DEVELOPMENT OF STRONG AND MACROPOROUS BIOMATERIALS

描述(申请人提供)：随着世界人口老龄化，对生物材料的需求增加。磷酸钙骨水泥(CPC)具有良好的骨传导性和骨替代能力，具有广阔的临床应用前景，但其强度较低，只能用于非应力状态。文献检索发现，目前还没有关于CPC纤维增强的研究。在初步研究中，CPC增强的前景被显示为强度增加2到5倍，断裂韧性增加6倍，断裂功增加两个数量级。在本项目中，Aim 1将使用可吸收纤维来增强CPC，然后溶解并创建微处理器血管内长；将研究纤维长度、体积分数和纤维-基质界面的影响。目的研究可吸收纤维性能变化对复合材料性能的影响，并建立预测方程。在目标3中，将使用具有广泛性质范围的CPC矩阵来建立基质和复合材料性质之间的关系。将研究非刚性CPC、速溶CPC、流动性CPC和大孔CPC，确定基本结构-性能关系模型。目的4将研究新的方法来控制大孔形成率和定制种植体的强度历史。在CPC中将快吸收纤维和慢吸收纤维结合在一起，以获得较高的初始强度。然后，较快的纤维会溶解，并为骨骼内长出大孔，而较慢的纤维则提供较长时间的强度。将执行建模以将复合材料性能变化与每种纤维的性能变化相关联。在目标5中，可吸收网将用于CPC以增强强度，然后高度相互连接的大孔。研究了浸泡过程中网格厚度和强度变化的影响，并建立了预测方程。功能梯度多层植入物将使用网状物和纤维进行研究，以控制强度和大孔形成梯度。这些研究将：1)产生新型牙科和颅面修复复合材料，具有优异的强度、自固化能力、支架结构和被新骨吸收和替换的能力；(3)建立种植体的微观结构设计方法，以实现高强度和高韧性，具有量身定制的强度历史和大孔形成速率；(3)提供新的增强机制、基本的复合成分关系、预测模型和加工指南，为新一代生物材料奠定基础。

DESCRIPTION (provided by applicant): The need for biomaterials has increased as the world population ages. Calcium phosphate cements (CPC) are highly promising for wide clinical applications due to their osteoconductivity and bone replacement capability.Their low strength, however, limits CPC to only non-stress uses. A literature search revealed no study on fiber reinforcement of CPC. In preliminary studies, the promise for CPC reinforcement was shown with a 2- to 5-fold increase in strength, 6-fold increase in fracture toughness, and two orders of magnitude increase in work-of-fracture. In this project, Aim 1 will use absorbable fibers to strengthen CPC and then to dissolve and create microprocessor vascular ingrowth; the effects of fiber length, volume fraction and fiber-matrix interface will be studied. Aim 2vill study the effects of changes in the absorbable fiber properties on the composite properties, and establish predictive equations. In Aim 3, CPC matrices with wide property ranges will be used to establish the relationships between matrix and composite properties. Non-rigid CPC, fast-dissolution CPC, flow able CPC and macroporous CPC will be studied; models on fundamental structure-property relationships will be determined. Aim 4 will investigate novel methods to control the macropore formation rate and tailor the strength history of the implant. Faster-absorbable fibers and slow-absorbable fibers will be combined in CPC for a high initial strength. Then the faster fibers dissolve and create macropores for bony ingrowth, while the slow fibers provide longer-term strength. Modeling will be performed to relate the composite property change to that of each fiber. In Aim 5, absorbable meshes will be used in CPC for strength and then highly interconnected macropores. The effects of mesh thickness and strength changes in immersion will be investigated and predictive equations will be established. Functionally graded multilayer implants will be investigated using mesh and fibers for controlled strength and macropore formation gradient. These studies will: 1) Yield novel composites for Dental and craniofacial repairs with superior strength, self-setting ability, scaffold structures, and capability of resorption and replacement by new bone; (it) Establish microstructural design methods for implants to achieve high strength and toughness with tailored strength history and macropore formation rates; (iii) Provide new reinforcement mechanisms, fundamental composite-constituent relationships, predictive models, and processing guidance to form the basis for a new generation of biomaterials.