@article{ShityakovSalvadorPastorinetal.2015, author = {Shityakov, Sergey and Salvador, Ellaine and Pastorin, Giorgia and F{\"o}rster, Carola}, title = {Blood-brain barrier transport studies, aggregation, and molecular dynamics simulation of multiwalled carbon nanotube functionalized with fluorescein isothiocyanate}, series = {International Journal of Nanomedicine}, volume = {10}, journal = {International Journal of Nanomedicine}, doi = {10.2147/IJN.S68429}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149233}, pages = {1703-1713}, year = {2015}, abstract = {In this study, the ability of a multiwalled carbon nanotube functionalized with fluorescein isothiocyanate (MWCNT-FITC) was assessed as a prospective central nervous system-targeting drug delivery system to permeate the blood-brain barrier. The results indicated that the MWCNT-FITC conjugate is able to penetrate microvascular cerebral endothelial monolayers; its concentrations in the Transwell® system were fully equilibrated after 48 hours. Cell viability test, together with phase-contrast and fluorescence microscopies, did not detect any signs of MWCNT-FITC toxicity on the cerebral endothelial cells. These microscopic techniques also revealed presumably the intracellular localization of fluorescent MWCNT-FITCs apart from their massive nonfluorescent accumulation on the cellular surface due to nanotube lipophilic properties. In addition, the 1,000 ps molecular dynamics simulation in vacuo discovered the phenomenon of carbon nanotube aggregation driven by van der Waals forces via MWCN-TFITC rapid dissociation as an intermediate phase.}, language = {en} } @phdthesis{Seystahl2010, author = {Seystahl, Katharina Gertrud}, title = {Einfluss von Dasatinib auf die Expansion, Zytotoxizit{\"a}t und Zytokinproduktion von humanen Nat{\"u}rlichen Killer-Zellen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-51843}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2010}, abstract = {NK-Zellen spielen eine wichtige Rolle im menschlichen Immunsystem, insbesondere durch die Zerst{\"o}rung von virusinfizierten Zellen und Tumorzellen sowie durch die Produktion von Zytokinen. Eine gezielte Modulation der Effektorfunktionen von NK-Zellen kann den Weg f{\"u}r neue Therapiestrategien gegen{\"u}ber malignen Erkrankungen oder auch Autoimmunerkrankungen bahnen. Dasatinib ist ein potenter Inhibitor einer Vielzahl von Kinasen, die an der Regulation von NK-Zelleffektorfunktionen beteiligt sind und f{\"u}r die bereits eine Inhibition von T-Zelleffektorfunktionen gezeigt werden konnte [Schade et al. 2008; Weichsel et al. 2008]. Ein besseres Verst{\"a}ndnis der immunmodulatorischen Eigenschaften von Dasatinib kann nicht nur neue Einsatzbereiche identifizieren, sondern auch die bereits bew{\"a}hrte Therapie der CML optimieren. Daher wurde im Rahmen dieser Arbeit der Einfluss von Dasatinib auf die Expansion, Zytotoxizit{\"a}t und Zytokinproduktion von humanen NK-Zellen analysiert. Dazu wurden aus peripheren Blutlymphozyten gesunder Spender polyklonale NK-Zellen in Kokultur mit bestrahlten RPMI 8866-Zellen mit und ohne Dasatinib expandiert und NK-Zelleffektorfunktionen mit Durchfluszytometrie-basierten Experimenten untersucht. Im Detail wurde die Zytotoxizit{\"a}t nach dem Prinzip des FATAL-Experiments [Sheehy et al. 2001], die Degranulationsaktivit{\"a}t {\"u}ber die Expression von CD107a/b, die Produktion von TNF-α bzw. IFN-γ mit einer intrazellul{\"a}ren F{\"a}rbung und die Apoptose- und Zelltodanalyse {\"u}ber Annexin-V und 7-AAD gemessen. Die Daten dieser Arbeit zeigen, dass Dasatinib die Haupteffektorfunktionen von NK-Zellen gesunder Blutspender in vitro reguliert: Die Expansionskapazit{\"a}t von NK-Zellen wird dosisabh{\"a}ngig und bei 50 nM Dasatinib vollst{\"a}ndig inhibiert, ohne dass dies durch ein Absterben der NK-Zellen bedingt ist. Die Zytotoxizit{\"a}t von NK-Zellen, die unter 10 nM Dasatinib expandiert sind, ist nach Entfernen des Medikamentes restauriert, und die