不同左旋聚乳酸支架微结构对心源干细胞增殖、分化的影响

Effects of different L-polylactic acid scaffold microstructures on proliferation and differentiation of cardiogenic stem cells

目的探讨不同空间微结构的左旋聚乳酸(PLLA)支架材料对心源干细胞增殖、分化的作用,筛选出性能优异的PLLA支架微结构。方法将三种不同微结构[层状结构(LS)、球体结构(MS)、纳米纤维结构(NS)]的PLLA支架各56个经酒精及紫外线消毒灭菌后,分别置入96孔板中,随后在96孔板种植相同数量的心源性干细胞,三种材料支架互相对照。采用MTT法检测细胞活力;取培养1周的三种微结构材料行共焦显微镜检测及扫描电镜检测,观察干细胞的增殖、分化情况。结果三种微结构材料支架均能促进心源性干细胞的增殖,从第48 h开始,细胞在NS中增殖速度最快,其次为MS,最后为LS,两两组间比较差异均有统计学意义(P<0.05);三种材料的单位有效接触面积内吸光度随培养时间增长而增加,并且两相邻时间点的增殖差异有统计学意义(P<0.05)。结论三种微结构均能促进干细胞的增殖、分化,其中纳米纤维结构效果最优,可作为心肌组织工程研究的优先选择。

Objective To investigate the effects of different spatial microstructures of L-polulactic acid(PLLA)scaffolds on proliferation and differentiation of cardiac stem cells,and to screen out the excellent PLLA scaffolds.Methods Fifty-six PLLA scaffolds with three different microstructures(layered structure(LS),spherical structure(MS),and nanofiber structure(NS))were sterilized by alcohol and ultraviolet radiation,and then placed in 96-well plates.The same number of cardiogenic stem cells were implanted in those plates.The three scaffolds were compared with each other.MTT assay was used to detect cell viability.Confocal microscopy and scanning electron microscopy were used to observe the growth and differentiation of the stem cells.Results All the three scaffolds could promote proliferation of the cardiogenic stem cells.Starting at 48 h,proliferation rate of cells in NS was the fastest,followed by MS and LS.There was significant difference between the two groups(P<0.05).The unit effective contact area absorbance of the three scaffolds increased over culture time,and the proliferation difference between the two adjacent time points was also statistically significant(P<0.05).Conclusion All three microstructures can promote the proliferation and differentiation of cardiogenic stem cells.Among them,nanofibers have the best effect and can be used as a preferred choice for myocardial tissue engineering research.