The Study Of Ex Vivo Experiment Device And Method Uesd For Capturing Endothelial Progenitor Cells

Cardiovascular diseases have severely threatenedhuman health and are the leading cause of death globally.Currently,interventional therapy is the main treatment method of cardiovascular diseases,however,clogged arteries propped open with the intravascular stent will cause vascular intimal injury,and lead to the generation of late thrombosis and restenosis bare metal stents are not able to satisfy clinical needs anymore,andthe study focus of numerous researchers has changed to surface modification of stents,which can promote endothelial cell growth,capture endothelial progenitor cells in peripheral blood and induce endothelialization on the stent.Microenvironment is an important factor to induce endothelialization.In addition to capture endothelial progenitor cells,induce directed differentiation and maintainproliferation,how to evaluate the capture efficiency of the microenvironment to endothelial progenitor cells or mesenchymal stem cells has become a bottleneck in the optimization of microenvironment built in situ.The current in vitro dynamic capture experiments such as the dynamic capture of endothelial progenitor cells in a flow chamber have obtained effectiveness.It mimicked the capture of endothelial progenitor cells in human blood flow under the dynamic shear force and could function for a certain time period.Nevertheless,the fluid dynamics and rheological status ofBut the cycle of artificial cell solution could not be compared with that of and flow velocity couldn't perfectly correspond to the human real blood in vivo.Besides,the common in vivo animal evaluation includes the implant of stents inside the animal blood vessels and allow contact with blood vessels for a long time,which would cause the migration and proliferation of endothelial cells from vessel wall to stent surface.And consequently,researchers are unable to determine whether the cells on the surface of the stents are differentiated from endothelial progenitor cells captured from the peripheral blood orfrom the migration and proliferation of endothelial cellson vessel wall after a long time implantation.Thus,the objective of this study was to design an experiment method that could separately evaluate the capture of endothelial progenitor cellsfrom peripheral blood by implantedstents,and meanwhile,avoid the interference of the endothelial cells in blood vessel wall,i.e.,ex vivo experiment method.In this study,we explored and set up an experiment thatinduced the blood flow out of animal andflow back through an ex vivo experiment device.This study consisted of three parts.1.Design an exvivo experiment device for the evaluation of implant materials,which could be used to mimic the blood circulation of animals and to capture the endothelial progenitor cells in the blood.The device design includes(1)single channel,dual-channel,four-channel device;(2)hose as the equipment material to connect the proximal and distal blood vessel,and keptblood circulation still in laminar flow state;(3)samples in the device wereadhered to the wall,which could more accurately mimic the homing of endothelial progenitor cells to the vascular wall,and the inner lumen was still in a smooth circular morphology after the placement of the stents.2.Preliminary study of the exvivo experiment.The study included(1)selection of rabbits as research objects;(2)dissection and vascular diameter measurement of three main animal blood vessels;chosen of carotid artery as the intubation site;(3)selection of low molecular heparin as the anticoagulant of extracorporeal circulation;(4)exploration of the puncture method,fixing technique and circulation control parameters in the ex vivo experiment;(5)application of dual-channel and four-channel device in the ex vivo experiment,summarization of problems occurred in the experiment.3.New study using SD rats as the animal model in the ex vivo experiment.And rated the capture efficiency of endothelial progenitor cells in different animals.The study included(1)design of the ex vivo experiment device(single and dual-channel)that was compatible with the SD rat;(2)dissection and blood vessel measurementof the SD rat,selection of the abdominal aorta as the intubation site;(3)application of single channel and dual-channel device in the ex vivo experiment,and discussion of the problems occurred in the process.Above all,the ex vivo experiment is a new method to evaluate the capture of endothelial progenitor cells,and in this paper we designed an ex vivo experiment device and explored a series of ex vivo experiments.Finally we obtained a new method for the research and evaluation of inducing endothelialization,and using this method we can more accurately evaluate evaluate the capture efficiency of the surface microenvironment to endothelial progenitor cells.