Induction of endochondral ossification by acellular generated ROS using a hydrostatic pressure bioreactor systeme

Hypothesis/Aim: The aim of this study is to induce and enhance endochondral ossification (EO) of mesenchymal stem cells in pellet cultures or seeded on silk-based sponges via elevated levels of reactive oxygen species (ROS) generated via a custom-made hydrostatic pressure (HP) bioreactor system. Our hypothesis is that by defining acellular generated ROS levels we can induce/enhance hypertrophy in cell cultures by leading to mineralization and bone-like tissue formation. In this regard, ROS are mainly associated with cellular damage but their physiological role including chondrocyte hypertrophy in EC is well accepted [1-3]. In this topic a HP bioreactor system of the UASTW will be used that is capable of stimulating cell cultures with elevated ROS-levels [4]. Dose-finding of ROS (timing and levels) will be crucial to identify optimal ROS levels that modulate the initiation of the hypertrophic changes. To follow cellular changes an integrated approach including gene expression, western blot, IF-stainings, histology as well as proteomics will be chosen. Of special interest will be the investigation of the tissue maturation process using molecular imaging (matrix-assisted laser desorption/ionisation mass spectrometric imaging (MALDI MSI)) in combination with elemental imaging (laser ablation inductively couple plasma mass spectrometry (LAICP MSI) and/or micro x-ray fluorescence (µXRF)).

References: [1] Morita et al. J. Exp. Med. 204, 1613–23 (2007). [2] Kronenberg, H. M. Nature 423, 332–6 (2003). [3] Kim et al. J. Biol. Chem. 285, 40294–302 (2010). [4] Rieder et al. Sci. Rep. 8, 17010 (2018). [5] J Intern Med. 2015 Jun;277(6):681-9.