Brizzola Stefano, de Eguileor Magda, Brevini Tiziana, Grimaldi Annalisa, Congiu Terenzio, Neuenschwander Peter, Acocella Fabio
Department of Veterinary Clinical Science, Faculty of Veterinary Medicine, University of Milan, Milano, Italy.
Interact Cardiovasc Thorac Surg. 2009 Jun;8(6):610-4. doi: 10.1510/icvts.2008.197012. Epub 2009 Mar 16.
We evaluated a newly designed bioresorbable polymer (Degrapol) tracheal prosthesis in an in-vivo angiogenesis-inducing animal model focusing on the specific tissue reaction, the neo-angiogenesis and also the eventual cathepsin B role during the polymer degradation. Fifteen rabbits were divided into three groups (2, 6 and 8 weeks) and our tube-shaped porous prosthesis was implanted using the common carotid artery and the internal jugular vein as vascular pedicle. Optical and electron microscopy, immunohistochemistry and immunocytochemistry were performed at the end of each period, showing cells and fibrils, in direct contact with the Degrapol scaffold, strongly increased with time. Blood vessel neoformation was visible with CD31 expression localized at the endothelial cells forming the neovascular walls. Over time many of them differentiate in muscle fibers as validated by the expression of alpha-smooth muscle actin (SMA). Few inflammatory cells, expressing CD14, were visible while most cells adopting a pronounced spreading phenotype showed a strong positivity for cathepsin B. We concluded that this bioresorbable polymer provided a good substrate for fibrous tissue deposition with an excellent degree of neo-angiogenesis. Also, cathepsin B seems to contribute to the polymer degradation and particularly to neovascularization by stimulating capillary-like tubular structures and cell proliferation.
我们在一个体内血管生成诱导动物模型中评估了一种新设计的可生物吸收聚合物（Degrapol）气管假体，重点关注特定的组织反应、新生血管生成以及聚合物降解过程中组织蛋白酶B的最终作用。将15只兔子分为三组（2周、6周和8周），并使用颈总动脉和颈内静脉作为血管蒂植入我们的管状多孔假体。在每个时间段结束时进行光学和电子显微镜检查、免疫组织化学和免疫细胞化学检查，结果显示与Degrapol支架直接接触的细胞和纤维随时间显著增加。通过CD31表达可见血管新生，其定位于形成新生血管壁的内皮细胞。随着时间的推移，其中许多细胞分化为肌纤维，α-平滑肌肌动蛋白（SMA）的表达证实了这一点。可见少数表达CD14的炎性细胞，而大多数呈现明显铺展表型的细胞对组织蛋白酶B呈强阳性。我们得出结论，这种可生物吸收聚合物为纤维组织沉积提供了良好的基质，并具有优异的新生血管生成程度。此外，组织蛋白酶B似乎通过刺激毛细血管样管状结构和细胞增殖，促进聚合物降解，特别是促进新生血管形成。
