DEVELOPMENT OF STRONG AND MACROPOROUS BIOMATERIALS

描述（由申请人提供）：随着世界人口老龄化，对生物材料的需求有所增加。磷酸钙骨水泥具有良好的骨导电性和骨替代能力，具有广泛的临床应用前景。然而，它们的低强度限制了CPC仅用于非应力用途。文献检索未发现对CPC纤维增强的研究。在初步研究中，CPC加固的前景显示出强度增加2至5倍，断裂韧性增加6倍，断裂功增加两个数量级。在这个项目中，Aim 1将使用可吸收纤维来加强CPC，然后溶解并产生微血管长入；研究了纤维长度、体积分数和纤维-基体界面对复合材料性能的影响。目的研究可吸收纤维性能的变化对复合材料性能的影响，并建立预测方程。在Aim 3中，具有广泛性质范围的CPC矩阵将用于建立矩阵和复合材料性质之间的关系。研究了非刚性CPC、快溶CPC、可流动CPC和大孔CPC；将确定基本结构-性质关系的模型。目的4将研究控制大孔形成速率和定制种植体强度历史的新方法。快速吸收纤维和缓慢吸收纤维将在CPC中组合，以获得较高的初始强度。然后，较快的纤维溶解并形成大孔以促进骨骼生长，而较慢的纤维则提供长期的强度。将执行建模以将复合材料属性变化与每个纤维的属性变化联系起来。在Aim 5中，可吸收的网格将用于CPC的强度，然后高度互联的大孔。研究了网格厚度和强度变化对浸没过程的影响，建立了预测方程。功能梯度多层植入物将研究使用网格和纤维来控制强度和大孔形成梯度。这些研究将：1)为牙齿和颅面修复提供新型复合材料，具有优越的强度、自固定能力、支架结构、吸收和新骨替代能力；(i)建立植入物的微观结构设计方法，通过定制强度历史和大孔形成速率实现高强度和高韧性；（iii）提供新的强化机制、基本复合成分关系、预测模型和加工指导，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.