Sambanis A, Papas K K, Flanders P C, Long R C, Kang H, Constantinidis I
School of Chemical Engineering, Georgia Institute of Technology, Atlanta 30332-0100.
Cytotechnology. 1994;15(1-3):351-63. doi: 10.1007/BF00762410.
A promising method for diabetes treatment is the implantation of immunoisolated cells secreting insulin in response to glucose. Cell availability limits the application of this approach at a medically-relevant scale. We explore the use of transformed cells that can be grown to large homogeneous populations in developing artificial pancreatic tissues. We also investigate the use of NMR in evaluating, non-invasively, cellular bioenergetics in the tissue environment. The system employed in this study consisted of mouse insulinoma beta TC3 cells entrapped in calcium alginate/poly-L-lysine (PPL)/alginate beads. The PPL layer imposed a molecular weight cutoff of approximately 60 kDa, allowing nutrients and insulin to diffuse through but excluding high molecular weight antibodies and cytotoxic cells of the host. We fabricated a radiofrequency coil that can be double-tuned to 1H and 31P, and an NMR-compatible perfusion bioreactor and support circuit that can maintain cells viable during prolonged studies. The bioreactor operated differentially, was macroscopically homogeneous and allowed the acquisitions of 1H images and 31P NMR spectra in reasonable time intervals. Results indicated that entrapment had little effect on cell viability; that insulin secretion from beads was responsive to glucose; and that the bioenergetics of perfused, entrapped cells were not grossly different from those of cells never subjected to the immobilization procedure. These findings offer promise for developing an artificial pancreatic tissue for diabetes treatment based on continuous cell lines.
一种很有前景的糖尿病治疗方法是植入能响应葡萄糖分泌胰岛素的免疫隔离细胞。细胞的可获得性限制了这种方法在医学相关规模上的应用。我们探索使用能在人工胰腺组织发育过程中生长为大量同质群体的转化细胞。我们还研究了利用核磁共振（NMR）在组织环境中无创评估细胞生物能量学的方法。本研究中使用的系统由包裹在海藻酸钙/聚-L-赖氨酸（PPL）/海藻酸盐珠中的小鼠胰岛素瘤β TC3细胞组成。PPL层设定了约60 kDa的分子量截留值，允许营养物质和胰岛素扩散通过，但排除宿主的高分子量抗体和细胞毒性细胞。我们制作了一个可双调谐到1H和31P的射频线圈，以及一个与NMR兼容的灌注生物反应器和支持电路，该电路能在长时间研究过程中维持细胞存活。该生物反应器以差异方式运行，宏观上是均匀的，并能在合理的时间间隔内采集1H图像和31P NMR谱。结果表明，包封对细胞活力影响很小；珠中胰岛素分泌对葡萄糖有反应；灌注的包封细胞的生物能量学与未经过固定程序的细胞相比没有明显差异。这些发现为基于连续细胞系开发用于糖尿病治疗的人工胰腺组织带来了希望。
