University of Wisconsin-Madison, Madison, Wisconsin, USA.
Arthroscopy. 2009 Dec;25(12):1427-34.e1. doi: 10.1016/j.arthro.2009.06.008. Epub 2009 Nov 6.
Our purpose was to determine whether a bioresorbable interference screw coated with a hydroxyapatite-based mineral layer designed to release an engineered peptide growth factor (linkBMP-2 [where "BMP-2" indicates bone morphogenetic protein 2]) improved tendon-bone healing compared with a screw without coating.
Tagged linkBMP-2 peptides were used to quantify binding efficiency and release kinetics on 9 mineral-coated BIORCI screws (Smith & Nephew, Andover, MA). Fourteen mature female sheep were used in this study. In each of the 14 sheep, each stifle was randomized to either receive a linkBMP-2-coated or uncoated interference screw (n = 14 per treatment). The sheep were euthanized at 6 weeks after surgery. Eight sheep were subjected to biomechanical testing for peak load at failure and stiffness, and six sheep were used for histologic analysis according to a semiquantitative scoring scale.
The linkBMP-2 molecule bound efficiently to the surface of mineral-coated interference screws. Over 80% of the initially bound linkBMP-2 was released during a 6-week time frame in vitro. Peak load at failure in the linkBMP-2-coated interference screw group (mean +/- SD, 449.3 +/- 84.7 N) was not significantly different from that in the uncoated group (421.0 +/- 61.8 N) (P = .22). Stiffness in the linkBMP-2-coated interference screw group (157.3 +/- 39.6 N/mm) was not significantly different from that in the uncoated group (140.6 +/- 20.3 N/mm) (P = .12). Histologic analysis showed that the tendons in the linkBMP-2-coated interference screw group had higher scores (better) than the uncoated group. In the linkBMP-2-coated interference screw group, mesenchymal cells were present at the interface between screw and tendon, whereas these cells were not present in the uncoated group.
We found that linkBMP-2 can be bound onto a mineral-coated BIORCI interference screw surface and subsequently released from the screw surface in a sustained manner. The histologic result of this study showed that the linkBMP-2-coated interference screw significantly improved the histologic scores of early tendon-bone healing in this sheep model.
This linkBMP-2 coating material may improve early tendon/ligament fixation.
我们的目的是确定一种涂有羟基磷灰石基矿物质层的可生物吸收的干扰螺钉,其设计目的是释放一种工程肽生长因子(链接 BMP-2[其中“BMP-2”表示骨形态发生蛋白 2]),与未涂层的螺钉相比,是否能改善肌腱-骨愈合。
使用标记的链接 BMP-2 肽来定量 9 个涂有 BIORCI 螺钉(Smith & Nephew,Andover,MA)的结合效率和释放动力学。这项研究使用了 14 只成熟雌性绵羊。在这 14 只绵羊中,每只膝关节均随机接受链接 BMP-2 涂层或未涂层的干扰螺钉(每组 14 只)。手术后 6 周,对 14 只绵羊进行安乐死。8 只绵羊用于进行失效峰值负载和刚度的生物力学测试,6 只绵羊用于根据半定量评分标准进行组织学分析。
链接 BMP-2 分子有效地结合在矿物质涂层的干扰螺钉表面。在体外 6 周的时间内,超过 80%的初始结合的链接 BMP-2 被释放。链接 BMP-2 涂层干扰螺钉组的失效峰值负载(平均值 +/- SD,449.3 +/- 84.7 N)与未涂层组(421.0 +/- 61.8 N)无显著差异(P =.22)。链接 BMP-2 涂层干扰螺钉组的刚度(157.3 +/- 39.6 N/mm)与未涂层组(140.6 +/- 20.3 N/mm)无显著差异(P =.12)。组织学分析显示,链接 BMP-2 涂层干扰螺钉组的肌腱评分(更好)高于未涂层组。在链接 BMP-2 涂层干扰螺钉组中,在螺钉和肌腱之间的界面处存在间充质细胞,而在未涂层组中则不存在这些细胞。
我们发现链接 BMP-2 可以结合到 BIORCI 干扰螺钉的矿物质涂层表面,并随后以持续的方式从螺钉表面释放。这项研究的组织学结果表明,在这种绵羊模型中,链接 BMP-2 涂层的干扰螺钉显著改善了早期肌腱-骨愈合的组织学评分。
这种链接 BMP-2 涂层材料可能会改善早期肌腱/韧带固定。