Capture and Enrichment of CD34-Positive Haematopoietic Stem and Progenitor Cells from Blood Circulation Using P-Selectin in an Implantable Device.

Clinical infusion of haematopoietic stem and progenitor cells (HSPCs) is vital for restoration of haematopoietic function in many cancer patients. Previously we have demonstrated an ability to mimic physiologic cell trafficking in order to capture CD34-positive (CD34+) HSPCs using a monolayer of P-selectin in flow chambers. The aim of the current study was to determine if HSPCs could be captured directly from circulating blood in vivo. Vascular shunt prototypes, coated internally with P-selectin, were inserted into the femoral artery of rats. After one-hour blood perfusion, successful capture of mononuclear cells was achieved and analysis of these cells revealed a significant enrichment for CD34+ HSPCs. Blood flow through the cell capture device resulted in a wall shear stress of 4–6 dynes/cm². Purity of captured CD34+ cells showed 7-fold enrichment (average purity = 28 ± 4%) over levels found in the control mobilized peripheral blood mononuclear cells (average purity = 3 ± 0.5%). Robust cell capture and HSPC enrichment were also observed in devices that were implanted in a closed-loop arterio-venous shunt conformation for two hours. Adherent cells were viable and were able to differentiate into burst forming units in culture. This study demonstrates an ability to mimic the physiologic arrest of HSPCs from blood in an implantable device and may represent a practical alternative for adult stem cell capture and enrichment.