Silva, Tiago Castanheira
van Opstal, Andries
Every, Hayley A
Witkamp, Geert Jan
KAUST DepartmentBiological and Environmental Sciences and Engineering (BESE) Division
Environmental Science and Engineering Program
Water Desalination and Reuse Research Center (WDRC)
Online Publication Date2019-01-22
Print Publication Date2019-02
Permanent link to this recordhttp://hdl.handle.net/10754/631050
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AbstractIn 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 speed up at low ionic strength and high concentration gradient. This confirms the corresponding experimental observation of protein diffusion measured via the H-cell microfluidics.
CitationYu M, Silva TC, van Opstal A, Romeijn S, Every HA, et al. (2019) The Investigation of Protein Diffusion via H-Cell Microfluidics. Biophysical Journal. Available: http://dx.doi.org/10.1016/j.bpj.2019.01.014.
SponsorsThis work was supported by the Netherlands Organisation for Scientific Research, Domain Applied and Engineering Sciences (project number 12144), which is partly funded by the Ministry of Economic Affairs, the Netherlands.