Experimental collision efficiencies of polymer-flocculated animal cells

Area of Science:

• Bioprocess Engineering
• Colloid and Surface Science
• Cell Biology

Background:

• Understanding particle collision kinetics is crucial for optimizing flocculation processes.
• Hybridoma cell flocculation is vital for biopharmaceutical production.
• Poly-L-histidine is used as a flocculant for hybridoma cells.

Purpose of the Study:

• To investigate the effects of flocculation conditions on the collision efficiency of hybridoma cells.
• To correlate collision efficiency with cell zeta potential and hydrodynamic factors.
• To elucidate the role of polymer distribution in cell collision.

Main Methods:

• Experimental determination of collision efficiency in Couette flow.
• Varying flocculation conditions, including polymer dose and shear rate.
• Analysis of cell zeta potential and surface coverage.

Main Results:

• Collision efficiency correlates with cell zeta potential to the -2.4 power at high surface coverage.
• Polymer distribution correction is needed for accurate low-coverage behavior.
• Collision efficiency shows weak dependence on hydrodynamic conditions at high coverage.
• Strong dependence on viscous fluid forces observed at low coverage.
• Weak intercell bonding influences results across surface coverages.
• Steric hindrance observed with high molecular weight dextrans.

Conclusions:

• Flocculation conditions significantly impact hybridoma cell collision efficiency.
• Zeta potential and hydrodynamic forces are key determinants of collision.
• Understanding these kinetics aids in optimizing cell harvesting and bioprocesses.