The Investigation of Protein Diffusion via H-Cell Microfluidics

作者：Miao Yu, Tiago Castanheira Silva, Andries van Opstal, Stefan G. Romeijn, Hayley A. Every, Wim Jiskoot, Geert‐Jan Witkamp, Marcel Ottens · 发表于：Biophysical Journal · 年份：2019 · DOI：10.1016/j.bpj.2019.01.014 · 被引用次数：31 · 研究领域：Microfluidic and Capillary Electrophoresis Applications、Protein purification and stability、Microfluidic and Bio-sensing Technologies

In this study, we developed a microfluidics method, using a so-called H-cell microfluidics device, for the determination of protein diffusion coefficients at different concentrations, pHs, ionic strengths, and solvent viscosities. Protein transfer takes place in the H-cell channels between two laminarly flowing streams with each containing a different initial protein concentration. The protein diffusion coefficients are calculated based on the measured protein mass transfer, the channel dimensions, and the contact time between the two streams. The diffusion rates of lysozyme, cytochrome c, myoglobin, ovalbumin, bovine serum albumin, and etanercept were investigated. The accuracy of the presented methodology was demonstrated by comparing the measured diffusion coefficients with literature values measured under similar solvent conditions using other techniques. At low pH and ionic strength, the measured lysozyme diffusion coefficient increased with the protein concentration gradient, suggesting stronger and more frequent intermolecular interactions. At comparable concentration gradients, the measured lysozyme diffusion coefficient decreased drastically as a function of increasing ionic strength (from zero onwards) and increasing medium viscosity. Additionally, a particle tracing numerical simulation was performed to achieve a better understanding of the macromolecular displacement in the H-cell microchannels. It was found that particle transfer between the two channels tends to...