TY  - JOUR
A1  - Radeloff, Katrin
A1  - Radeloff, Andreas
A1  - Ramos Tirado, Mario
A1  - Scherzad, Agmal
A1  - Hagen, Rudolf
A1  - Kleinsasser, Norbert H.
A1  - Hackenberg, Stephan
T1  - Toxicity and functional impairment in human adipose tissue-derived stromal cells (hASCs) following long-term exposure to very small iron oxide particles (VSOPs)
JF  - Nanomaterials
N2  - Magnetic nanoparticles (NPs), such as very small iron oxide NPs (VSOPs) can be used for targeted drug delivery, cancer treatment or tissue engineering. Another important field of application is the labelling of mesenchymal stem cells to allow in vivo tracking and visualization of transplanted cells using magnetic resonance imaging (MRI). For these NPs, however, various toxic effects, as well as functional impairment of the exposed cells, are described. The present study evaluates the influence of VSOPs on the multilineage differentiation ability and cytokine secretion of human adipose tissue derived stromal cells (hASCs) after long-term exposure. Human ASCs were labelled with VSOPs, and the efficacy of the labelling was documented over 4 weeks in vitro cultivation of the labelled cells. Unlabelled hASCs served as negative controls. Four weeks after labelling, adipogenic and osteogenic differentiation was histologically evaluated and quantified by polymerase chain reaction (PCR). Changes in gene expression of IL-6, IL-8, VEGF and caspase 3 were determined over 4 weeks. Four weeks after the labelling procedure, labelled and unlabelled hASCs did not differ in the gene expression of IL-6, IL-8, VEGF and caspase 3. Furthermore, the labelling procedure had no influence on the multidifferentiation ability of hASC. The percentage of labelled cells decreased during in vitro expansion over 4 weeks. Labelling with VSOPs and long-term intracellular disposition probably have no influence on the physiological functions of hASCs. This could be important for the future in vivo use of iron oxide NPs.
KW  - iron oxide nanoparticles
KW  - VSOP
KW  - nanoparticles
KW  - toxicity
KW  - differentiation potential
KW  - human adipose-derived stromal cells
KW  - stem cells
KW  - long-term exposure
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203676
SN  - 2079-4991
VL  - 10
IS  - 4
ER  - 
TY  - JOUR
A1  - Bachmann, Julia
A1  - Ehlert, Elias
A1  - Becker, Matthias
A1  - Otto, Christoph
A1  - Radeloff, Katrin
A1  - Blunk, Torsten
A1  - Bauer-Kreisel, Petra
T1  - Ischemia-like stress conditions stimulate trophic activities of adipose-derived stromal/stem cells
JF  - Cells
N2  - Adipose-derived stromal/stem cells (ASCs) have been shown to exert regenerative functions, which are mainly attributed to the secretion of trophic factors. Upon transplantation, ASCs are facing an ischemic environment characterized by oxygen and nutrient deprivation. However, current knowledge on the secretion capacity of ASCs under such conditions is limited. Thus, the present study focused on the secretory function of ASCs under glucose and oxygen deprivation as major components of ischemia. After exposure to glucose/oxygen deprivation, ASCs maintained distinct viability, but the metabolic activity was greatly reduced by glucose limitation. ASCs were able to secrete a broad panel of factors under glucose/oxygen deprivation as revealed by a cytokine antibody array. Quantification of selected factors by ELISA demonstrated that glucose deprivation in combination with hypoxia led to markedly higher secretion levels of the angiogenic and anti-apoptotic factors IL-6, VEGF, and stanniocalcin-1 as compared to the hypoxic condition alone. A conditioned medium of glucose/oxygen-deprived ASCs promoted the viability and tube formation of endothelial cells, and the proliferation and migration of fibroblasts. These findings indicate that ASCs are stimulated by ischemia-like stress conditions to secrete trophic factors and would be able to exert their beneficial function in an ischemic environment.
KW  - adipose-derived stromal/stem cells (ASCs)
KW  - regenerative medicine
KW  - secretion
KW  - trophic factors
KW  - ischemia
KW  - glucose starvation
KW  - hypoxia
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-211233
SN  - 2073-4409
VL  - 9
IS  - 9
ER  -