasia. As one of the causes an insufficient hemocompatibility of the artificial surface is discussed. Endothelialization of synthetic grafts is reported to be a promising strategy for creating a self-renewing and regulative anti-thrombotic graft surface. However, the establishment of a shear resistant cell monolayer is still challenging. In our study, cyto- and immuno-compatible poly(ether imide) (PEI) films were explored as potential biomaterial for cardiovascular applications. Recently, we reported that the initial adherence of primary human umbilical vein endothelial cells (HUVEC) was delayed on PEI-films and about 9 days were needed to establish a confluent and almost shear resistant HUVEC monolayer. To accelerate the initial adherence of HUVEC, the PEI-film surface was functionalized with an aptamer-cRGD peptide based endothelialization supporting system. With this functionalization the initial adherence as well as the shear resistance of HUVEC on PEI-films was considerable improved compared to the unmodified polymer surface. The in vitro results confirm the general applicability of aptamers for an efficient functionalization of substrate surfaces. KW - aptamer KW - endothelialization KW - physical functionalization KW - poly(ether imide) films KW - shear resistance Y1 - 2020 U6 - https://doi.org/10.3233/CH-190775 SN - 1875-8622 SN - 1386-0291 VL - 75 IS - 2 SP - 201 EP - 217 ER - TY - GEN A1 - Prill, Robert A1 - Singh, Jasvinder A. A1 - Seeber, Gesine H. A1 - Mai Nielsen, Sabrina A1 - Goodman, Susan A1 - Michel, Sven A1 - Kopkow, Christian A1 - Schulz, Robert A1 - Choong, Peter A1 - Hommel, Hagen T1 - Patient, physiotherapist and surgeon endorsement of the core domain set for total hip and total knee replacement in Germany: a study protocol for an OMERACT initiative T2 - BMJ open Y1 - 2020 U6 - https://doi.org/10.1136/bmjopen-2019-035207 SN - 2044-6055 VL - 10 IS - 6 ER -