Borde Brandon, Grunert Peter, Härtl Roger, Bonassar Lawrence J
Department of Biomedical Engineering, Cornell University, Ithaca, New York.
Department of Neurological Surgery, Weill Cornell Medical College, New York, New York.
J Biomed Mater Res A. 2015 Aug;103(8):2571-81. doi: 10.1002/jbm.a.35388. Epub 2014 Dec 29.
A herniated intervertebral disc often causes back pain when disc tissue is displaced through a damaged annulus fibrosus. Currently, the only methods available for annulus fibrosus repair involve mechanical closure of defect, which does little to address biological healing in the damaged tissue. Collagen hydrogels are injectable and have been used to repair annulus defects in vivo. In this study, high-density collagen hydrogels at 5, 10, and 15 mg/mL were used to repair defects made to intact rat caudal intervertebral discs in vitro. A group of gels at 15 mg/mL were also cross-linked with riboflavin at 0.03 mM, 0.07 mM, or 0.10 mM. These cross-linked, high-density collagen gels maintained their presence in the defect under loading and contributed positively to the mechanical response of damaged discs. Discs exhibited increases to 95% of undamaged effective equilibrium and instantaneous moduli as well as up to fourfold decreases in effective hydraulic permeability from the damaged discs. These data suggest that high-density collagen gels may be effective at restoring mechanical function of injured discs as well as potential vehicles for the delivery of biological agents such as cells or growth factors that may aid in the repair of the annulus fibrosus.
当椎间盘组织通过受损的纤维环移位时，椎间盘突出通常会导致背痛。目前，唯一可用于修复纤维环的方法是机械性闭合缺损，这对受损组织的生物愈合几乎没有作用。胶原蛋白水凝胶可注射，已被用于体内修复纤维环缺损。在本研究中，使用浓度为5、10和15mg/mL的高密度胶原蛋白水凝胶在体外修复完整大鼠尾椎椎间盘制造的缺损。一组浓度为15mg/mL的水凝胶还用0.03mM、0.07mM或0.10mM的核黄素进行交联。这些交联的高密度胶原蛋白凝胶在加载情况下能在缺损处保持存在，并对受损椎间盘的力学反应有积极贡献。椎间盘的有效平衡模量和瞬时模量增加到未受损时的95%，有效水力渗透率比受损椎间盘降低了四倍之多。这些数据表明，高密度胶原蛋白凝胶可能有效地恢复受损椎间盘的力学功能，并且可能是递送生物制剂（如细胞或生长因子）的潜在载体，这些生物制剂可能有助于纤维环的修复。
