Self-Assembly of Aligned Tissue-Engineered Annulus Fibrosus and Intervertebral Disc Composite Via Collagen Gel Contraction
Self-Assembly of Aligned Tissue-Engineered Annulus Fibrosus and Intervertebral Disc Composite Via Collagen Gel Contraction
复制标题
DOI：
10.1089/ten.tea.2009.0442
复制
发表时间：
2010-04-01
影响因子：
4.1
通讯作者：
Bonassar, Lawrence J.
中科院分区：
文献类型：
--
作者：
Bowles, Robby D.;Williams, Rebecca M.;Bonassar, Lawrence J.
许多软骨组织如椎间盘（IVD）显示出导致力学各向异性的异质胶原微结构。这些结构负责组织的机械功能，并调节嵌入这些组织内的细胞的细胞相互作用和代谢反应。使用接种有绵羊纤维环细胞的胶原凝胶，创建不同结构和异质性的构建体以模拟IVD的周向对齐。通过使用聚乙烯中心和藻酸盐中心围绕内边界收缩环形凝胶来诱导凝胶内的对齐，以产生复合工程化IVD。使用二次谐波发生显微镜测量胶原排列和异质性。将初始胶原蛋白密度从2.5 mg/mL降低至1 mg/mL产生了更大的结构收缩，导致培养后凝胶分别为原始面积的55%和6.2%。结果，与2.5 mg/mL凝胶相比，在环形1 mg/mL凝胶中发生更多对齐（p < 0.05）。这种对齐也产生在复合工程IVD与藻酸盐髓核。所得到的胶原对齐可以促进创建机械功能性组织工程化IVD所必需的进一步对齐的胶原发育。
Many cartilaginous tissues such as intervertebral disc (IVD) display a heterogeneous collagen microstructure that results in mechanical anisotropy. These structures are responsible for mechanical function of the tissue and regulate cellular interactions and metabolic responses of cells embedded within these tissues. Using collagen gels seeded with ovine annulus fibrosus cells, constructs of varying structure and heterogeneity were created to mimic the circumferential alignment of the IVD. Alignment was induced within gels by contracting annular gels around an inner boundary using both a polyethylene center and alginate center to create a composite engineered IVD. Collagen alignment and heterogeneity were measured using second harmonic generation microscopy. Decreasing initial collagen density from 2.5 mg/mL to 1 mg/mL produced greater contraction of constructs, resulting in gels that were 55% and 6.2% of the original area after culture, respectively. As a result, more alignment occurred in annular-shaped 1 mg/mL gels compared with 2.5 mg/mL gels (p < 0.05). This alignment was also produced in a composite-engineered IVD with alginate nucleus pulposus. The resulting collagen alignment could promote further aligned collagen development necessary for the creation of a mechanically functional tissue-engineered IVD.