Department of Surgery, Division of Plastic and Reconstructive Surgery, Taipei Veterans General Hospital, Taipei, Taiwan.
J Surg Res. 2011 Jun 1;168(1):9-15. doi: 10.1016/j.jss.2009.09.052. Epub 2009 Oct 23.
Tissue engineering is a promising solution for tissue defect repair. A key problem, however, is how to keep the engineered tissue alive after implantation. The ideal scaffold for tissue engineering would be biocompatible and biodegradable and, more importantly, would exhibit good interaction with endothelial cells to promote angiogenesis.
Three different scaffolds were synthesized: collagen/hyaluronic acid (HA) (MW 6.5K), collagen/HA (MW 220K), and collagen only. The synthesized collagen/HA scaffold was analyzed for water content, pore size, and HA content. An animal model for in vivo tissue construct angiogenesis was developed using the inferior epigastric skin flap of mice and perfusion of quantum dots; the average fluorescence intensity per unit area was calculated and correlated with vessel density from histologic examination.
The pore size is not statistically different among the three groups and the HA content is not statistically different between the two collagen/HA groups. The fluorescence intensity of the collagen/HA (MW 6.5K) group is increased at day 14, 21, and 28, and is significantly higher than in the other groups. Similar results were also obtained from histologic immunohistochemistry studies. CD31-stained vessels were found co-localized with QD fluorescence and these newly formed vessels were identified at day 14 in the collagen/HA (MW 6.5K) group and increased significantly at day 21 and 28.
This study showed that collagen scaffolds with short-chain HA (MW 6.5K) revascularize faster than those with long-chain HA (MW 220K) and collagen only. The results of the new animal model for studying scaffold angiogenesis are compatible with the conventional methods of immunostaining and histological examination.
组织工程是修复组织缺损的一种很有前途的解决方案。然而，一个关键问题是如何在植入后使工程组织保持活力。用于组织工程的理想支架应该是生物相容和可生物降解的，更重要的是，应该与内皮细胞有良好的相互作用，以促进血管生成。
合成了三种不同的支架：胶原/透明质酸（HA）（MW6.5K）、胶原/HA（MW220K）和仅胶原。对合成的胶原/HA 支架的含水量、孔径和 HA 含量进行了分析。采用小鼠下腹皮瓣和量子点灌注建立了体内组织构建血管生成的动物模型；计算了单位面积的平均荧光强度，并与组织学检查的血管密度相关联。
三组之间的孔径没有统计学差异，两种胶原/HA 组之间的 HA 含量也没有统计学差异。胶原/HA（MW6.5K）组的荧光强度在第 14、21 和 28 天增加，明显高于其他组。组织学免疫组化研究也得到了类似的结果。发现 CD31 染色的血管与 QD 荧光共定位，这些新形成的血管在胶原/HA（MW6.5K）组的第 14 天出现，并在第 21 和 28 天显著增加。
本研究表明，与长链 HA（MW220K）和仅胶原相比，短链 HA（MW6.5K）的胶原支架再血管化速度更快。用于研究支架血管生成的新动物模型的结果与免疫染色和组织学检查的常规方法相吻合。
