GROWTH BEHAVIOR OF HUMAN ADIPOSE TISSUE-DERIVED STROMAL/STEM CELLS IN SINGLE-USE SPINNER FLASKS: NUMERICAL AND EXPERIMENTAL INVESTIGATIONS

摘要

Human adipose tissue-derived stromal/stem cells (hASC) represent a valuable source of cells for clinical applications, especially in the field of regenerative medicine. Therefore, it comes as no surprise that interest in hASCs has increased greatly over the last decade. However, in order to use hASCs successfully in clinical applications, in vitro expansion is required. Single-use bioreactors in combination with microcarriers (MC) have been shown to be suitable systems for this task (1-3). However, hASCs are prone to higher shear sensitivity than conventional cell lines (e.g. CHO, BHK) that are normally expanded in these systems. Hence, the goal of this study was to investigate the influence of different shear stress levels on the growth of hASCs in small scale single-use spinner flasks. For this purpose, Computational Fluid Dynamics simulations based on a Euler-Euler and Euler-Lagrange approach were performed to predict the hydrodynamic stresses (0.06 - 0.87 Pa), the residence times (0.4-7.3 s) and the circulation times (1.6 - 16.6 s) of the MCs in various high shear zones. The numerical findings were combined with experimental data from cultivation studies (0.29 - 1.1·10~6 hASC/mL) in order to develop a segregated mathematical growth model for the prediction of MC-associated hASC growth in small scale single-use spinner flasks.