Polykandriotis E, Arkudas A, Euler S, Beier J P, Horch R E, Kneser U
Abteilung für Plastische und Handchirurgie, Universitätsklinikum Erlangen, Erlangen.
Handchir Mikrochir Plast Chir. 2006 Aug;38(4):217-23. doi: 10.1055/s-2006-924419.
Experiments on animals have underlined the importance of vascularisation for biointegration and functionality of any given tissue engineering device. The aim of this investigation was to dissect the angiogenetic process in the frame of axial neovascularisation of a xenogenic solid matrix. The ultimate goal of this series of studies is the application of cells onto a prevascularised matrix, with the ambition to enhance cell survival after transplantation in vivo.
We performed a study in the rat with different vascular configurations in an isolation chamber. A disc-formed biogenic hard matrix (9 x 5 mm) was encased into an isolation chamber made of Teflon. In group 1, an arteriovenous fistula (AV loop) between the femoral vessels was microsurgically constructed and was placed around the matrix (n = 15). In group 2, the vascular carrier had the form of an arteriovenous ligated pedicle (n = 15). Evaluation intervals were two, four and eight weeks after implantation. The modes of evaluation included histology, scanning electron microscopy of corrosion casts as well as intravital micro-magnetic resonance imaging (MRI).
The arteriovenous loop as vascular carrier revealed a higher capacity for angiogenesis over the bundle configuration. The neo-fibrovascular tissue displayed minimal inflammatory elements but dense vascularisation. Scanning electron microscopy demonstrated a vivid angiogenesis with rapid evolution of the vascular bead into mature, hierarchically organised network. Micro-MRI could be used for serial investigation in terms of flow measurements and detection of thrombosis.
The presence of a vascular bed prior to cell transplantation might protect against hypoxia-induced cellular death, especially at central portions of the matrix, and therefore ensure physiological function of the device. The generation of vascularised bioartificial tissue substitutes might offer new modalities of surgical reconstruction for use in reparative medicine.
动物实验强调了血管化对于任何给定组织工程装置的生物整合和功能的重要性。本研究的目的是剖析异种固体基质轴向新生血管形成框架内的血管生成过程。这一系列研究的最终目标是将细胞应用于预先血管化的基质上，以期提高体内移植后细胞的存活率。
我们在大鼠的隔离室中进行了一项具有不同血管配置的研究。将一个盘状生物硬基质（9×5毫米）封装在一个由特氟龙制成的隔离室内。在第1组中，通过显微外科手术构建股血管之间的动静脉瘘（AV环），并将其放置在基质周围（n = 15）。在第2组中，血管载体为动静脉结扎蒂的形式（n = 15）。评估间隔为植入后两周、四周和八周。评估方式包括组织学、腐蚀铸型扫描电子显微镜以及活体微磁共振成像（MRI）。
作为血管载体的动静脉环显示出比束状配置更高的血管生成能力。新生纤维血管组织显示出最少的炎症成分，但血管化密集。扫描电子显微镜显示出活跃的血管生成，血管珠迅速演变成成熟的、层次有序的网络。微MRI可用于在流量测量和血栓检测方面进行系列研究。
细胞移植前血管床的存在可能防止缺氧诱导的细胞死亡，尤其是在基质的中心部分，从而确保装置的生理功能。血管化生物人工组织替代物的产生可能为修复医学提供新的手术重建方式。
