Characterization Of Novel Pneumatic Mixing For Single-Use Bioreactor Application

The novel bioreactor system from PBS Biotech®, which incorporates the patented Air-WheelTM technology, promotes uniform and homogeneous mixing and offers a low shear environment for cell culture, as evidenced by mixing time tests and computational fluid dynamics (CFD) modeling performed over a wide range of working volumes. Recent biological tests performed at various beta test sites have also shown scalable growth performance for a high cell density process in 3L and 15L PBS systems, successful baculovirus expansion in insect cells in the 3L PBS system, and comparable growth and product performance in the 250L PBS system against a 300L stirred-tank system using an Fc-fusion protein-producing process.

PBS bioreactor systems are the first with a pneumatic mixing device powered solely by gas buoyancy, eliminating the need for an external mechanical agitator. The patented design of the Air-Wheel mixing device promotes not only high tangential fluid flow around the wheel but also efficient radial and axial flow. The leverage effect of the Air-Wheel mixing device allows lower gassing requirement (v/v) with increasing working volume.

Scalable Bioreactor System

95% mixing time was calculated in PBS systems ranging from 2L to 5,000L working volume by measuring the change in conductivity readings from bolus additions of concentrated salt solution.

Mixing times were found to be between 20 sec and 62 sec over a wide range of working volumes in the PBS systems, significantly shorter than reported values in conventional stirred tank systems.