Development of SMP's for Cardiovascular Use

用于心血管用途的 SMP 的开发

• 批准号: 7140401
• 负责人: ROBIN SHANDAS
• 金额: $ 17.55万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7140401
• 关键词: bioengineering /biomedical engineering; biomaterial compatibility; biomaterial development /preparation; biomaterial evaluation; biomaterial interface interaction; biomechanics; biotechnology; blood vessel prosthesis; cardiovascular prosthesis; medical implant science; molecular shape; physical property; polymers; prosthetic heart valve; surgery material /equipment

DESCRIPTION (provided by applicant): Minimally invasive surgical techniques to implant cardiovascular devices for treatment of a variety of valvular, vascular and extra-vascular complications are increasingly exploited to improve patient outcomes, and reduce morbidity and cost. Originally based on simple metals, these devices are now becoming more sophisticated through the use of precisely engineered materials such as metal bimorphs (shape memory alloys) and new polymer structures. Polymers, in particular, exhibit significant advantages in these applications over metals and metal alloys, including ease of surface modification that enhances biocompatibility, greater mechanical flexibility to more accurately simulate native mechanical behavior, and availability of a wide variety of base structural configurations. Manipulation of polymers to produce shape memory characteristics is the most recent evolution, which due to their high degree of shape recoverability (order of magnitude greater than metal alloys) promises significantly greater freedom in designing minimally invasive cardiovascular devices. However, several substantial challenges preclude reliable and direct applications of shape memory polymers (SMPs) as innovative biomaterials for surgical implants. The goal of this project is to remove this limitation in the SMP design process by explicitly quantifying the thermomechanical properties of one promising type of SMP, and infusing this information into a commercially available finite element model (ABAQUS). This will provide designers of cardiovascular devices who wish to use SMPs with two enhancements required to enable exploitation of SMP biomaterials in future surgical devices: (1) new SMP engineering benchmarking characteristics required for rational design and proof-of-concept for SMP-based devices, and (2) a powerful a priori evaluation tool to refine and test device designs prior to fabrication. The model will then be exercised to produce two increasingly complex prototype devices: a vascular stent with significantly greater shape recoverability than currently available using metal shape memory alloys, and a prosthetic heart valve.

描述（由申请人提供）： 越来越多地利用了植入多种瓣膜，血管和血管外并发症来治疗多种瓣膜，血管和血管外并发症的最低侵入性手术技术，以改善患者的结果，并降低发病率和成本。这些设备最初是基于简单的金属，现在通过使用精确设计的材料（例如金属双层（形状内存合金））和新的聚合物结构而变得越来越复杂。尤其是聚合物在这些应用中比金属和金属合金具有显着优势，包括易于表面修饰，可增强生物相容性，更大的机械灵活性以更准确地模拟天然的机械行为以及各种基础结构构型的可用性。对聚合物产生形状记忆特性的操纵是最新的进化，由于它们的高度可恢复性（比金属合金大的数量级）有望在设计最小侵入性的心血管设备方面明显更大的自由度。然而，一些重大的挑战排除了形状记忆聚合物（SMP）作为手术植入物的创新生物材料的可靠和直接应用。该项目的目的是通过明确量化一种有希望的SMP类型的热力学特性，然后将此信息注入市售有限元模型（ABAQUS），从而消除SMP设计过程中的这一限制。这将为希望使用SMP的心血管设备的设计师提供两种增强功能，以实现未来的手术设备中SMP生物材料的开发：（1）新的SMP工程基准测试基准测试特征，用于基于SMP的设备的理性设计和概念证明的特征，以及（2）强大的先验评估工具以培养先验和测试设备设计。然后，该模型将进行生产，以生成两个日益复杂的原型设备：一种比使用金属形状记忆合金和假肢心脏阀相比，具有明显可恢复性的血管支架。