A novel microfluidic-based approach to study protein stability behavior in highly concentrated and viscous (HCV) systems

The protein stability in protein-based therapeutic injectables (typically highly concentrated and viscous (HCV) solutions) is essential, as its lack determines mild to severe immune response in patients. Commonly, protein stabilization is attempted by adding stabilizers to the biomolecule solutions that are consequently studied by being exposed to physico-chemical solicitations to induce protein destabilization. Standard protocols to study protein HCV solutions rely on batch approaches, that exhibit poor controllability and are time- and reagent-consuming. Because of this and due to the rheological complexity of these fluids, there is still poor scientific knowledge about the correlation between protein stability in HCV systems and destabilization factors. Also, just a little is known about the role and the interaction of stabilizing agents with biomolecule in solution. Here a novel miniaturized approach based on microfluidics to study protein behavior in HCV systems is proposed. While requiring minimum solution volumes to be processed, the automated microfluidic platform can stimulate HCV protein solutions, offering fine controllability of stimulating environment in a wide viscosity range and in a broad spectrum of thermal and mechanical stimuli. As proof of concept, some results from light scattering-based analysis comparing stimulated and unstimulated HCV BSA solutions are presented.