Davies J E, James R F, London N J, Robertson G S
Department of Surgery, University of Leicester, United Kingdom.
Transplantation. 1995 Mar 15;59(5):767-71. doi: 10.1097/00007890-199503150-00022.
Purification of islets based on the physical differences in density between exocrine and islet tissue reduces islet yields and remains one of the factors limiting islet transplantation. Immunomagnetic cell separation methods provide an attractive, highly specific alternative capable of rapid, gentle, high volume cell separation, but they require modification to be applied effectively to separation of the much larger tissue fragments involved in islet purification. In this study, mAb to rat exocrine tissue were coupled to 4.5-microns magnetic beads (M450 Dynabeads), before incubation with standard aliquots of rat pancreatic digest. The effect on immunomagnetic islet purification of modifications in the magnetic field and the method of digest release into the field were investigated. The results showed that using vibration to maintain the immunomagnetically labeled digest in suspension in tissue culture medium whose density had been increased by the addition of BSA, significantly improved the purification process. When the digest suspension was slowly released and allowed to drift under gravity through a magnetic field applied across a narrow tube, the use of a quadripole of permanent magnets improved results compared with bipolar or unipolar magnetic fields. By modifying immunomagnetic cell separation techniques in this way, a median islet yield of 77% could be reliably achieved while removing 88% of the contaminating exocrine tissue. The use of such methods in human islet purification would significantly increase the yield of islets from each donor pancreas and increase the success rate of transplantation from single donors.
基于外分泌组织与胰岛组织密度的物理差异来纯化胰岛会降低胰岛产量，这仍然是限制胰岛移植的因素之一。免疫磁细胞分离方法提供了一种有吸引力的、高度特异性的替代方法，能够快速、温和、大量地分离细胞，但要有效地应用于涉及胰岛纯化的更大组织片段的分离，还需要进行改进。在本研究中，将针对大鼠外分泌组织的单克隆抗体与4.5微米的磁珠（M450 Dynabeads）偶联，然后与标准等分试样的大鼠胰腺消化物孵育。研究了磁场变化以及将消化物释放到磁场中的方法对免疫磁胰岛纯化的影响。结果表明，通过振动使免疫磁标记的消化物悬浮在添加了牛血清白蛋白从而使其密度增加的组织培养基中，可显著改善纯化过程。当将消化物悬浮液缓慢释放，并使其在重力作用下通过施加在细管上的磁场漂移时，与双极或单极磁场相比，使用四极永久磁铁可改善结果。通过以这种方式改进免疫磁细胞分离技术，可可靠地实现77%的胰岛产量中位数，同时去除88%的污染外分泌组织。在人类胰岛纯化中使用此类方法将显著提高每个供体胰腺的胰岛产量，并提高单供体移植的成功率。
