Department of Cardiovascular Surgery and Research Group for Experimental Surgery, Heinrich Heine University, Medical Faculty, Moorenstrasse 5, Duesseldorf D-40225, Germany.
Biomaterials. 2013 Aug;34(25):6015-26. doi: 10.1016/j.biomaterials.2013.04.037. Epub 2013 May 15.
Decellularization is a promising option to diminish immune and inflammatory response against donor grafts. In order to accelerate the autologous in vivo recellularization of aortic conduits for an enhanced biocompatibility, we tested fibronectin surface coating in a standardized rat implantation model. Detergent-decellularized rat aortic conduits (n = 36) were surface-coated with covalently Alexa488-labeled fibronectin (50 μg/ml, 24 h) and implanted into the systemic circulation of Wistar rats for up to 8 weeks (group FN; n = 18). Uncoated implants served as controls (group C; n = 18). Fibronectin-bound fluorescence on both surfaces of the aortic conduits was persistent for at least 8 weeks. Cellular repopulation was examined by histology and immunofluorescence (n = 24). Luminal endothelialization was significantly accelerated in group FN (p = 0.006 after 8 weeks), however, local myofibroblast hyperplasia with significantly increased ratio of intima-to-media thickness occurred (p = 0.0002 after 8 weeks). Originating from the adventitial surface, alpha-smooth muscle actin and desmin positive cell invasion into the media of fibronectin-coated conduits was significantly increased as compared to group C (p < 0.0001). In these medial areas, in situ zymography revealed enhanced matrix metalloproteinase activity. In both groups, inflammatory cell markers (CD3 and CD68) and signs of thrombosis proved negative. With regard to several markers of cell adhesion, inflammation and calcification, quantitative real-time PCR (n = 12) revealed no significant inter-group differences. Fibronectin surface coating of decellularized cardiovascular implants proved feasible and persistent for at least 8 weeks in the systemic circulation. Biofunctional protein coating accelerated the autologous in vivo endothelialization and induced a significantly increased medial recellularization. Therefore, this strategy may contribute to the improvement of current clinically applied bioprostheses.
去细胞化是减少供体移植物免疫和炎症反应的一种很有前途的选择。为了加速自体体内再内皮化主动脉移植物以提高生物相容性，我们在标准化大鼠植入模型中测试了纤维连接蛋白表面涂层。用共价 Alexa488 标记的纤维连接蛋白（50 μg/ml，24 h）对去污剂去细胞化的大鼠主动脉移植物（n = 36）进行表面涂层，并将其植入 Wistar 大鼠的全身循环中长达 8 周（FN 组；n = 18）。未涂层的植入物作为对照（C 组；n = 18）。纤维连接蛋白结合荧光在主动脉移植物的两个表面上至少持续 8 周。通过组织学和免疫荧光检查细胞再定植（n = 24）。FN 组的管腔内皮化明显加快（8 周后 p = 0.006），然而，局部肌成纤维细胞增生，内膜与中膜厚度比显著增加（8 周后 p = 0.0002）。源自外膜表面，α-平滑肌肌动蛋白和结蛋白阳性细胞浸润到纤维连接蛋白涂层移植物的中膜明显增加，与 C 组相比（p < 0.0001）。在这些中膜区域，原位酶谱分析显示基质金属蛋白酶活性增强。在两组中，炎症细胞标志物（CD3 和 CD68）和血栓形成迹象均为阴性。关于细胞黏附、炎症和钙化的几个标志物，定量实时 PCR（n = 12）显示组间无显著差异。在全身循环中，纤维连接蛋白表面涂层的去细胞心血管植入物是可行且至少持续 8 周的。生物功能蛋白涂层加速了自体体内的内皮化，并诱导了明显增加的中膜再细胞化。因此，这种策略可能有助于改善当前临床应用的生物假体。
