Biomedical Engineering Department, McGill University, Montreal, QC H3A 2B4, Canada.
Lab Chip. 2012 Nov 7;12(21):4363-71. doi: 10.1039/c2lc40233e.
Here we present a microfluidic platform to generate multiplex gradients of biomolecules within parallel microfluidic channels, in which a range of multiplex concentration gradients with different profile shapes are simultaneously produced. Nonlinear polynomial gradients were also generated using this device. The gradient generation principle is based on implementing parrallel channels with each providing a different hydrodynamic resistance. The generated biomolecule gradients were then covalently functionalized onto the microchannel surfaces. Surface gradients along the channel width were a result of covalent attachments of biomolecules to the surface, which remained functional under high shear stresses (50 dyn/cm(2)). An IgG antibody conjugated to three different fluorescence dyes (FITC, Cy5 and Cy3) was used to demonstrate the resulting multiplex concentration gradients of biomolecules. The device enabled generation of gradients with up to three different biomolecules in each channel with varying concentration profiles. We were also able to produce 2-dimensional gradients in which biomolecules were distributed along the length and width of the channel. To demonstrate the applicability of the developed design, three different multiplex concentration gradients of REDV and KRSR peptides were patterned along the width of three parallel channels and adhesion of primary human umbilical vein endothelial cell (HUVEC) in each channel was subsequently investigated using a single chip.
在这里，我们展示了一种微流控平台，可在平行的微流控通道内生成生物分子的多重浓度梯度，其中同时产生了多种具有不同形状的多重浓度梯度。该设备还可产生非线性多项式梯度。梯度生成原理基于实现具有不同水动力阻力的平行通道。然后将生成的生物分子梯度共价键合到微通道表面上。通道宽度上的表面梯度是生物分子与表面共价键合的结果，在高剪切应力（50 dyn/cm(2)）下仍保持功能。将与三种不同荧光染料（FITC、Cy5 和 Cy3）偶联的 IgG 抗体用于证明生物分子的多重浓度梯度。该设备可在每个通道中生成多达三种不同的生物分子，并具有不同的浓度分布。我们还能够产生二维梯度，其中生物分子沿通道的长度和宽度分布。为了证明所开发设计的适用性，将 REDV 和 KRSR 肽的三种不同的多重浓度梯度沿三个平行通道的宽度进行图案化，然后使用单个芯片研究每个通道中原发性人脐静脉内皮细胞（HUVEC）的黏附。