Degranulationskapazit{\"a}t und die Zytokinproduktion sind gesteigert. Bei unbehandelt expandierten NK-Zellen f{\"u}hrt die direkte Anwesenheit von Dasatinib zu einer dosisabh{\"a}ngigen Hemmung der Zytotoxizit{\"a}t gegen{\"u}ber K562-Zellen. Dar{\"u}ber hinaus inhibiert Dasatinib dosisabh{\"a}ngig die Degranulation und Zytokinproduktion von NK-Zellen bei einer Stimulation mit K562-Zellen nicht aber bei einer Stimulation mit PMA/Ca2+Ionophor. Eine indirekte Ver{\"a}nderung des Lyseverhaltens der NK-Zellen durch Effekte von Dasatinib auf die K562-Zellen zeigt sich nicht nach 4h, aber nach 24h im Sinne einer erh{\"o}hten Spontanlyse, aber geringeren spezifischen Lyse. Eine 24h-Vorbehandlung von K562-Zellen mit Dasatinib f{\"u}hrt außerdem zu einer verminderten Degranulationsaktivit{\"a}t und Zytokinproduktion von unbehandelten NK-Zellen. Die Hemmung der NK-Zelleffektorfunktionen bei direkter Anwesenheit von Dasatinib und deren Restauration respektive Steigerung nach Entfernen des Medikaments ist am ehesten auf eine reversible Inhibition von Src-Kinase-abh{\"a}ngigen Prozessen der intrazellul{\"a}ren Signal{\"u}bertragung zur{\"u}ckzuf{\"u}hren. Eine kompromittierte NK-Zellfunktion k{\"o}nnte w{\"a}hrend einer Behandlung mit Dasatinib zu einer Verminderung der Infektabwehr und der immunologischen Tumor{\"u}berwachung f{\"u}hren. M{\"o}glicherweise lassen sich jedoch die unerw{\"u}nschten Wirkungen durch ein ver{\"a}ndertes Dosisregime, wie eine Hochdosispulstherapie, bei guter Therapieeffizienz minimieren. Eine supprimierte Aktivit{\"a}t der NK-Zellen durch Dasatinib k{\"o}nnte dagegen bei der Therapie von NK-Zelllymphomen oder auch von Autoimmunerkrankungen eine neue Behandlungsoption darstellen. Aufgrund der bereits bekannten inhibitorischen Wirkung auf T-Zellfunktionen gibt es dabei m{\"o}glicherweise Synergien in der immunsuppressiven Wirkung. Das immunmodulatorische Potential von Dasatinib birgt daher große Chancen sowohl im Einsatz als Immunsuppressivum, als auch in der Optimierung der bereits bew{\"a}hrten Therapie der CML.}, subject = {Nat{\"u}rliche Killerzelle}, language = {de} } @article{RascheDuellMorgneretal.2013, author = {Rasche, Leo and Duell, Johannes and Morgner, Charlotte and Chatterjee, Manik and Hensel, Frank and Rosenwald, Andreas and Einsele, Hermann and Topp, Max S. and Br{\"a}ndlein, Stephanie}, title = {The Natural Human IgM Antibody PAT-SM6 Induces Apoptosis in Primary Human Multiple Myeloma Cells by Targeting Heat Shock Protein GRP78}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {5}, doi = {10.1371/journal.pone.0063414}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130125}, pages = {e63414}, year = {2013}, abstract = {In contrast to other haematological malignancies, targeted immunotherapy has not entered standard treatment regimens for de novo or relapsed multiple myeloma (MM) yet. While a number of IgG-formatted monoclonal antibodies are currently being evaluated in clinical trials in MM, our study aimed to investigate whether the fully human IgM monoclonal antibody PAT-SM6 that targets a tumour-specific variant of the heat shock protein GRP78 might be an attractive candidate for future immunotherapeutic approaches. We here show that GRP78 is stably and consistently expressed on the surface on tumour cells from patients with de novo, but also relapsed MM and that binding of PAT-SM6 to MM cells can specifically exert cytotoxic effects on malignant plasma cells, whereas non-malignant cells are not targeted. We demonstrate that the induction of apoptosis and, to a lesser extent, complement dependent cytotoxicity is the main mode of action of PAT-SM6, whereas antibody dependent cellular cytotoxicity does not appear to contribute to the cytotoxic properties of this antibody. Given the favourable safety profile of PAT-SM6 in monkeys, but also in a recent phase I trial in patients with malignant melanoma, our results form the basis for a planned phase I study in patients with relapsed MM.