SBIR Phase I: Scalable Synthesis and Processing of Nanocrystalline Hydroxyapatite

这个小型企业创新研究第一阶段项目将开发生产适用于承重整形和牙科应用的纳米结构羟基磷灰石(HAP)生物材料的商业批量的工艺和控制。尽管羟基磷灰石的骨传导性在许多临床应用中引起了人们的兴趣，但由于物相纯度和均匀性差，传统的羟基磷灰石材料烧结性差，机械强度低，限制了其应用。在HAP的化学沉淀过程中，通过控制反应物的混合方法、颗粒回收和合成条件等物理过程，可以优化HAP的结晶度、化学计量比和颗粒形态以提高机械强度。经过机械强度优化的羟基磷灰石将是纳米晶，并具有更高的化学和热稳定性；这些特性将导致更好的烧结性和最小的颗粒生长。因此，将获得完全致密的纳米晶HAP单体，具有良好的化学均一性、微观结构均匀性、超细颗粒尺寸和最小缺陷尺寸。最终的结果是，制备的纳米晶羟基磷灰石整体将具有优异的抗压(900兆帕)和抗弯(200兆帕)强度以及断裂韧性(1.3兆帕1/2)。在商业上，这些纳米结构材料可以形成结构，并用于验证骨科植入物的实验模型。纳米羟基磷灰石将有助于更好的成骨细胞附着、增殖和矿化。

This Small Business Innovation Research Phase I project will develop processes and controls for producing commercial quantities of nanostructured hydroxyapatite (HAP) biomaterials suitable for load bearing orthopedic and dental applications. Though hydroxyapatite's osteoconductivity has generated interest in many clinical applications, conventionally processed hydroxyapatite materials have been limited by their poor sinterability and lack of mechanical strength attributed to poor phase purity and homogeneity. By controlling physical processes such as the method of mixing of reactants, particle recovery and synthesis conditions during the chemical precipitation of HAP, the crystallinity, stoichiometry and particle morphology of HAP will be optimized for mechanical strength. Hydroxyapatite optimized for mechanical strength will be nanocrystalline and possess increased chemical and thermal stability; these properties will lead to enhanced sinterability and minimal grain growth. As a result, fully dense, nanocrystalline HAP monoliths possessing superior chemical homogeneity, microstructural uniformity, ultrafine grain sizes and minimized flaw sizes will be achieved. In the final result, the nanocrystalline HAP monoliths produced will provide superior compressive (900 MPa) and bending (200 MPa) strengths as well as fracture toughness (1.3 MPam1/2).Commercially, these nanostructured materials can be formed into constructs and utilized in experimental models commonly employed to validate orthopedic implants.Nanostructured hydroxyapatites will contribute to better osteoblast attachment, proliferation and mineralization.