背景:与通常的合成纤维相比,蚕丝力学性能好,又具有一定的延展性,是制作组织工程韧带/肌腱的良好支架材料,但蚕丝丝素纤维降解速度缓慢,难以与组织再生速率相匹配. 目的:分析蚕丝-聚乳酸-羟基乙酸共聚物编织绳状支架的力学性能及其与骨髓间充质干细胞体外共培养的细胞相容性. 方法:通过捻拧编织蚕丝-聚乳酸-羟基乙酸共聚物细丝混合支架,并以纤维连接蛋白作表面修饰,检测支架的力学性能.将兔骨髓间充质干细胞种植在蚕丝-聚乳酸-羟基乙酸共聚物细丝混合支架上进行体外共培养,观察细胞与支架复合生长、基质形成,以及细胞与支架结合的情况. 结果与结论:蚕丝-聚乳酸-羟基乙酸共聚物混合编织支架呈乳白色,质地均匀,韧性强,为螺旋上升的绳索状,直径为2.3 mm.支架材料的最大负荷、拉伸强度、断点伸长率、弹性模量分别为(315.06±30.77) N、(75.83±7.46) MPa、(61.39±7.26)%、(213.58±23.45) MPa.扫描电镜观察显示,骨髓间充质干细胞贴附于支架表面生长,增殖良好,细胞大多呈梭形,伸出伪足匍匐于材料的表面,形态较佳,伸展良好,呈立体状生长,并分泌基质.表明蚕丝-聚乳酸-羟基乙酸共聚物编织绳状支架具有良好的机械性能及细胞相容性.
BACKGROUND:Compared with the usual synthetic fibers, silk has better mechanical properties with a certain degree of ductility, which is a good scaffold material for construction of tissue engineered ligament/tendon. The degradation speed of silk fibroin fibers, however, is too low to correspond to tissue regeneration rate. OBJECTIVE:To evaluate the mechanical property of a rope-shaped scaffold braided by silk-poly(lactic-co-glycolic acid) and its cytocompatibility with rabbit bone marrow mesenchymal stem cel s. METHODS:Firstly, the hybrid rope-shaped silk-poly(lactic-co-glycolic acid) scaffold was prepared by twisting weave using a mixture of silkworm silk fibroin fiber and PLGA filament, and then modified by fibronectin. Secondly, rabbit bone marrow mesenchymal stem cel s were isolated and proliferated in vitro. Then, they were seeded on the surface of the scaffold. The situation of cel growth, matrix formation, as wel as the combination of cel s and scaffold was observed under an inverted phase contrast microscope and scanning electron microscopy. RESULTS AND CONCLUSION:The appearance of the scaffold braided by silk-poly(lactic-co-glycolic acid) was milky white, spiral rope-like, and homogeneous with a strong toughness. The diameter of the scaffold was 2.3 mm. The maximum load, tensile strength, breakpoints elongation rates, and elastic modulus of the scaffold were (315.06±30.77) N, (75.83±7.46) MPa, (61.39±7.26)%, (213.58±23.45) MPa, respectively. Scanning electron microscopy observation revealed that rabbit bone marrow mesenchymal stem cel s grew and adhered wel on the scaffold surface. Most of the bone marrow mesenchymal stem cel s showed spindle-shaped with good stretch, and they grew in three dimensions. Moreover, the bone marrow mesenchymal stem cel s secreted rich cel matrix on the surface of the scaffold braided by silk-poly(lactic-co-glycolic acid). In short, the scaffold braided by silk-poly(lactic-co-glycolic acid) has good biomechanical properties and