Mechanistic understanding of biomolecules adsorption: theory and applications
The request for mechanistic understanding of processes has completely changed the paradigm of process development and process validation in biopharmaceutical manufacturing. For chromatographic separation processes the equilibrium binding conditions, also referred to as adsorption isotherms, are important to get a theoretical understanding on the maximum possible binding capacity and are the basis for mathematical description of the separation processes. In this pre-conference workshop we will provide the theoretical basis and the state-of-the-art in experimental approaches to monitor biomolecule – surface interactions. The participants will be offered an overview of different techniques: conventional adsorption measurements with finite and infinite bath, florescence assays, Surface Plasmon Resonance (SPR), Differential Scanning Calorimetry (DSC), Isothermal Titration Calorimetry (ITC), Flow Microcalorimetry (FMC) and Small Angle X-ray scattering (SAX). Specific advantages and drawbacks for each of the techniques to shed light on biomolecule mechanism of adsorption will be discussed. Focus will be put on FMC and SAX, as two non-labeling techniques capable of simulating a dynamic chromatography system allowing online and in situ monitoring of the adsorptive process. Finally, we will cover present applications of these in situ monitoring techniques to better understand antibodies separation by affinity chromatography with protein A, hydrophobic interaction chromatography and ion-exchange chromatography highlighting current challenges as well as future opportunities.