Abstract：
Intervertebral disc (IVD) herniation is a leading cause of disability and lower back pain, causing enormous socioeconomic burdens. The standard of care for disc herniation is nucleotomy, which alleviates pain but does not repair the annulus fibrosus (AF) defect nor recover the biomechanical function of the disc. Existing bioadhesives for AF repair are limited by insufficient adhesion and significant mechanical and geometrical mismatch with the AF tissue, resulting in the recurrence of protrusion or detachment of bioadhesives. Here, we report a composite hydrogel sealant constructed from a composite of a three-dimensional (3D)-printed thermoplastic polyurethane (TPU) mesh and tough hydrogel. We tailored the fiber angle and volume fraction of the TPU mesh design to match the angle-ply structure and mechanical properties of native AF. Also, we proposed and tested three types of geometrical design of the composite hydrogel sealant to match the defect shape and size. Our results show that the sealant could mimic native AF in terms of the elastic modulus, flexural modulus, and fracture toughness and form strong adhesion with the human AF tissue. The bovine IVD tests show the effectiveness of the composite hydrogel sealant for AF repair and biomechanics recovery and for preventing herniation with its heightened stiffness and superior adhesion. By harnessing the combined capabilities of 3D printing and bioadhesives, these composite hydrogel sealants demonstrate promising potential for diverse applications in tissue repair and regeneration.
摘要：
椎间盘（IVD）突出是残疾和下背部疼痛的主要原因，造成巨大的社会经济负担。椎间盘突出症的护理标准是核切开术，可以减轻疼痛，但不能修复纤维环（AF）缺损，也不能恢复椎间盘的生物力学功能。用于AF修复的现有生物粘合剂受到粘附力不足以及与AF组织的显著机械和几何失配的限制。导致生物粘合剂的突出或脱离复发。这里,我们报告了一种由三维（3D）打印的热塑性聚氨酯（TPU）网和坚韧的水凝胶的复合材料构成的复合水凝胶密封剂。我们定制了TPU网设计的纤维角度和体积分数，以匹配天然AF的角度层结构和机械性能。此外，我们提出并测试了三种类型的复合水凝胶密封剂的几何设计，以匹配缺陷的形状和大小。我们的结果表明，密封剂可以模仿天然AF的弹性模量，弯曲模量,和断裂韧性，并与人体AF组织形成牢固的粘附。牛IVD测试表明复合水凝胶密封剂用于AF修复和生物力学恢复以及用于预防疝的有效性,其具有提高的刚度和优异的粘附性。通过利用3D打印和生物粘合剂的综合能力，这些复合水凝胶密封剂在组织修复和再生中显示出多种应用的潜力。
