Protein partitioning and transport in supported cationic acrylamide-based hydrogels

• Published in: AIChE journal 2003-05, Vol.49 (5), p.1168-1177
• Main Authors: Russell, Shawn M., Belcher, Emily B., Carta, Giorgio
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biotechnology; Fundamental and applied biological sciences. Psychology; Methods. Procedures. Technologies; Others; Various methods and equipments
• ISSN: 0001-1541; 1547-5905
• DOI: 10.1002/aic.690490510

The partitioning and transport of myoglobin in cationic, acrylamide‐based hydrogels are studied by a microscopic visualization method. Homogeneous cationic gels are synthesized inside fused‐silica capillaries with a square section, which allow a direct determination of protein concentration profiles during transient adsorption and desorption. Diffuse, self‐similar profiles are observed and used to determine the equilibrium protein binding capacity and the protein diffusivity in the gel. Mass‐transfer rates are found to be essentially independent of the external solution concentration, but to vary dramatically with the gel polymer concentration. A Fickian diffusion model with a flux based on the adsorbed‐phase concentration gradient is consistent with the experimentally determined concentration profiles for both positive and negative protein concentration steps. The equilibrium and rate parameters determined for the capillary‐supported gels also compare favorably with those obtained from macroscopic measurements using composite ion‐exchange media comprising similar gels held within the pores of porous silica particles.