Zhao Haiguang, Ma Lie, Zhou Jie, Mao Zhengwei, Gao Changyou, Shen Jiacong
Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Hangzhou 310027, People's Republic of China.
Biomed Mater. 2008 Mar;3(1):015001. doi: 10.1088/1748-6041/3/1/015001. Epub 2007 Dec 19.
The fast development of tissue engineering and regenerative medicine drives the old biomaterials, for example, fibrin glue, to find new applications in these areas. Aiming at developing a commercially available hydrogel for cell entrapment and delivery, in this study we optimized the fabrication and gelation conditions of fibrin gel. Fibrinogen was isolated from human plasma by a freeze-thaw circle. Gelation of the fibrinogen was accomplished by mixing with thrombin. Absorbance of the fibrinogen/thrombin mixture at 550 nm as a function of reaction time was monitored by UV-VIS spectroscopy. It was found that the clotting time is significantly influenced by the thrombin concentration and the temperature, while less influenced by the fibrinogen concentration. After freeze-drying, the fibrin gel was characterized by scanning electron microscopy (SEM), revealing fibrous microstructure. Thermal gravimetric analysis found that the degradation temperature of the crosslinked fibrin gel starts from 288 degrees C, which is about 30 degrees C higher than that of the fibrinogen. The hydrogel has an initial water-uptake ratio of approximately 50, decreased to 30-40 after incubation in water for 11 h depending on the thrombin concentration. The fibrin gels lost their weights in PBS very rapidly, while slowly in DMEM/fetal bovine serum and DMEM. In vitro cell culture found that human fibroblasts could normally proliferate in the fibrin gel with spreading morphology. In conclusion, the fibrin gel containing higher concentration of fibrinogen (20 mg ml(-1)) and thrombin (5 U ml(-1)) has suitable gelation time and handling properties, and thus is applicable as a delivery vehicle for cells such as fibroblasts.
组织工程和再生医学的快速发展促使诸如纤维蛋白胶等传统生物材料在这些领域寻找新的应用。本研究旨在开发一种可用于细胞包封和递送的商用凝胶，对纤维蛋白胶的制备和凝胶化条件进行了优化。通过冻融循环从人血浆中分离纤维蛋白原。将纤维蛋白原与凝血酶混合以完成凝胶化。通过紫外可见光谱监测纤维蛋白原/凝血酶混合物在550nm处的吸光度随反应时间的变化。结果发现，凝血时间受凝血酶浓度和温度的影响显著，而受纤维蛋白原浓度的影响较小。冻干后，通过扫描电子显微镜（SEM）对纤维蛋白胶进行表征，显示出纤维状微观结构。热重分析发现，交联纤维蛋白胶的降解温度从288℃开始，比纤维蛋白原高约30℃。该水凝胶的初始吸水率约为50，在水中孵育11小时后，根据凝血酶浓度降至30 - 40。纤维蛋白胶在PBS中失重很快，而在DMEM/胎牛血清和DMEM中失重较慢。体外细胞培养发现，人成纤维细胞能够在纤维蛋白胶中正常增殖并呈铺展形态。总之，含有较高浓度纤维蛋白原（20mg ml(-1)）和凝血酶（5U ml(-1)）的纤维蛋白胶具有合适的凝胶化时间和操作性能，因此可作为成纤维细胞等细胞的递送载体。
