This study sought to obtain a simple scaffold for annulus fibrosus (AF) repair or replacement using a combination of polyurethane (PU) reinforced with cellulose nanocrystals (CNCs). Composites containing up to 20 wt% CNCs were solvent casted and fabricated into ribbons and radially layered structures to be mechanically tested in tension, compression, creep, and relaxation. Tension and compression testing on swollen composite films and ringed structures, respectively, revealed that the PU 90/10 and PU 80/20 composites had elastic moduli most closely related to the natural AF tissues. Creep and relaxation revealed that the composite materials show a greater percentage of elastic response and longer relaxation times than natural intervertebral disc (IVD) tissues. It was shown that this approach leads to a scaffold that nearly mimics the mechanical properties of natural IVD tissues, while allowing fine tuning of these mechanical properties by varying CNC content and the ringed structure.

这项研究试图获得一种简单的支架，用于纤维环（AF）修复或置换，方法是使用纤维素纳米晶体（CNC）增强的聚氨酯（PU）组合。将含有20％（重量）CNCs的复合材料浇铸成溶剂，制成带状和径向分层的结构，以进行拉伸，压缩，蠕变和松弛的机械测试。分别对溶胀的复合膜和环状结构进行拉伸和压缩测试，结果表明PU 90/10和PU 80/20复合材料的弹性模量与天然AF组织最密切相关。蠕变和松弛表明，复合材料比天然椎间盘（IVD）组织显示出更大的弹性响应百分比和更长的松弛时间。