@article{RamirezRodriguezPereiraHerrmannetal.2021, author = {Ram{\´i}rez-Rodr{\´i}guez, Gloria Bel{\´e}n and Pereira, Ana Rita and Herrmann, Marietta and Hansmann, Jan and Delgado-L{\´o}pez, Jos{\´e} Manuel and Sprio, Simone and Tampieri, Anna and Sandri, Monica}, title = {Biomimetic mineralization promotes viability and differentiation of human mesenchymal stem cells in a perfusion bioreactor}, series = {International Journal of Molecular Sciences}, volume = {22}, journal = {International Journal of Molecular Sciences}, number = {3}, issn = {1422-0067}, doi = {10.3390/ijms22031447}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285804}, year = {2021}, abstract = {In bone tissue engineering, the design of 3D systems capable of recreating composition, architecture and micromechanical environment of the native extracellular matrix (ECM) is still a challenge. While perfusion bioreactors have been proposed as potential tool to apply biomechanical stimuli, its use has been limited to a low number of biomaterials. In this work, we propose the culture of human mesenchymal stem cells (hMSC) in biomimetic mineralized recombinant collagen scaffolds with a perfusion bioreactor to simultaneously provide biochemical and biophysical cues guiding stem cell fate. The scaffolds were fabricated by mineralization of recombinant collagen in the presence of magnesium (RCP.MgAp). The organic matrix was homogeneously mineralized with apatite nanocrystals, similar in composition to those found in bone. X-Ray microtomography images revealed isotropic porous structure with optimum porosity for cell ingrowth. In fact, an optimal cell repopulation through the entire scaffolds was obtained after 1 day of dynamic seeding in the bioreactor. Remarkably, RCP.MgAp scaffolds exhibited higher cell viability and a clear trend of up-regulation of osteogenic genes than control (non-mineralized) scaffolds. Results demonstrate the potential of the combination of biomimetic mineralization of recombinant collagen in presence of magnesium and dynamic culture of hMSC as a promising strategy to closely mimic bone ECM.}, language = {en} } @article{KunzeLillaStetteretal.2018, author = {Kunze, Ekkehard and Lilla, Nadine and Stetter, Christian and Ernestus, Ralf-Ingo and Westermaier, Thomas}, title = {Magnesium protects in episodes of critical perfusion after aneurysmal SAH}, series = {Translational Neuroscience}, volume = {9}, journal = {Translational Neuroscience}, number = {1}, doi = {10.1515/tnsci-2018-0016}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177078}, pages = {99-105}, year = {2018}, abstract = {Background: To analyze whether magnesium has a neuroprotective effect during episodes that indicate a critical brain perfusion after aneurysmal subarachnoid hemorrhage (SAH). Methods: 107 patients with aSAH were randomized to continuously receive intravenous magnesium sulfate with target serum levels of 2.0 - 2.5 mmol/l (n = 54) or isotonic saline (n = 53). Neurological examination and transcranial Doppler sonography (TCD) were performed daily, Perfusion-CT (PCT) was acquired in 3-day intervals, angiography in case of suspected vasospasm. The primary endpoint was the development of secondary infarction following episodes of delayed ischemic neurological deficit (DIND), elevated mean flow velocity (MFV) in TCD or pathological findings in PCT. Results: In the magnesium group, 9 episodes of DIND were registered, none was followed by secondary infarction. In the control group, 23 episodes of DIND were registered, 9 were followed by secondary infarction (p < 0.05). In the magnesium group, 114 TCD-measurements showed an elevated MFV(> 140 cm/s). 7 were followed by new infarction. In control patients, 135 measurements showed elevated MFV, 32 were followed by new infarction (p < 0.05). 10 of 117 abnormal PCT-findings were followed by new infarction, compared to 30 of 122 in the control-group (p < 0.05). Conclusion: DIND, elevated MFV in TCD and abnormal PCT are findings which are associated with an increased risk to develop delayed secondary infarction. The results of this analysis suggest that magnesium-treatment may reduce the risk to develop infarction in a state of critical brain perfusion.}, language = {en} }