A NOVEL PERFUSION BIOREACTOR FOR 3D CELL CULTURE IN MICROGRAVITY CONDITIONS

摘要

Cell suspension culture methods based on the generation of microgravity environment are widely used in regenerative medicine for (1) the production of native-like three-dimensional (3D) cell aggregates and engineered tissues [1,2,3], for (2) low cost scalable cell expansion and long-term cell viability maintenance [4,5], and for (3) guiding differentiation of stem cells (SCs) [6]. The generation of a microgravity environment for 3D cell cultures, mimicking the native environment, promotes spatial freedom, cell growth, cell-cell interaction and improves mass transfer and cell exposure to nutrients. Nowadays, microgravity cell cultures are obtained by using stirred or rotating bioreactors, but both devices suffer from limitations: stirring bioreactors generate non-physiological shear stresses, which could damage cultured cells, interfere with SC pluripotency, and limit reproducibility of the culture process; rotating bioreactors are expensive devices due to the complex technological solutions adopted for obtaining rotation [5]. Here, we present a novel low-cost dynamic culture device (DCD) which, taking advantage of the driven-by-shape hydrodynamics established within the culture chamber, allows to culture specimens in microgravity low-shear conditions, without resorting to rotating systems. Both the DCD design and optimization phases were supported by computational multiphysics modeling, which allowed to identify (1) the optimal geometry for the culture chamber, and (2) the proper operating conditions for cell culturing. According to in silico results, factory tests, performed using hydrogel microspheres as suspended specimens, demonstrated the effectiveness of the chamber geometry in obtaining microgravity conditions. Moreover, preliminary short term cellular tests demonstrated the performances of the DCD in assuring sterility and cell viability maintenance.