Material properties in unconfined compression of human nucleus pulposus, injectable hyaluronic acid-based hydrogels and tissue engineering scaffolds
Material properties in unconfined compression of human nucleus pulposus, injectable hyaluronic acid-based hydrogels and tissue engineering scaffolds
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DOI：
10.1007/s00586-007-0443-6
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发表时间：
2007-11-01
影响因子：
2.8
通讯作者：
Elliott, Dawn M.
中科院分区：
文献类型：
--
作者：
Cloyd, Jordan M.;Malhotra, Neil R.;Elliott, Dawn M.
与退行性椎间盘疾病相关的下背痛的手术治疗通常包括椎间盘切除术和脊柱融合术。虽然手术干预可以提供短期的疼痛缓解，但它会导致脊柱生物力学的改变，并可能导致相邻节段的进一步退行性变化。目前正在研究的一种非融合技术是通过可注射水凝胶或组织工程构建体的髓核（NP）支持。这两种方法的主要挑战是模仿天然NP的机械性能。在这里，我们采用无侧限压缩测试配置来评估脚趾区域和线性区域模量和泊松比，NP替换的关键功能参数。人NP，实验生物相容性水凝胶配方组成的透明质酸（HA），PEG-g-壳聚糖，和明胶，和传统的藻酸盐和琼脂糖凝胶进行了研究，作为可注射的NP替代品或组织工程支架。测试包括5%应变增量的应力松弛实验，随后是5分钟松弛期，总应变为25%。人NP的平均线性区域模量为5.39 +/-2.56 kPa，泊松比为0.62 +/-0.15。弹性模量和泊松比是评价植入材料和支架设计的重要参数。合成的基于HA的水凝胶很好地接近NP，并且可以用作合适的NP植入材料。
Surgical treatment for lower back pain related to degenerative disc disease commonly includes discectomy and spinal fusion. While surgical intervention may provide short-term pain relief, it results in altered biomechanics of the spine and may lead to further degenerative changes in adjacent segments. One non-fusion technique currently being investigated is nucleus pulposus (NP) support via either an injectable hydrogel or tissue engineered construct. A major challenge for either approach is to mimic the mechanical properties of native NP. Here we adopt an unconfined compression testing configuration to assess toe-region and linear-region modulus and Poisson's ratio, key functional parameters for NP replacement. Human NP, experimental biocompatible hydrogel formulations composed of hyaluronic acid (HA), PEG-g-chitosan, and gelatin, and conventional alginate and agarose gels were investigated as injectable NP replacements or tissue engineering scaffolds. Testing consisted of a stress-relaxation experiment of 5% strain increments followed by 5-min relaxation periods to a total of 25% strain. Human NP had an average linear-region modulus of 5.39 +/- 2.56 kPa and a Poisson's ratio of 0.62 +/- 0.15. The modulus and Poisson's ratio are important parameters for evaluating the design of implant materials and scaffolds. The synthetic HA-based hydrogels approximated NP well and may serve as suitable NP implant materials.