RESORBABLE BUFFERED INTERNAL FIXATION DEVICES

可吸收缓冲内固定装置

• 批准号: 2007027
• 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: 1997
• 资助国家: 美国
• 起止时间: 1997-08-16 至 1998-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2007027
• 关键词: biomaterial compatibility; biomaterial development /preparation; biotransformation; bone fracture; bone prosthesis; calcium carbonate; fracture fixation; glycolates; high performance liquid chromatography; laboratory rat; lactates; physiologic bone resorption; polymers; tissue /cell preparation

In approximately 8% of fracture reductions treated with resorbable polymeric devices fabricated from poly(lactide), poly(gycolide) or copolymers of lactic and glycolic acids, sterile abscesses are a complication requiring drainage and debridement. These abscesses are not immediately evident, forming seven to twenty weeks after surgery. Evidence is accumulating that these complications are associated with the acidic degradation products formed by in vivo hydrolysis of the polymers. A primary goal of our degradable bone repair system is to control the microenvironment of the implant by incorporating some buffering capacity in to the polymer which will neutralize the acidic products. However, while these polymers are suitable in terms of biocompatibility, they are frequently either too brittle or weak for safe clinical use in bone surgical applications. Thus, the development of a buffered fixture must address two issues simultaneously: effective neutralization of the acidic degradation products and reinforcement to maintain strength. The problems are of course related in that incorporation of neutralizing agents will further weaken the device. We have shown that calcium sales such as calcium carbonate are effective in controlling pH during fixture degradation. However, some weakening occurs. In the proposed Phase I project, we will determine the feasibility of compensating for his loss of strength by introducing unbuffered fibers of the same polymer (self reinforcement). In this regard, we introduce a novel approach to self reinforcement by placing the fibers under tension while being embedded in the matrix of buffered polymer. This new technique should result in improved mechanical properties. PROPOSED COMMERCIAL APPLICATION: 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 inflammatory responses to degradation. Our studies show that a buffered resorbable fixation device may ameliorate these responses. Development of the necessary strength will address the clinical demand for acceptable resorbable orthopedic materials.

在约8%的骨折复位治疗中， 由聚（丙交酯）、聚（乙交酯）或 乳酸和乙醇酸的共聚物，无菌乳液是一种 需要引流和清创的并发症。 这些女孩子是 不是立即明显的，在手术后7到20周形成。 越来越多的证据表明，这些并发症与 通过体内水解形成的酸性降解产物 聚合物 我们的可降解骨修复系统的主要目标是 控制植入物的微环境 缓冲能力的聚合物，这将中和酸性 产品. 然而，虽然这些聚合物在聚合物的性质方面是合适的， 由于生物相容性，它们通常太脆或太弱， 在骨外科应用中的临床应用。 因此，发展一个 缓冲夹具必须同时解决两个问题： 中和酸性降解产物， 保持力量。 这些问题当然是相互关联的， 加入中和剂将进一步削弱该装置。 我们已经表明，钙的销售，如碳酸钙， 在固定装置降解期间有效控制pH。 但也有 弱化发生。 在拟议的第一阶段项目中，我们将确定 他的力量损失的补偿的可行性， 相同聚合物的无缓冲纤维（自增强）。 在这 在这方面，我们介绍了一种新的方法，自我强化， 在张力下的纤维，同时被嵌入在基质中， 缓冲聚合物。 这项新技术将改善 力学性能 建议的商业应用：超过110万 在美国，每年有超过470.000例骨折需要内部治疗。 在愈合过程中固定骨折的固定装置。 尽管对可再吸收装置存在显著的临床需求， 现有产品尚未被广泛采用，因为 炎症反应降解。我们的研究表明， 缓冲的可吸收固定装置可以改善这些反应。 发展必要的力量将满足临床需求 可接受的可吸收骨科材料。