}, language = {en} } @phdthesis{Glueckermann2004, author = {Gl{\"u}ckermann, Susanne Karola}, title = {Zytotoxizit{\"a}tspr{\"u}fung verschiedener Silbertitanlegierungen auf Titanbasis mittels humaner Osteoblasten}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-11021}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2004}, abstract = {In der vorliegenden Arbeit wurde die Zytotoxizit{\"a}t verschiedener Schichten bestehend aus Silber-Titanlegierungen auf Titanbasis mittels der humanen Osteoblastenzelllinie hFOB 1.19 gepr{\"u}ft. Es sollte der Einfluß des Silberanteils in der Beschichtung auf die Zellen getestet werden. Es wurde die Wirkung auf die Proliferations- und Differenzierungsleistung der Zellen mit standardisierten Untersuchungsmethoden getestet. Des weiteren wurde die Aktivit{\"a}t der alkalischen Phosphatase und die Biomassebestimmung vorgenommen.Als Kontrolluntersuchung wurde der gleiche Versuch mit der bronchialen Epithelzelllinie HBE 16 durchgef{\"u}hrt. Die Zellkultivierung erfolgte {\"u}ber einen 14-t{\"a}gigen Zeitraum. Als Referenzoberfl{\"a}che wurde konventionelles Zellkultur-Polystyrol verwendet. Die Zellvitalit{\"a}t wurde mit Hilfe des WST-1-Tests, der Differenzierungstatus anhand der Aktivit{\"a}t der alkalischen Phosphatase und der Proteingehalt mittels der Proteinbestimmung nach Bradford erfaßt. Es zeigten sich bei allen Messungen starke Schwankungen der Zellzahl, Zellvitalit{\"a}t, der spezifischen Aktivit{\"a}t der alkalischen Phosphatase und des Proteingehalts auf den Oberfl{\"a}chen. Eine Proportionalit{\"a}t zwischen den verschiedenen Silberkonzentrationen und den Proliferationszahlen war nicht zu beobachten. Mit dem Wissen {\"u}ber die hervorragende Biokompatibilit{\"a}t von Titan und der nachgewiesenen bakteriostatischen Wirkung von Silber ist dies ein hervorragender Werkstoff , welcher sch{\"a}dliche Bakterien um das Implantat herum eliminiert und trotzdem ein ungehindertes Einwachsen des Implantats in den Knochen erlaubt.}, language = {de} } @article{GordonDaneshianBouwstraetal.2015, author = {Gordon, Sarah and Daneshian, Mardas and Bouwstra, Joke and Caloni, Francesca and Constant, Samuel and Davies, Donna E. and Dandekar, Gudrun and Guzman, Carlos A. and Fabian, Eric and Haltner, Eleonore and Hartung, Thomas and Hasiwa, Nina and Hayden, Patrick and Kandarova, Helena and Khare, Sangeeta and Krug, Harald F. and Kneuer, Carsten and Leist, Marcel and Lian, Guoping and Marx, Uwe and Metzger, Marco and Ott, Katharina and Prieto, Pilar and Roberts, Michael S. and Roggen, Erwin L. and Tralau, Tewes and van den Braak, Claudia and Walles, Heike and Lehr, Claus-Michael}, title = {Non-animal models of epithelial barriers (skin, intestine and lung) in research, industrial applications and regulatory toxicology}, series = {ALTEX: Alternatives to Animal Experimentation}, volume = {32}, journal = {ALTEX: Alternatives to Animal Experimentation}, number = {4}, doi = {10.14573/altex.1510051}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144275}, pages = {327-378}, year = {2015}, abstract = {Models of the outer epithelia of the human body namely the skin, the intestine and the lung have found valid applications in both research and industrial settings as attractive alternatives to animal testing. A variety of approaches to model these barriers are currently employed in such fields, ranging from the utilization of ex vivo tissue to reconstructed in vitro models, and further to chip-based technologies, synthetic membrane systems and, of increasing current interest, in silico modeling approaches. An international group of experts in the field of epithelial barriers was convened from academia, industry and regulatory bodies to present both the current state of the art of non-animal models of the skin, intestinal and pulmonary barriers in their various fields of application, and to discuss research-based, industry-driven and regulatory-relevant future directions for both the development of new models and the refinement of existing test methods. Issues of model relevance and preference, validation and standardization, acceptance, and the need for simplicity versus complexity were focal themes of the discussions. The outcomes of workshop presentations and discussions, in relation to both current status and future directions in the utilization and development of epithelial barrier models, are presented by the attending experts in the current report.