Mass transfer of proteins in chromatographic media: Comparison of pure and crude feed solutions

•Adsorption of hFGF2 on Capto S is driven by significant contribution of solid diffusion.•40-fold reduction of mass transfer for hFGF2 in clarified homogenate compared to pure protein solution.•Increased viscosity and reduction of qmax are responsible for reduced mass transfer.•Prediction of BTCs can be obtained with pore diffusion as well as solid diffusion model.•Comparison of adsorption kinetics of hFGF2 on grafted and macro-porous media. Elucidation of intraparticle mass transfer mechanisms in protein chromatography is essential for process design. This study investigates the differences of adsorption and diffusion parameters of basic human fibroblast factor 2 (hFGF2) in a simple (purified) and a complex (clarified homogenate) feed solution on the grafted agarose-based strong cation exchanger Capto S. Microscopic investigations using confocal laser scanning microscopy revealed slower intraparticle diffusion of hFGF2 in the clarified homogenate compared to purified hFGF2. Diffusive adsorption fronts indicated a strong contribution of solid diffusion to the overall mass transfer flux. Protein adsorption methods such as batch uptake and shallow bed as well as breakthrough curve experiments confirmed a 40-fold reduction of the mass transfer flux for hFGF2 in the homogenate compared to pure hFGF2. The slower mass transfer was induced by components of the clarified homogenate. Essentially, the increased dynamic viscosity caused by a higher concentration of dsDNA and membrane lipids in the clarified homogenate contributed to this decrease in mass transfer. Moreover, binding capacity for hFGF2 was much lower in the clarified homogenate and substantially decreased the adsorbed phase driving force for mass transfer.