Bioartificial devices for treatment of neurologic diseases

据报道，帕金森病可以通过移植多巴胺释放细胞来治疗，而终末期癌症患者的严重疼痛可以通过移植吗啡释放细胞来缓解。免疫反应最有可能是移植异体和异种细胞失败的原因。为了克服这一问题，细胞被包裹在半透聚合物膜中后进行移植，该膜必须对氧气、营养物质和生物活性物质等小分子具有渗透性，但对淋巴细胞、免疫球蛋白和补体蛋白不具渗透性。此外，在中枢神经系统内很难找到大容量移植的空间。因此，细胞聚集体的CEN三离体微胶囊化被研究以解决这些问题。将球形细胞聚集体悬浮到藻酸盐溶液中。在内径14 mm的12ml玻璃试管中，自上而下将0.4ml的混悬液覆盖在由2.5ml7wt%的葡聚糖、0.5mlBaCl2溶液和0.5ml13wt%的葡聚糖组成的三层上。将试管在170×g的温度下离心10分钟，将聚集体旋转到试管底部。这种方法可以有效地将细胞聚集体包裹在非常薄的微胶囊中，而不会污染空的微囊，试管法不适用于大量细胞聚集体的微胶囊化。研制了一种特殊的离心机。它操作简单，能有效地微胶囊化大量的细胞聚集体，但从离心机中收集微胶囊化聚集体是一个需要解决的问题。

It has been reported that Parkinson's disease can be treated by transplantation of dopamine releasing cells and sever pain of end stage cancer patients can be alleviated by transplanting morphine releasing cells. Immunological reactions are most likely to be the reason for failure when transplanting allogeneic and xenogeneic cells. To overcome this problem, cells are transplanted after they are enclosed into a semipermeable polymer membrane, which must be permeable to small molecules such as oxygen, nutrients and bioactive substances, but impermeable to lymphocytes and immunoglobulins and complement proteins. In addition, it is difficult to find space for a large volume of transplant in central nerve system. Therefore, cen trifugal microencapsulation of cell aggregates was examined to solve these problems. Spherical cell aggregates were suspended into the alginate solution. 0.4 ml of the suspension was over-layed on the top of three layers composed of a 2.5 ml layer of 7 wt% dextran, a 0.5 ml layer of BaCl2 solution and a 0.5 ml layer Of 13 wt% dextran from the top in a 12 ml glass test-tube of 14 mm inner diameter. The test-tube was centrifuged at 170 x g for 10 min to spin the aggregates to the bottom of the tube. This procedure can effectively enclose cell aggregates in microcapsules with a very thin wall without contamination of empty microcapsules.The test-tube method can't be applied to microencapsulation of a large number of cell aggregates. A special centrifuge was developed. It can easily be operate and effectively microencapsulate a large number of cell aggregates, but there is a problem to solve in collecting microencapsulated aggregates from the centrifuge.