- Email: [email protected]
INNOVATIVE MICROGRAVITY PERFUSION BIOREACTOR FOR HYDROGEL-BASED REGENERATIVE MEDICINE
Presentation 1689 − Topic 43. Tissue engineering
S659
INNOVATIVE MICROGRAVITY PERFUSION BIOREACTOR FOR HYDROGEL-BASED REGENERATIVE MEDICINE Giulia Cerino (1), Diana Massai (1), Davide Lorusso (1), Diego Gallo (1), Francesco Pennella (1), Marco A. Deriu (1), Constantin Ciobanu (2), Franco M. Montevecchi (1), Umberto Morbiducci (1)
1. Politecnico di Torino, Italy; 2. Petru Poni Institute Macromol. Chem., Romania
Objectives In regenerative medicine, hydrogel-based injectable scaffolds are becoming a promising strategy for supporting the regeneration of injured tissues [Li, 2011]. The rationale for this study was to design an innovative low-cost perfusion bioreactor dedicated to provide a suitable biochemical and hydrodynamic environment for testing viability, growth and differentiation of cells cultured on hydrogel microspheres in microgravity condition. Microgravity condition is obtained by establishing a mixing slow vortex that allows adequate microsphere suspension and oxygen transport, without using rotating components. Computational simulations were performed for assisting the bioreactor design, for studying the hydrogelmedium interactions, and for identifying the operating conditions that optimize mass transport.
(flow rate range = 20-30 ml/min). In accordance with the computational results, experimental tests demonstrated the suitability of the bioreactor geometry: the proper combination of the fluid dynamic conditions establishing within the chamber, and the shape of the side walls of the chamber give rise to flow separation, with the consequent formation of stationary buoyant vortices and of hydrodynamic forces (Fig. 1b). The balance between hydrodynamic and gravitational forces allows (1) to maintain microspheres in homogeneous suspension conditions, (2) to guarantee suitable mass transfer and oxygen transport, and (3) to avoid both the sedimentation of microspheres at the bottom of the chamber, and their crushing on the filter.
Materials and Methods The geometric features of the bioreactor allow the formation of buoyant vortices within the culture chamber: the culture medium enters from the base, moves through the check valve (AISI 316L), pervades the culture chamber (polycarbonate), and flows out from the top (Fig. 1a). Within the culture chamber are located a filter, designed in order to prevent accidental outputs of microspheres during the recirculation of the culture medium, and a check valve, with a holed silicone membrane that moves according to the pressure gradients, for guarantying the unidirectionality of the flow. Multiphase axial symmetric computational simulations were performed, by adopting a finite volume method (Fluent 6.3.26, ANSYS Inc.), and setting the physical properties of culture medium (density=1006.5 kg/m3, viscosity = 0.001 kg/(m·s)) and polyurethane hydrogel microspheres (diameter = 500 μm, density = 1118 kg/m3). Preliminary operating tests were conducted using distilled water as culture medium, and hydrogel microspheres. Perfusion was regulated by a peristaltic pump.
Figure 1: (a) Hydrogel microspheres within the bioreactor (95x70x70 mm3; priming volume = 50 ml); (b) Colour maps of culture medium vorticity magnitude values. Moreover, computational simulations allowed to verify that the generated microgravity condition [Gerecht-Nir, 2004] avoids shear stress values critical for the cells (maximum shear stress = 0.4 Pa). In the near future, experimental tests with hydrogel microspheres seedeed with cardiac cells will be performed. The present work is carried out in the scope of BIOSCENT European Project (ID 214539).
Results and Discussions Findings from computational simulations allowed to optimize the bioreactor geometry, and to identify the operating conditions for the preliminary tests
References Li Z. et al, Polymers, 3:740-761, 2011.Gerecht-Nir S. et al, Biotechnol Bioeng, 86(5):493-502, 2004.
ESB2012: 18th Congress of the European Society of Biomechanics
Journal of Biomechanics 45(S1)
S659
INNOVATIVE MICROGRAVITY PERFUSION BIOREACTOR FOR HYDROGEL-BASED REGENERATIVE MEDICINE Giulia Cerino (1), Diana Massai (1), Davide Lorusso (1), Diego Gallo (1), Francesco Pennella (1), Marco A. Deriu (1), Constantin Ciobanu (2), Franco M. Montevecchi (1), Umberto Morbiducci (1)
1. Politecnico di Torino, Italy; 2. Petru Poni Institute Macromol. Chem., Romania
Objectives In regenerative medicine, hydrogel-based injectable scaffolds are becoming a promising strategy for supporting the regeneration of injured tissues [Li, 2011]. The rationale for this study was to design an innovative low-cost perfusion bioreactor dedicated to provide a suitable biochemical and hydrodynamic environment for testing viability, growth and differentiation of cells cultured on hydrogel microspheres in microgravity condition. Microgravity condition is obtained by establishing a mixing slow vortex that allows adequate microsphere suspension and oxygen transport, without using rotating components. Computational simulations were performed for assisting the bioreactor design, for studying the hydrogelmedium interactions, and for identifying the operating conditions that optimize mass transport.
(flow rate range = 20-30 ml/min). In accordance with the computational results, experimental tests demonstrated the suitability of the bioreactor geometry: the proper combination of the fluid dynamic conditions establishing within the chamber, and the shape of the side walls of the chamber give rise to flow separation, with the consequent formation of stationary buoyant vortices and of hydrodynamic forces (Fig. 1b). The balance between hydrodynamic and gravitational forces allows (1) to maintain microspheres in homogeneous suspension conditions, (2) to guarantee suitable mass transfer and oxygen transport, and (3) to avoid both the sedimentation of microspheres at the bottom of the chamber, and their crushing on the filter.
Materials and Methods The geometric features of the bioreactor allow the formation of buoyant vortices within the culture chamber: the culture medium enters from the base, moves through the check valve (AISI 316L), pervades the culture chamber (polycarbonate), and flows out from the top (Fig. 1a). Within the culture chamber are located a filter, designed in order to prevent accidental outputs of microspheres during the recirculation of the culture medium, and a check valve, with a holed silicone membrane that moves according to the pressure gradients, for guarantying the unidirectionality of the flow. Multiphase axial symmetric computational simulations were performed, by adopting a finite volume method (Fluent 6.3.26, ANSYS Inc.), and setting the physical properties of culture medium (density=1006.5 kg/m3, viscosity = 0.001 kg/(m·s)) and polyurethane hydrogel microspheres (diameter = 500 μm, density = 1118 kg/m3). Preliminary operating tests were conducted using distilled water as culture medium, and hydrogel microspheres. Perfusion was regulated by a peristaltic pump.
Figure 1: (a) Hydrogel microspheres within the bioreactor (95x70x70 mm3; priming volume = 50 ml); (b) Colour maps of culture medium vorticity magnitude values. Moreover, computational simulations allowed to verify that the generated microgravity condition [Gerecht-Nir, 2004] avoids shear stress values critical for the cells (maximum shear stress = 0.4 Pa). In the near future, experimental tests with hydrogel microspheres seedeed with cardiac cells will be performed. The present work is carried out in the scope of BIOSCENT European Project (ID 214539).
Results and Discussions Findings from computational simulations allowed to optimize the bioreactor geometry, and to identify the operating conditions for the preliminary tests
References Li Z. et al, Polymers, 3:740-761, 2011.Gerecht-Nir S. et al, Biotechnol Bioeng, 86(5):493-502, 2004.
ESB2012: 18th Congress of the European Society of Biomechanics
Journal of Biomechanics 45(S1)