中文摘要：

基于分步凝胶化的快速成形工艺可实现纤维蛋白支架的成形：先借助明胶的低温凝胶化特性成形明胶纤维蛋白原混合材料支架，继而用凝血酶凝胶化支架中的纤维蛋白原，最后于37℃水溶液环境中将明胶从支架中溶出。凝胶化过程研究表明，凝血酶浓度同时影响了纤维蛋白凝胶化速度及最终的微观结构，明胶在凝胶化过程形成的微晶区域使其吸光度值持续缓慢下降。通过控制明胶凝胶化程度可得到液滴态、连续丝态、不稳定丝态等出丝形态，以连续丝态为参照确定了明胶成形的最佳温度区域。分步凝胶化成形工艺可制备二分支管道、网格立方等三维支架。扫描电镜观察发现支架具有典型纤维蛋白特征的纤维网络结构及纤维蛋白与明胶相互融合形成的带膜纤维网络结构。

英文摘要：

Fibrin is a promising tissue engineering scaffold material with excellent biocompatibility, while solid freeform fabrication is becoming an important technology for the fabrication of scaffolds with complex structure. Research on the solid fi＇eeform fabrication of fibrin can combine the advantages of both sides. A two-step gelatinization technology is presented for this end. Firstly rapid prototype a gelatin-fibrinogen hybrid scaffold in a low temperature environment, then put it in thrombin solution to catalyze fibrinogen into fibrin, lastly let the gelatin in the scaffold be dissolved in 37℃ water solution environment. Research on the gelation process shows that the thrombin concentration has influence on both gelation speed and final microstructure of fibrin, while microlite zones formed during the gelation process of gelatin makes its absorbance value keep declining slowly. Four filament status of gelatin are obtained corresponding to its gelatinization degrees, which includes droplet, continuous filament, unstable filament etc. An optimal temperature zone is identified for the solid freeform fabrication of gelatin. Scaffolds of various structures can be fabricated with two-step gelatinization technology＇, which includes grid-cubic, two-branch valve, etc. SEM observation of fibrin scaffolds shows both fiber network which is characteristic of fibrin and fiber network with membrane formed by the infiltration of gelatin into the fibrin network.