Department of Chemical and Petroleum Engineering, University of Kansas, Lawrence, KS, USA.
J Tissue Eng Regen Med. 2011 Aug;5(8):e179-87. doi: 10.1002/term.412. Epub 2011 Feb 25.
Tissue engineering strategies for the intervertebral disc (IVD) have traditionally focused either on the annulus fibrosus (AF) or the nucleus pulposus (NP) in isolation, or have simply compared AF cells and NP cells in identical culture conditions. Recently, others in the field have become aware of the advantage of combining the AF and NP into a more comprehensive strategy to address IVD tissue engineering, and have introduced biomimetic approaches to either AF or NP tissue engineering. Here, we introduced a new method for developing a biomimetic, cell-seeded IVD by electrospinning circumferentially-orientated polycaprolactone fibres (AF analogue), seeding them with cells (porcine chondrocytes) and then gelling a cell-agarose solution in the centre (NP analogue). Scanning electron microscopy images demonstrated a high degree of fibre alignment and, along with fluorescent actin staining, confirmed a preferred orientation of cells in the direction of the fibres. Viability assays and histology collectively demonstrated that cells were viable and well-distributed around the interface between the NP and AF regions. In addition, mechanical testing confirmed that the composite IVD scaffolds had higher moduli than the agarose hydrogels alone. As we enter the new decade and the fields of AF and NP tissue engineering begin to merge into a new interfacial and functional IVD tissue-engineering field, approaches such as the method presented here will serve as the foundation for continuously advancing technology that we ultimately endeavour to bring to the clinic for the treatment of patients severely afflicted by degenerative disc disease.
组织工程策略在传统上一直专注于纤维环（AF）或髓核（NP）中的一个，或者只是在相同的培养条件下比较 AF 细胞和 NP 细胞。最近，该领域的其他人已经意识到将 AF 和 NP 结合起来以更全面的策略来解决 IVD 组织工程的优势，并引入了仿生方法来进行 AF 或 NP 组织工程。在这里，我们介绍了一种通过静电纺丝法制备仿生、细胞接种的 IVD 的新方法，该方法是通过纺制周向取向的聚己内酯纤维（AF 类似物）、在纤维上接种细胞（猪软骨细胞），然后在中心凝固细胞-琼脂糖溶液（NP 类似物）。扫描电子显微镜图像显示出纤维高度的取向性，并且与荧光肌动蛋白染色一起，证实了细胞在纤维方向上的优先取向。活力测定和组织学共同证明细胞是存活的，并且在 NP 和 AF 区域之间的界面周围分布良好。此外，机械测试证实，复合材料 IVD 支架的模量高于单独的琼脂糖水凝胶。随着我们进入新的十年，AF 和 NP 组织工程领域开始融合成一个新的界面和功能的 IVD 组织工程领域，类似本文介绍的方法将为不断推进技术奠定基础，我们最终努力将其应用于临床，以治疗深受退行性椎间盘疾病困扰的患者。