}, language = {en} } @article{ScherzadMeyerIckrathetal.2019, author = {Scherzad, Agmal and Meyer, Till and Ickrath, Pascal and Gehrke, Thomas Eckhart and Bregenzer, Maximillian and Hagen, Rudolf and Dembski, Sofia and Hackenberg, Stephan}, title = {Cultivation of hMSCs in human plasma prevents the cytotoxic and genotoxic potential of ZnO-NP in vitro}, series = {Applied Sciences}, volume = {9}, journal = {Applied Sciences}, number = {23}, issn = {2076-3417}, doi = {10.3390/app9234994}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193063}, year = {2019}, abstract = {Zinc oxide nanoparticles (ZnO-NPs) are commonly used for industrial applications. Consequently, there is increasing exposure of humans to them. The in vitro analysis of cytotoxicity and genotoxicity is commonly performed under standard cell culture conditions. Thus, the question arises of how the results of genotoxicity and cytotoxicity experiments would alter if human plasma was used instead of cell culture medium containing of fetal calf serum (FCS). Human mesenchymal stem cells (hMSCs) were cultured in human plasma and exposed to ZnO-NPs. A cultivation in expansion medium made of DMEM consisting 10\% FCS (DMEM-EM) served as control. Genotoxic and cytotoxic effects were evaluated with the comet and MTT assay, respectively. hMSC differentiation capacity and ZnO-NP disposition were evaluated by histology and transmission electron microscopy (TEM). The protein concentration and the amount of soluble Zn2+ were measured. The cultivation of hMSCs in plasma leads to an attenuation of genotoxic and cytotoxic effects of ZnO-NPs compared to control. The differentiation capacity of hMSCs was not altered. The TEM showed ZnO-NP persistence in cytoplasm in both groups. The concentrations of protein and Zn2+ were higher in plasma than in DMEM-EM. In conclusion, the cultivation of hMSCs in plasma compared to DMEM-EM leads to an attenuation of cytotoxicity and genotoxicity in vitro.}, language = {en} } @article{IckrathWagnerScherzadetal.2017, author = {Ickrath, Pascal and Wagner, Martin and Scherzad, Agmal and Gehrke, Thomas and Burghartz, Marc and Hagen, Rudolf and Radeloff, Katrin and Kleinsasser, Norbert and Hackenberg, Stephan}, title = {Time-Dependent Toxic and Genotoxic Effects of Zinc Oxide Nanoparticles after Long-Term and Repetitive Exposure to Human Mesenchymal Stem Cells}, series = {International Journal of Environmental Research and Public Health}, volume = {14}, journal = {International Journal of Environmental Research and Public Health}, number = {12}, doi = {10.3390/ijerph14121590}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169932}, pages = {1590}, year = {2017}, abstract = {Zinc oxide nanoparticles (ZnO-NP) are widely spread in consumer products. Data about the toxicological characteristics of ZnO-NP is still under controversial discussion. The human skin is the most important organ concerning ZnO-NP exposure. Intact skin was demonstrated to be a sufficient barrier against NPs; however, defect skin may allow NP contact to proliferating cells. Within these cells, stem cells are the most important toxicological target for NPs. The aim of this study was to evaluate the genotoxic and cytotoxic effects of ZnO-NP at low-dose concentrations after long-term and repetitive exposure to human mesenchymal stem cells (hMSC). Cytotoxic effects of ZnO-NP were measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Furthermore, genotoxicity was evaluated by the comet assay. For