Consigny P M, Silverberg D A, Vitali N J
Department of Radiology, Jefferson Medical College and Thomas Jefferson University Hospital, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
J Vasc Interv Radiol. 1999 Feb;10(2 Pt 1):155-63. doi: 10.1016/s1051-0443(99)70458-6.
The purpose of this study was to determine if the luminal surface of balloon-dilated arteries can be re-endothelialized circumferentially with use of normal endothelial cells (ECs) and superparamagnetic microsphere-containing endothelial cells (MagECs) to cover gravity-dependent and independent arterial surfaces, respectively.
MagECs were obtained after phagocytosis of albumin-coated superparamagnetic polystyrene microspheres by rabbit microvascular ECs. The effect of microsphere internalization on cell adhesion was determined in vitro by comparing ECs and MagECs in terms of time courses of adhesion to fibronectin and cell retention after exposure to a shear stress. In vivo re-endothelialization was performed by delivering fluorescently labeled ECs and MagECs to a balloon-dilated artery with a double-balloon catheter, placing a magnet over the artery, and rotating the rabbit axially. Endoluminal coverage of arterial cross-sections was estimated by epifluorescence microscopy.
Under the influence of gravity, in vitro cell adhesion to fibronectin after 5, 10, and 15 minutes was similar for the ECs (34%, 74%, and 70%) and MagECs (40%, 56%, and 93%). In vitro cell retention after exposure to a shear stress (25 dynes/cm2) was greater (P < .05) for ECs than for MagECs (82% vs 69%). Use of ECs plus MagECs in vivo resulted in cell delivery that was nearly circumferential.
Delivery of a mixture of ECs and MagECs in combination with animal rotation and a magnetic field provide nearly circumferential delivery of ECs to the luminal surface of balloon-dilated arteries. The presence of superparamagnetic microspheres in cells does not impede cell adhesion but does decrease cell retention after exposure to a fluid shear.
本研究的目的是确定使用正常内皮细胞（ECs）和含超顺磁性微球的内皮细胞（MagECs）分别覆盖重力依赖和非依赖的动脉表面，球囊扩张动脉的管腔表面是否能周向重新内皮化。
兔微血管内皮细胞吞噬白蛋白包被的超顺磁性聚苯乙烯微球后获得MagECs。通过比较ECs和MagECs对纤连蛋白的黏附时间进程以及暴露于剪切应力后的细胞保留情况，在体外确定微球内化对细胞黏附的影响。通过使用双球囊导管将荧光标记的ECs和MagECs输送到球囊扩张的动脉中，在动脉上方放置一块磁铁，并使兔子轴向旋转，进行体内重新内皮化。通过落射荧光显微镜估计动脉横截面的腔内覆盖情况。
在重力影响下，体外5分钟、10分钟和15分钟后ECs（34%、74%和70%）和MagECs（40%、56%和93%）对纤连蛋白的细胞黏附情况相似。暴露于剪切应力（25达因/平方厘米）后，ECs的体外细胞保留率高于MagECs（82%对69%，P <.05）。在体内使用ECs加MagECs导致细胞输送几乎呈周向分布。
将ECs和MagECs的混合物与动物旋转和磁场相结合进行输送，可使ECs几乎周向地输送到球囊扩张动脉的管腔表面。细胞中超顺磁性微球的存在并不妨碍细胞黏附，但会降低暴露于流体剪切后细胞的保留率。
