Šints Viesturs, Cīmurs Jānis, Birjukovs Mihails, Driķis Ivars, Goluba Karīna, Jēkabsons Kaspars, Parfejevs Vadims, Riekstiņa Una, Mozoļevskis Gatis, Rimša Roberts, Kitenbergs Guntars
Laboratory of Magnetic Soft Materials, University of Latvia, Riga, Latvia.
Faculty of Medicine and Life sciences, University of Latvia, Riga, Latvia.
PLoS One. 2025 Jun 17;20(6):e0322069. doi: 10.1371/journal.pone.0322069. eCollection 2025.
Creating a physiologically relevant shear stress in organ-on-a-chip (OOC) devices requires careful tailoring of microfluidic flow parameters. Currently, it is fairly common to use a simple approximation assuming constant viscosity, even for serum-based media. Here, we show that a popular nutrient solution (Dulbecco's Modified Eagle Medium supplemented with Fetal Bovine Serum) requires a more complex treatment (i.e., is a non-Newtonian fluid), with observed shear stress values significantly greater than reported in literature. We measure the rheology of the solutions and combine it with a 3-dimensional flow field measurement to derive shear stress at the channel surface. We verify the experiments with numerical simulations, finding good agreement and deriving flow properties. Finally, we provide relevant expressions for the shear stress approximation, suitable for development of OOC devices with various geometries.
在芯片器官（OOC）装置中创建与生理相关的剪切应力需要仔细调整微流体流动参数。目前，即使对于基于血清的培养基，使用假设粘度恒定的简单近似方法也相当普遍。在这里，我们表明一种流行的营养液（补充有胎牛血清的杜尔贝科改良伊格尔培养基）需要更复杂的处理（即它是一种非牛顿流体），观察到的剪切应力值明显大于文献报道的值。我们测量了溶液的流变学，并将其与三维流场测量相结合，以得出通道表面的剪切应力。我们通过数值模拟验证了实验，发现结果吻合良好并得出了流动特性。最后，我们提供了剪切应力近似的相关表达式，适用于开发具有各种几何形状的OOC装置。
