Biofabrication：新型3D打印技术或可帮助治疗1型糖尿病

  近日，一篇发表于国际杂志Biofabrication上的研究论文中，来自荷兰的研究者通过研究利用3D打印技术成功地治疗了1型糖尿病；这种3D打印技术名为“生物测绘”（bioplotting），其可以帮助治疗那些经历严重低血糖事件的个体，据英国糖尿病协会数据显示，低血糖事件会影响大约三分之一的1型糖尿病患者的健康。
  文章中，研究者在胰腺中发现了一系列负责产生胰岛素和胰高血糖素的特殊细胞的工作机理，这些细胞名为郎格罕氏岛，其可以被打印成3D支架，这种支架非常有希望被移植到1型糖尿病患者机体中来帮助调节血糖水平及避免低血糖发生。
  研究者通过开发出生物工程化的支架来帮助将移植的胰岛细胞运输到患者机体中，来增加胰岛移植的成功率，从而使得细胞在达到受体位点后而得到保护及发挥完全地功能；胰岛可以被嵌入特殊的三维支架，这种支架由藻酸盐/明胶和交联结构混合而成，其可以发挥完整的功能，这就意味着这种特殊支架可以作为潜在的运输工具来进行未来的移植，在3D打印期间胰岛细胞会被包含于液体水凝胶中从而就可以帮助产生多孔的三维支架。
  研究者A A van Apeldoorn表示，我们的研究结果表明，一旦在实验室中胰岛细胞从藻酸盐/明胶的支架中恢复个噢你能，其就可以产生胰岛素并且和未被打印的胰岛细胞一样可以对葡萄糖产生反应。而大孔的支架可以确保胰岛细胞在被移植入受体机体后不会随意不受控制地进行迁移。
  如果可以利用这种新型技术来改善1型糖尿病患者的治疗，那么研究者就需要开发一种移植物，在移植物中嵌入胰岛细胞；未来研究中研究者将会通过更为深入的研究来开发优化的胰岛微环境，为受体的胰岛组织提供最好的移植物。（转化医学网360zhyx.com）
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转化医学网推荐的原文摘要：

Fabrication of three-dimensional bioplotted hydrogel scaffolds for islets of Langerhans transplantation
Biofabrication     doi:10.1088/1758-5090/7/2/025009
G Marchioli1,5, L van Gurp2, P P van Krieken2, D Stamatialis6, M Engelse3, C A van Blitterswijk5, M B J Karperien1, E de Koning2, J Alblas4, L Moroni5,7 and A A van Apeldoorn1,7
In clinical islet transplantation, allogeneic islets of Langerhans are transplanted into the portal vein of patients with type 1 diabetes, enabling the restoration of normoglycemia. After intra-hepatic transplantation several factors are involved in the decay in islet mass and function mainly caused by an immediate blood mediated inflammatory response, lack of vascularization, and allo- and autoimmunity. Bioengineered scaffolds can potentially provide an alternative extra-hepatic transplantation site for islets by improving nutrient diffusion and blood supply to the scaffold. This would ultimately result in enhanced islet viability and functionality compared to conventional intra portal transplantation. In this regard, the biomaterial choice, the three-dimensional (3D) shape and scaffold porosity are key parameters for an optimal construct design and, ultimately, transplantation outcome. We used 3D bioplotting for the fabrication of a 3D alginate-based porous scaffold as an extra-hepatic islet delivery system. In 3D-plotted alginate scaffolds the surface to volume ratio, and thus oxygen and nutrient transport, is increased compared to conventional bulk hydrogels. Several alginate mixtures have been tested for INS1E β-cell viability. Alginate/gelatin mixtures resulted in high plotting performances, and satisfactory handling properties. INS1E β-cells, human and mouse islets were successfully embedded in 3D-plotted constructs without affecting their morphology and viability, while preventing their aggregation. 3D plotted scaffolds could help in creating an alternative extra-hepatic transplantation site. In contrast to microcapsule embedding, in 3D plotted scaffold islets are confined in one location and blood vessels can grow into the pores of the construct, in closer contact to the embedded tissue. Once revascularization has occurred, the functionality is fully restored upon degradation of the scaffold.