Development of microfluidics as endothelial progenitor cell capture technology for cardiovascular tissue engineering and diagnostic medicine.

We have developed a unique microfluidic platform capable of capturing circulating endothelial progenitor cells (EPCs) by understanding surface chemistries and adhesion profiles. The surface of a variable-shear-stress microfluidic device was conjugated with 6 different antibodies [anti-CD34, -CD31, -vascular endothelial growth factor receptor-2 (VEGFR-2), -CD146, -CD45, and -von Willebrand factor (vWF)] designed to match the surface antigens on ovine peripheral blood-derived EPCs. Microfluidic analysis showed a shear-stress-dependent decrease in EPC adhesion on attached surface antigens. EPCs exhibited increased adhesion to antibodies against CD34, VEGFR-2, CD31, and CD146 compared to CD45, consistent with their endothelial cell-specific surface profile, when exposed to a minimum shear stress of 1.47 dyn/cm(2). Bone-marrow-derived mesenchymal stem cells and artery-derived endothelial and smooth muscle cells were used to demonstrate the specificity of the EPC microfluidic device. Coated hematopoietic specific-surface (CD45) and granular vWF antibodies, as well as uncoated bare glass and substrate (1% BSA), were utilized as controls. Microfluidic devices have been developed as an EPC capture platform using immobilized antibodies targeted as EPC surface antigens. This EPC chip may provide a new and effective tool for addressing challenges in cardiovascular disease and tissue engineering.