Polymeric Reinforcement of Degradable Bone Plates

可降解接骨板的聚合物增强材料

• 批准号: 6402333
• 负责人: DEBRA J TRANTOLO
• 金额: $ 10万
• 依托单位: CAMBRIDGE SCIENTIFIC, INC.
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6402333
• 关键词: biodegradable product; biomaterial compatibility; biomaterial development /preparation; biomechanics; bone plates; dicarboxylate; glycolates; hydroxyapatites; implant; lactates; medical implant science; polymers; tissue engineering; tissue support frame

Plates for internal fixation fabricated from biodegradable polymers may offer several advantages over metallic devices. They do not corrode; they may be constructed with moduli closer to that of normal bone than metal devices and thus, as a corollary, can reduce stress shielding; and finally, resorbability obviates the need for a second surgical procedure to remove the plate. Promising materials include the polylactides (PLA) and polylactide-co-glycolides (PLGA) that degrade via an autocatalytic route. However, when they are used in bone implants of significant size and thickness, this mode of degradation may lead to hollowing of the implant even though the overall dimensions appear unchanged. Catastrophic failure has been noted in experimental and clinical studies. If a resorbable bone plate can be made such that it contains an internal, supporting structure, the collapse may be prevented and the integrity of the osteosynthesis construct maintained. We propose the use of an unsaturated biodegradable polymer, polypropylene fumarate (PPF), that can be crosslinked in the presence of a host PLA biopolymer. This PPF reinforcement defines a three-dimensional network within the host PLA superstructure. The proposed Phase I project will address the feasibility of preparing a PLA bone plate reinforced with PPF using the hydrophobic crosslinker EDGMA (ethyleneglycol dimethacrylate) that can demonstrate in vitro a temporal mechanical profile that is commensurate with the mechanics of bone healing. The goal is to ameliorate the problems of plate deformation and mechanical collapse. PROPOSED COMMERCIAL APPLICATIONS: Of the more than 1.1 million fractures in the U.S. each year, greater than 470,000 require internal fixation devices to stabilize the fracture during the healing process. While there is significant clinical demand for resorbable devices, available products have not been widely adopted because of problems with dimensional stability. A reinforced, but still resorbable, fixation device that can ameliorate tendencies of plate deformation would address the clinical demand for resorbable orthopedic fixtures.

由可生物降解聚合物制成的内固定板与金属器械相比具有几个优点。它们不会腐蚀;它们可以被构造成具有比金属装置更接近于正常骨的模量，因此，作为必然结果，可以减少应力遮挡;最后，可再吸收性消除了移除板的第二外科手术的需要。有前途的材料包括聚乳酸（PLA）和聚乳酸-共-乙交酯（PLGA），通过自催化途径降解。然而，当它们用于较大尺寸和厚度的骨植入物时，这种降解模式可能导致植入物中空，即使整体尺寸看起来没有变化。在实验和临床研究中已经注意到灾难性的失败。如果可再吸收骨板可以制成包含内部支撑结构，则可以防止塌陷并保持骨接合构造的完整性。我们建议使用一种不饱和的可生物降解的聚合物，聚丙烯富马酸酯（PPF），它可以在宿主PLA生物聚合物的存在下交联。这种PPF加固在主体PLA上部结构内定义了一个三维网络。拟定的I期项目将讨论使用疏水交联剂EDGMA（乙二醇二甲基丙烯酸酯）制备PPF增强PLA接骨板的可行性，该接骨板可在体外证明与骨愈合力学相当的时间力学特征。目的是改善板块变形和机械塌陷问题。拟议的商业应用：在美国每年超过110万例骨折中，超过470，000例需要内固定器械在愈合过程中稳定骨折。虽然对可吸收装置有显著的临床需求，但由于尺寸稳定性问题，现有产品尚未被广泛采用。一种加强的，但仍然可吸收的，可以改善接骨板变形趋势的固定装置将满足对可吸收骨科固定装置的临床需求。