FRG: Organoapatite-Coated Titanium Foam: A Biohybrid for Skeletal Repair

FRG：有机磷灰石涂层钛泡沫：用于骨骼修复的生物混合物

• 批准号: 0108342
• 负责人: Samuel Stupp
• 金额: $ 57万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0108342&HistoricalAwards=false
• 关键词: FRG; Organoapatite; Coated; Titanium; Foam

This is a Focused Research Group(FRG) award co-funded by the Polymers, Ceramics and Metals Programs in the Division of Materials Research. Effective, rapid and permanent skeletal repair is one of the grand challenges of bioengineering and biomaterials research. Load-bearing bone repair is critical in cases of aging-related surgery, accident, disease, and trauma. Current metallic implant technology usually relies on solid implants with a porous coating to enhance cell attachment. Difficulties with stress-shielding and interface failure as well as prolonged recovery times however persist. Here, this Focused Research Group proposes to make a significant contribution in this area by creating a novel biohybrid implant material for bone repair. The biohybrid will consist of a biocompatible titanium foam with pores coated with bioactive organoapatite, in which a biological phase will be grown to provide a biomimetic system with improved strength, stiffness and attachment to the skeleton.%%%In the first stage, a fully porous titanium scaffold will be fabricated by a novel process based on the superplastic expansion of argon bubbles in a titanium matrix. In the second step, the inner and outer surfaces of the titanium scaffold will be coated with organoapatite, containing small quantities of organic molecules. Self-assembling molecules and supramolecular clusters will be used to bind the organoapatite to the metal surface. In the third step, bone growth will be induced by rotating the implant in an aqueous solution containing rat calvaria cells. In-vitro testing will assess ability to fully integrate bone into coated Ti foam and the influence of microstructure on mechanical properties and cell ingrowth will carefully studied. Each of the processing steps will be studied in detail, from which models will be developed to predict biologically and mechanically optimal biohybrids. The microstructure of the implant will be studied at each step with particular emphasis on (i) pores in the foamed materials (pore, size, volume fraction, shape and connectivity), (ii) coating morphology and microstructure in the biohybrid, and (iii) cell characteristics in the complete biohybrid. The mechanical properties of the implant will also be studied at each step, with emphasis on both the macroscopic scale (overall strength, stiffness, fatigue resistance) and the microscopic scale (metal/ceramic/bone interfaces). The experimental results will be validated using analytical and numerical mechanics models. The processing, microstructural and mechanical models will be integrate to allow for the design of an optimal biohybrid.

这是一个重点研究小组（FRG）奖，由材料研究部的聚合物，陶瓷和金属项目共同资助。 有效、快速、持久的骨修复是生物工程和生物材料研究的重大挑战之一。 承重骨修复在与年龄相关的手术、事故、疾病和创伤的情况下至关重要。 目前的金属植入物技术通常依赖于具有多孔涂层的固体植入物以增强细胞附着。 然而，应力屏蔽和界面失效以及恢复时间延长的困难仍然存在。 在这里，这个重点研究小组提出通过创造一种用于骨修复的新型生物混合植入材料在这一领域做出重大贡献。 这种生物混合体将由一种生物相容性的钛泡沫组成，泡沫上有一层涂有生物活性有机磷灰石的孔隙，其中将生长一种生物相，以提供一种具有改善的强度、刚度和与骨骼附着力的仿生系统。在第一阶段，将通过基于氩气泡在钛基质中的超塑性膨胀的新工艺制造全多孔钛支架。 在第二步中，钛支架的内表面和外表面将被涂上含有少量有机分子的有机磷灰石。 自组装分子和超分子簇将被用来将有机磷灰石结合到金属表面。 在第三步中，将通过在含有大鼠颅骨细胞的水溶液中旋转植入物来诱导骨生长。 体外试验将评估骨完全整合到涂层钛泡沫中的能力，并将仔细研究微观结构对力学性能和细胞长入的影响。 将详细研究每个处理步骤，从中开发模型以预测生物和机械最佳生物杂交体。 将在每个步骤研究植入物的微观结构，特别强调（i）泡沫材料中的孔（孔、尺寸、体积分数、形状和连通性），（ii）生物混合物中的涂层形态和微观结构，以及（iii）完整生物混合物中的细胞特征。 还将在每个步骤中研究植入物的机械性能，重点是宏观尺度（总体强度、刚度、抗疲劳性）和微观尺度（金属/陶瓷/骨界面）。 实验结果将使用分析和数值力学模型进行验证。 加工、微观结构和机械模型将被整合，以允许设计最佳的生物混合体。