Basic study for the development of small caliber vascular prosthesis with alternately aligned static magnetic field

我们在初步研究中提出交替排列的静态磁场可以促进内皮细胞再生。在本研究中，我们从磁场强度和磁场方向的角度来评价其效果。犬颈动脉和股动脉通过向动脉内注入温和的干燥气流去除内皮。每对剥离的动脉中，有一条被磁化材料包裹，另一条被包裹在非磁化材料中。间隔一段时间后，我们收集它们进行电镜检查和测定动脉壁DNA浓度。[实验1]我们使用由长磁极和细磁极组成的两种类型的磁片。磁通量密度分别为280和360高斯。我们以两种方式应用磁片，其磁场方向平行或垂直于动脉的长轴。结果磁刺激组内皮细胞再生速度明显快于对照组。我们发现磁场强度没有显著差异。垂直施药效果优于平行施药。[实验2]我们使用了三种环形磁铁，内径为6mm，宽度为3.5 mm。1型磁体纵向磁化，2型磁体横向磁化，3型磁体周向磁化，在圆周上有10个磁极。我们用五个环形磁铁通过磁力耦合，形成一个圆柱形磁铁。结果磁刺激组内皮细胞再生面积明显大于对照组。1型磁铁内皮细胞再生较好。磁性组的DNA浓度低于对照组。这可能表明平滑肌细胞增殖的抑制是基于早期暴露的内皮下层被再生的内皮细胞覆盖。

We suggested alternately aligned static magnetikc fields could promote endothelial regeneration in a preliminary stucy. In this study, we evaluated the effect from the viewpoint of the intensity and direction of magnetic field. Canine carotid and femoral arteries were denudd of endothelium by passing a gentle stream of dry air into the arteries. One of each pair of denuded arteries was wrapped in a magnetized materials and the other was in a non-magnetized one. After a certain period of interval, we collected them for electron microscopic examination and measurement of DNA concentration in the arterial wall. [Experiment 1] We used two types of magnetic sheet consisting of long and thin magnetic poles. The magnetid flux densities were 280 and 360 Gauss. We applied the magnetic sheet in two ways that its direction of magnetic field was parallel or perpendicular to the long axis of the arteries. Results The magnetic groups showed fadster endothelial regeneration than the control group. We found the magnetic intensities made no significant difference. There was a tendency that the perpendicular application was superior to the parallel one. [Experiment 2] We used three types of ringed magnet, an internal diameter of 6 mm and a width of 3.5 mm. Type 1 magnet was magnetizd longitudinally, Type 2 was transversely and Type 3 was circumferentially, resulting in 10 poles round the circumfarence. We used five ringed magnets coupled by magnetic force, forming a cylindrical magnet. Results The area of endothelial regeneration was significantly larger in the magnetic groupsthan in the control group. Type 1 magnet showed better endothelial regeneration. The DNA concentration was lower int he magnetic groups than in the control group. This may suggest the suppression of smooth muscle cell proliferation based on the earlier covering of exposed subendothelium with regenerated endothelial cells.