胶原蛋白-硫酸肝素生物支架在猪脑内的生物相容性分析

背景：胶原蛋白-硫酸肝素支架与人体神经内部结构十分相似。 目的：探讨胶原蛋白-硫酸肝素支架的体内生物相容性。 方法：将40只小猪随机均分为两组，以距离前囟中线旁开1.0 cm为穿刺点，利用骨穿针进行纵向穿刺，至脑蛛网膜下腔，感到落空感后，将骨穿针缓慢拔除，观察组植入胶原蛋白-硫酸肝素支架，对照组不予处置。术后1，3，7，14，30 d对两组脑组织进行透射电镜观察、细胞凋亡及Caspase-3蛋白表达检测。 结果与结论：早期电镜观察发现，观察组支架周边有个别脑组织神经元受损情况，并出现髓神经纤维脱髓鞘变化，支架与脑组织交界处及支架内部存在阳性Caspase-3蛋白，但在远离支架周边脑组织则无阳性蛋白表达。从术后1 d开始，观察组支架周边脑组织出现个别脑细胞凋亡情况，至术后30 d无明显凋亡细胞，对照组也表现出相似的变化，观察组术后1，3，7，14 d细胞凋亡数量高于对照组(P < 0.05)，两组术后 30 d细胞凋亡数量比较差异无显著性意义(P > 0.05)。两组Caspase-3蛋白表达均处于较低状态，且观察组术后3，7 d的Caspase-3蛋白表达高于对照组(P < 0.05)，其余时间点比较差异无显著性意义。表明胶原蛋白-硫酸肝素支架在猪脑内具有良好的生物相容性。中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程

Biocompatibility of a collagen-heparan sulfate scaffold in the porcine brain

BACKGROUND:The internal structures of the collagen-heparan sulfate scaffold and human nerve are very similar. OBJECTIVE:To explore the in vivo biocompatibility of collagen-heparin sulfate scaffold. METHODS:Forty pigs were randomly divided into two groups, 20 in each group: observation group and control group. Medullo-puncture needle was inserted 1.0 cm adjacent to the midline of anterior fontanelle into the subarachnoid space, and then removed gradually. Collagen-heparin sulfate scaffold was implanted into the observation group, and no treatment was given in the control group. Brain tissues were observed under transmission electron microscope, and cell apoptosis and Caspase-3 expression were detected at days 1, 3, 7, 14 and 30 after surgery. RESULTS AND CONCLUSION:Under the electron microscope, there were some damaged neurons in the observation group with the emergence of demyelination changes in the myelinated nerve fibers; positive  expression of Caspase-3 protein was found at the junction between the brain tissue and scaffold as well as within the scaffold, but no positive expression was found in the surrounding tissue. There was no cell apoptosis within 30 days after surgery except for individual apoptotic neurons both in the observation group and control group. The number of apoptotic cells in the observation group was higher than that in the control group at days 1, 3, 7, 14 days after surgery (P < 0.05), but there was no difference between the two groups at 30 days after surgery (P > 0.05). Caspase-3 protein expression was at a low state in the two groups, but the protein expression of Caspase-3 was higher in the observation group than the control group at days 3 and 7 after surgery (P < 0.05). These findings indicate that the collagen heparin sulfate scaffold has good biocompatibility in the porcine brain.