Optimization of Perfusion Bioreactor Operation for Constructing a Dynamic in vitro Model of Ovarian Cancer

Ovarian Cancer (OC) research is limited by the lack of an appropriate in vitro model of the tumor microenvironment. We utilized a perfusion bioreactor, suitable for culture of up to 40 cell-seeded scaffolds, at velocities mimicking the cellular conditions in the extracellular fluid flow, to construct a new OC model. Our hypothesis was that operating the reactor at low volumetric velocities, with vertical flow model will allow better homogenous cultivation, compared to horizontal fluid, highly affected by gravitation forces.

Velocities and shear stresses throughout the reactor body were simulated by ANSYS Fluent, at different velocities, of vertical or horizontal flow; indicating that at 50mL/h, higher homogeneity was achieved in vertical flow, compared to horizontal flow. ES-2 seeded alginate scaffolds at 50 mL/h for 3 days, were analyzed for cell viability by Presto Blue, indicating a more homogenous cellular viability when vertical flow applied, compared to horizontal flow.

RT-PCR analysis was conducted for Spingosine-1-Phosphate receptors (S1PRs), associated with OC, indicating that S1PR1 and S1PR2 levels were significantly decreased at 500 mL/h, compared to 50 mL/h; emphasizing the model sensitivity to flow velocity.

433-seeded scaffolds, cultured at 50 mL/h resulted in S1P receptor mRNA expression levels, similar to those of the primary OC samples, compared to monolayer, static and spheroid cultures.

In summary, we have developed a perfusion reactor system that at vertical flow and specific volumetric flow mimicked the solid ovarian carcinoma parameters in vivo.