DEVELOPMENT OF STRONG AND MACROPOROUS BIOMATERIALS

描述（由申请人提供）：随着世界人口老龄化，对生物材料的需求增加。磷酸钙骨水泥（CPC）因其良好的骨传导性和骨替代能力而具有广泛的临床应用前景，但其强度低，限制了CPC的非应力应用。文献检索显示没有关于CPC纤维增强的研究。在初步研究中，CPC增强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。在本项目中，Aim 1将使用可吸收纤维增强CPC，然后溶解并创建微处理器血管长入;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，将使用具有宽性能范围的CPC矩阵来建立矩阵和复合材料性能之间的关系。将研究非刚性CPC、快速溶解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将研究新的方法来控制大孔形成速率和定制植入物的强度历史。在CPC中结合吸收快的纤维和吸收慢的纤维以获得高的初始强度。然后，较快的纤维溶解并产生用于骨长入的大孔，而较慢的纤维提供较长期的强度。将进行建模，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，可吸收补片将用于CPC以增强强度，然后用于高度互连的大孔。将研究网格厚度和强度在浸没中的变化的影响，并建立预测方程。将使用网和纤维研究功能梯度多层植入物，以控制强度和大孔形成梯度。这些研究将：1）产生用于牙齿和颅面修复的新型复合材料，其具有上级强度、自固化能力、支架结构以及被新骨吸收和置换的能力;（it）建立用于植入物的微观结构设计方法，以实现具有定制强度历史和大孔形成速率的高强度和韧性;（iii）提供新的强化机制、基本的复合成分关系、预测模型和加工指导，以形成新一代生物材料的基础。

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.