long-term observation over 6 weeks, transmission electron microscopy (TEM) was applied. The results of the study indicated cytotoxic effects of ZnO-NP beginning at high concentrations of 50 μg/mL and genotoxic effects in hMSC exposed to 1 and 10 μg/mL ZnO-NP. Repetitive exposure enhanced cyto- but not genotoxicity. Intracellular NP accumulation was observed up to 6 weeks. The results suggest cytotoxic and genotoxic potential of ZnO-NP. Even low doses of ZnO-NP may induce toxic effects as a result of repetitive exposure and long-term cellular accumulation. This data should be considered before using ZnO-NP on damaged skin.}, language = {en} } @article{AbdElAzizElMaghrabyEwaldetal.2021, author = {Abd El-Aziz, Asmaa M. and El-Maghraby, Azza and Ewald, Andrea and Kandil, Sherif H.}, title = {In-vitro cytotoxicity study: cell viability and cell morphology of carbon nanofibrous scaffold/hydroxyapatite nanocomposites}, series = {Molecules}, volume = {26}, journal = {Molecules}, number = {6}, issn = {1420-3049}, doi = {10.3390/molecules26061552}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234037}, year = {2021}, abstract = {Electrospun carbon nanofibers (CNFs), which were modified with hydroxyapatite, were fabricated to be used as a substrate for bone cell proliferation. The CNFs were derived from electrospun polyacrylonitrile (PAN) nanofibers after two steps of heat treatment: stabilization and carbonization. Carbon nanofibrous (CNF)/hydroxyapatite (HA) nanocomposites were prepared by two different methods; one of them being modification during electrospinning (CNF-8HA) and the second method being hydrothermal modification after carbonization (CNF-8HA; hydrothermally) to be used as a platform for bone tissue engineering. The biological investigations were performed using in-vitro cell counting, WST cell viability and cell morphology after three and seven days. L929 mouse fibroblasts were found to be more viable on the hydrothermally-modified CNF scaffolds than on the unmodified CNF scaffolds. The biological characterizations of the synthesized CNF/HA nanofibrous composites indicated higher capability of bone regeneration.}, language = {en} } @article{WilhelmsBroscheitShityakov2023, author = {Wilhelms, Benedikt and Broscheit, Jens and Shityakov, Sergey}, title = {Chemical analysis and molecular modelling of cyclodextrin-formulated propofol and its sodium salt to improve drug solubility, stability and pharmacokinetics (cytogenotoxicity)}, series = {Pharmaceuticals}, volume = {16}, journal = {Pharmaceuticals}, number = {5}, issn = {1424-8247}, doi = {10.3390/ph16050667}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313705}, year = {2023}, abstract = {Propofol is a widely used general anesthetic in clinical practice, but its use is limited by its water-insoluble nature and associated pharmacokinetic and pharmacodynamic limitations. Therefore, researchers have been searching for alternative formulations to lipid emulsion to address the remaining side effects. In this study, novel formulations for propofol and its sodium salt Na-propofolat were designed and tested using the amphiphilic cyclodextrin (CD) derivative hydroxypropyl-β-cyclodextrin (HPβCD). The study found that spectroscopic and calorimetric measurements suggested complex formation between propofol/Na-propofolate and HPβCD, which was confirmed by the absence of an evaporation peak and different glass transition temperatures. Moreover, the formulated compounds showed no cytotoxicity and genotoxicity compared to the reference. The molecular modeling simulations based on molecular docking predicted a higher affinity for propofol/HPβCD than for Na-propofolate/HPβCD, as the former complex was more stable. This finding was further confirmed by high-performance liquid chromatography. In conclusion, the CD-based formulations of propofol and its sodium salt may be a promising option and a plausible alternative to conventional lipid emulsions.}, language = {en} }