Self-complementary AAV2.5-BMP2-coated Femoral Allografts Mediated Superior Bone Healing Versus Live Autografts in Mice With Equivalent Biomechanics to Unfractured Femur
Self-complementary AAV2.5-BMP2-coated Femoral Allografts Mediated Superior Bone Healing Versus Live Autografts in Mice With Equivalent Biomechanics to Unfractured Femur
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DOI：
10.1038/mt.2010.294
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发表时间：
2011-08-01
影响因子：
12.4
通讯作者：
Schwarz, Edward M.
中科院分区：
文献类型：
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作者：
Yazici, Cemal;Takahata, Masahiko;Schwarz, Edward M.
用于治疗严重骨缺损的结构性同种异体移植物的生物整合成骨特性有限。尽管表达骨形态发生蛋白 2 (BMP2) 的离体组织工程构建体已在严重缺陷模型中表现出功效，但现成的非细胞方法尚未取得类似的成功，包括涂有冻干单链腺相关病毒 (ssAAV-BMP2) 的同种异体移植物。为了了解自我互补的 AAV 血清型 2.5 载体 (scAAV2.5-BMP2) 是否可以克服这个问题，我们在体外和小鼠股骨同种异体移植模型中进行了并排比较。尽管ssAAV-BMP2无法在培养物中诱导C3H10T1/2细胞的BMP2表达和分化，但scAAV2.5-BMP2转导导致剂量依赖性BMP2表达和碱性磷酸酶活性，并且体内转导效率提高了25倍。 6 周后，ssAAV-BMP2 涂层未能表现出任何显着效果。然而，所有涂有 10(10) scAAV2.5-BMP2 的同种异体移植物都形成了新的皮质壳，与活体自体移植物形成的皮质壳没有区别。此外，涂层同种异体移植物的吸收减少，导致移植物骨体积比自体移植物增加三倍。这导致了相对于同种异体移植物和自体移植物的生物力学优越性，以及与未骨折股骨相当的扭转刚度。总的来说，这些结果表明 scAAV2.5-BMP2 涂层克服了结构同种异体移植物的主要局限性，可用于治愈任何大小的关键缺陷。
Structural allografts used for critical bone defects have limited osteogenic properties for biointegration. Although ex vivo tissue-engineered constructs expressing bone morphogenetic protein-2 (BMP2) have demonstrated efficacy in critical defect models, similar success has not been achieved with off-the-shelf acellular approaches, including allografts coated with freeze-dried single-stranded adeno-associated virus (ssAAV-BMP2). To see whether the self-complementary AAV serotype 2.5 vector (scAAV2.5-BMP2) could overcome this, we performed side-by-side comparisons in vitro and in the murine femoral allograft model. Although ssAAV-BMP2 was unable to induce BMP2 expression and differentiation of C3H10T1/2 cells in culture, scAAV2.5-BMP2 transduction led to dose-dependent BMP2 expression and alkaline phosphatase activity, and displayed a 25-fold increased transduction efficiency in vivo. After 6 weeks, the ssAAV-BMP2 coating failed to demonstrate any significant effects. However, all allografts coated with 10(10) scAAV2.5-BMP2 formed a new cortical shell that was indistinguishable to that formed by live autografts. Additionally, coated allografts experienced reduced resorption resulting in a threefold increase in graft bone volume versus autograft. This led to biomechanical superiority versus both allografts and autografts, and equivalent torsional rigidity to unfractured femur. Collectively, these results demonstrate that scAAV2.5-BMP2 coating overcomes the major limitations of structural allografts, which can be used to heal critical defects of any size.