Numerical optimization of cell colonization modelling inside scaffold for perfusion bioreactor: A multiscale model

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Cell Biology

Background:

• Clinically applicable bone graft substitutes utilize mechanical stimulation via flow-perfusion in cell-seeded scaffolds.
• Fluid flow is critical for nutrient delivery and cell colonization in these systems.
• Multiscale modeling is a common approach to link physical factors like wall shear stress and flow rate across different scales.

Purpose of the Study:

• To develop a multiscale model for determining the optimal inlet flow rate for cultivating osteoblast-like cells in macroporous biomaterials within a perfusion bioreactor.
• To investigate the influence of Wall Shear Stress (WSS) on cell colonization at the macroscale.
• To predict optimal conditions for cell seeding and proliferation in bone tissue engineering scaffolds.

Main Methods:

• Development of a multiscale model integrating microscale and macroscale physical quantities.
• Focus on the relationship between Wall Shear Stress and cell colonization prediction.
• Interpolation of microscale results to the macroscale to identify optimal flow rates.

Main Results:

• The model predicts a cell colonization of 325% after 7 days of cell culture.
• Optimal conditions were determined for a macroporous scaffold with specific pore and interconnection diameters (>350 μm and 150 μm, respectively).
• A constant inlet flow rate of 0.69 mL·min⁻¹ was identified as optimal for enhanced cell colonization.

Conclusions:

• The developed multiscale model effectively predicts cell colonization in perfusion bioreactors.
• The protocol is adaptable to various porous biomaterials and dynamic cell culture systems.
• This approach facilitates the optimization of bone graft substitute development through controlled mechanical stimulation.