牛肌腱冻干脱细胞支架的生物力学特性

Biomechanical properties of a decellularized scaffold of lyophilized bovine tendon

背景:目前的脱细胞方法在去除细胞的同时对细胞外基质存在一定的损伤,降低了脱细胞支架的生物力学性能。目的:分析冻干牛肌腱脱细胞支架的生物力学特性。方法:取新鲜小牛趾伸屈肌腱,去除小牛肌腱表面的滑膜、腱膜及软组织,双蒸水冲洗干净后低压冻干,通过物理方法制备肌腱纤维束60个,随机均分为两组,实验组于无菌操作下置入丝氨酸蛋白酶抑制剂,室温下持续24 h,无菌PBS冲洗后,再移入低浓度胰酶+乙醇混合溶液中,在不破坏细胞外基质的情况下去除细胞壁,室温下持续5 h,再将纤维束移入脱氧核糖核酸酶溶液中持续5 h,最后将已完成脱细胞步骤的支架使用PBS冲洗48 h,无菌室内室温下干燥;对照组不做处置。检测两组材料的弹性模量、耐久性及最大应力。结果与结论:两组耐久性相似,但实验组在相同位移处的应力小于对照组;两组弹性模量比较差异无显著性意义,但实验组最大应力低于对照组(P<0.01)。说明冻干脱细胞支架能够在一定程度上模仿牛肌腱的生物力学功能。

BACKGROUND：Current decelularized methods have the certain damage to the extracelular matrix and reduce the biomechanical properties of acelular scaffolds. OBJECTIVE：To explore the biomechanical properties of decelularized scaffold of lyophilized bovine tendon. METHODS：Sixty lyophilized fiber bundles from fresh flexion tendon of calf toes were randomly divided into two groups： control group and experimental group. In the experimental group, serine protease inhibitors were placed asepticaly for 24 hours at room temperature, then the samples were rinsed with PBS and transferred to the low concentration of trypsin＋ethanol mixed solution to remove the cel wal without destruction of the extracelular matrix at room temperature for 5 hours; after that, the fiber bundles were cultured in DNA enzyme solution for 5 hours, finaly the acelular scaffold was completed and rinsed with PBS for 48 hours and dried at room temperature in sterile room. No treatment was done in the control group. Modulus of elasticity, durability and maximum stress were determined in the two groups. RESULTS AND CONCLUSION：Similar elastic modulus and durability were found in the two groups, but the maximum stress in the experimental group was significantly lower than that in the control group （P 〈 0.01）. These findings indicate that the lyophilized acelular tendon fibers can mimic the biological function of bovine tendon fibers to a certain extent.