Numerical and experimental simulation of a dynamic-rotational 3D cell culture for stratified living tissue models

Human tissues and organs are inherently heterogeneous, and their functionality is determined by the interplay between cell types, their secondary architecture, and gradients of signalling molecules and metabolites. To mimic the dynamics of native tissues, perfusion bioreactors and microfluidic devices are widely used, enhancing cell culture viability in the core of 3D constructs. Still, most in vitro methods for drug screening include cell or tissue exposure to constant and homogeneous compound concentrations over the testing period. Moreover, a prevalent issue inhibiting the large-scale adoption of microfluidics and bioreactors is the tubing dependence to induce a perfusion regime. Here, we propose a compartmentalized rotational (CR) bioreactor for stable control over gradient tissue culture conditions. Using the CR bioreactor, adjacent culture lanes are patterned by controlled flow dynamics to enable tissue stratification. Numerical and experimental models demonstrate cell seeding dynamics, as well as culture media rotational perfusion and gradient formations. Additionally, the developed system induces vertical and horizontal rotations, which increase medium exchange and homogeneous construct maturation, allowing both perfused tubing-based and tubing-free approaches. As a proof-of-concept, experiments are accompanied by a numerical model able to simulate the cellular inoculation, growth, and dynamic cell culture in 3D scaffolds and hydrogel. The examination of a blood-brain-barrier (BBB) model demonstrates the impact of a heterotypic culture on molecular permeability under mimetic dynamic conditions. Briefly, the present work discloses the simulation of 3D dynamic cultures, and a semi-automated platform for heterotypic tissues in vitro modelling, for broad tissue engineering and drug discovery/screening applications.