Novel Method for Mechanical Characterization of Agarose Resins

Researchers from University College London have developed a novel method of characterizing the mechanical strength of agarose-based chromatography resins used in the manufacturing of biopharmaceuticals (1).

The mechanical characterization of agarose‑based resins is a vital component of ensuring robust chromatographic performance when manufacturing biopharmaceuticals. Manufacturers must ensure that chromatographic media meet a broad range of requirements before use for the separation and purification of biological products. These requirements include stability, which can be broadly split into two categories: chemical and mechanical (2). In the case of mechanical stability, it is largely dependent on the choice and composition of the base material, particle size distribution, particle porosity, and to a lesser extent, ligand and ligand deployment (3,4). 

Currently pressure-flow profiles are the most commonly used technique to characterize these properties. However, this method requires adherence to a stringent packing criteria and may require several re-packs to achieve the desired packing quality, a process further complicated by each resin having a specific packing criteria. Furthermore, the impact of wall effects on experimental set-up and the quantities of chromatography media and buffers required are a factor. Together these issues can drive up the costs of this vital process.

To address this, researchers developed a dynamic mechanical analysis (DMA) technique that utilizes the viscoelasticity of a 1-mL sample of slurry to ascertain the mechanical properties of the resin. The technique does not require the use of multiple buffers and uses a much-reduced quantity of resin that researchers believed would address the costing issues associated with pressure-flow characterization.

Utilizing the new technique to investigate the viscoelastic properties of small quantities of seven agarose-based resins, the researchers examined how the slurries responded to the strain over a fixed period of time before looking to draw correlations between the results obtained from pressure-flow and DMA experiments. Through this method researchers hoped to ascertain whether DMA can be used as a complementary technique for the mechanical characterization of chromatography media.

The results published in the Journal of Chromatography A suggested that the new technique was on par with the established pressure-flow technique when determining resin robustness and could be used as a complementary technique. Furthermore, researchers suggested the technique could also be used for the rapid testing of a range of resins post-emulsification and during the development of new resins.

References

1. M.C. Nweke, R.G. McCartney, and D.G. Bracewell, J. Chromatogr. A 1530, 129–137 (2017).
2. N. Ioannidis, Manufacturing of Agarose-Based Chromatographic Media with Controlled Pore and Particle Size. University of Birmingham (2009).
3. G. Jagschies, G. Sofer, and L. Hagel, in Handbook of Process Chromatography – Development, Manufacturing, Validation and Economics  (Elsevier, 2nd Ed., 2008).
4. M. Andersson, Characterisation of Chromatography Media Aimed for Purification of Biomolecules. Uppsala Universitet (2014).