Mußbach Franziska, Settmacher Utz, Dirsch Olaf, Xie Chichi, Dahmen Uta
Experimental Transplantation Surgery, Department of General, Visceral and Vascular Surgery, University Hospital Jena, Jena, Germany.
Eur Surg Res. 2016;57(3-4):224-239. doi: 10.1159/000446211. Epub 2016 Jul 27.
Organ engineering is a new innovative strategy to cope with two problems: the need for physiological models for pharmacological research and donor organs for transplantation. A functional scaffold is generated from explanted organs by removing all cells (decellularization) by perfusing the organ with ionic or nonionic detergents via the vascular system. Subsequently the acellular scaffold is reseeded with organ-specific cells (repopulation) to generate a functional organ.
This review gives an overview of the state of the art describing the decellularization process, the subsequent quality assessment, the repopulation techniques and the functional assessment. It emphasizes the use of scaffolds as matrix for culturing human liver cells for drug testing. Further, it highlights the techniques for transplanting these engineered scaffolds in allogeneic or xenogeneic animals in order to test their biocompatibility and use as organ grafts. Key Messages: The first issue is the so-called decellularization, which is best explored and resulted in a multitude of different protocols. The most promising approach seems to be the combination of pulsatile perfusion of the liver with Triton X-100 and SDS via hepatic artery and portal vein. Widely accepted parameters of quality control include the quantitative assessment of the DNA content and the visualization of eventually remaining nuclei confirmed by HE staining. Investigations regarding the composition of the extracellular matrix focused on histological determination of laminin, collagen, fibronectin and elastin and remained qualitatively. Repopulation is the second issue which is addressed. Selection of the most suitable cell type is a highly controversial topic. Currently, the highest potential is seen for progenitor and stem cells. Cells are infused into the scaffold and cultured under static conditions or in a bioreactor allowing dynamic perfusion of the scaffold. The quality of repopulation is mainly assessed by routine histology and basic functional assays. These promising results prompted to consider the use of a liver scaffold repopulated with human cells for pharmacological research. Transplantation of the (repopulated) scaffold is the third topic which is not yet widely addressed. Few studies report the heterotopic transplantation of repopulated liver tissue without vascular anastomosis. Even fewer studies deal with the heterotopic transplantation of a scaffold or a repopulated liver lobe. However, observation time was still limited to hours, and long-term graft survival has not been reported yet. These exciting results emphasize the potential of this new and promising strategy to create physiological models for pharmacological research and to generate liver grafts for the transplant community to treat organ failure. However, the scientific need for further development in the field of liver engineering is still tremendous.
器官工程是一种应对两个问题的新型创新策略：药理学研究所需的生理模型以及移植所需的供体器官。通过经由血管系统用离子或非离子洗涤剂灌注器官来去除所有细胞（去细胞化），从而从离体器官生成功能性支架。随后，将器官特异性细胞重新接种到脱细胞支架上（再细胞化）以生成功能性器官。
本综述概述了当前的技术水平，描述了去细胞化过程、随后的质量评估、再细胞化技术和功能评估。它强调了使用支架作为培养人肝细胞进行药物测试的基质。此外，它突出了将这些工程化支架移植到同种异体或异种动物中以测试其生物相容性并用作器官移植物的技术。关键信息：第一个问题是所谓的去细胞化，对此已进行了充分探索并产生了多种不同方案。最有前景的方法似乎是通过肝动脉和门静脉用Triton X - 100和SDS对肝脏进行搏动灌注。广泛接受的质量控制参数包括DNA含量的定量评估以及通过苏木精 - 伊红染色确认最终残留细胞核的可视化。关于细胞外基质组成的研究主要集中在层粘连蛋白、胶原蛋白、纤连蛋白和弹性蛋白的组织学测定上，且仍为定性研究。再细胞化是要解决的第二个问题。选择最合适的细胞类型是一个极具争议的话题。目前，祖细胞和干细胞具有最高潜力。将细胞注入支架并在静态条件下或在允许对支架进行动态灌注的生物反应器中培养。再细胞化的质量主要通过常规组织学和基本功能测定来评估。这些有前景的结果促使人们考虑使用接种了人细胞的肝脏支架进行药理学研究。（再细胞化后的）支架移植是第三个尚未得到广泛研究的主题。很少有研究报道无血管吻合的再细胞化肝组织的异位移植。处理支架或再细胞化肝叶异位移植的研究更少。然而，观察时间仍限于数小时，尚未有长期移植物存活的报道。这些令人兴奋的结果强调了这种新的且有前景的策略在创建药理学研究生理模型以及为移植界生成肝脏移植物以治疗器官衰竭方面的潜力。然而，肝脏工程领域进一步发展的科学需求仍然巨大。
