DESIGNED DEGRADABLE INTERBODY CAGES

描述（由申请人提供）：目前用于脊柱畸形矫正和椎间盘源性轴性背痛（伴或不伴神经根病）的金标准手术干预是节段性脊柱融合术。目前，美国每年进行超过25万例脊柱融合术。然而，目前的融合方法具有显著的缺点，包括下沉、应力遮挡以及不能直接递送骨形态发生蛋白（BMP）用于骨再生。我们建议开发可降解聚合物融合器，其设计具有足够的机械完整性，以承受手术植入和脊柱载荷，同时提供BMP的定向输送用于骨融合。具体而言，我们将创建和测试原型椎间可降解脊柱融合器，以满足这些承重和生物因子输送要求，方法是针对承重和定向渗透性要求计算优化器械设计，使用固体自由成型制造（SFF）技术用可降解聚合物制造融合器，并在尤卡坦小型猪脊柱融合模型中进行体内测试。我们假设，优化可降解脊柱椎间融合器以满足初始和中期载荷承载以及定向生物因子输送要求，将提供优于当前可降解融合器（由先前用于钛融合器的设计制成）的关节固定术。将通过以下3个特定目标对该总体设计假设进行检验：特定目标1：脊柱融合器的计算优化。具体目标2：器械制造和体外评价。具体目标3：在体内尤卡坦小型猪模型中测试融合性能。最终结果将验证所设计的可降解融合装置与常规设计相比是否提供了上级融合结果，更广泛地说，优化方法是否可以用于改善其他骨骼重建装置的性能。

DESCRIPTION (provided by applicant): The current gold standard surgical intervention for spinal deformity correction and for discogenic axial back pain with or without concomitant radiculopathy is a segmental spinal fusion. Currently, over 250,000 spine fusions are performed yearly in the US. However, current fusion approaches suffer from significant drawbacks including subsidence, stress shielding, and the inability to direct delivery of bone morphogenic protein (BMP) for bone regeneration. We propose to develop degradable polymeric fusion cages that are designed to have sufficient mechanical integrity for withstanding surgical implantation and spinal loads, while at the same time providing directed delivery of BMP for bone fusion. Specifically, we will create and test prototype interbody degradable spinal fusion cages to meet these load bearing and biofactor delivery requirements by computationally optimizing device design for both load carrying and directed permeability requirements, fabricating the cages from degradable polymer using Solid Free-Form Fabrication (SFF) techniques, and testing these in vivo in a Yucatan minipig spine fusion model. We hypothesize that optimizing degradable spine interbody fusion cages to meet both the initial and the intermediate- term load carry as well as directed biofactor delivery requirements will provide superior arthrodesis compared to current degradable cages fabricated from designs previously used for titanium cages. This global design hypothesis will be tested through the following 3 specific aims: Specific Aim 1: Computational Optimization of Spinal Fusion Cages. Specific Aim 2: Device Fabrication and In Vitro Evaluation. Specific Aim 3: Test Fusion Performance in an In Vivo Yucatan minipig Model. The end result will verify if the designed degradable fusion device provides superior fusion results compared to conventional designs, and more broadly, whether the optimization approach could be utilized to improve performance of other skeletal reconstruction devices.