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Ceramic scaffolds with engineered topography and chemistry

具有工程形貌和化学特性的陶瓷支架

基本信息

批准号：
8590115
负责人：
Isabelle L Denry
金额：
$ 37.37万
依托单位：
UNIVERSITY OF IOWA
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-02-01 至 2017-01-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The research proposed in this application is directed at developing novel ceramic scaffolds that are bioresorbable, bioactive, osteoconductive and exhibit high strength. These goals will be achieved through stepwise engineering of the ceramic microstructure, scaffold architecture, micro and nanotopography and surface chemistry. The rationale is that there is currently no synthetic scaffold material that is bioactive, resorbable and exhibits biologically compatible compressive strength. We will first investigate the crystallization kinetics and mechanical properties of sintered niobium- doped fluorapatite (FAp) ceramics with the aim of developing a highly crystalline ceramic with nanosized FAp crystals (Aim 1). We will select the best composition with niobium additions that will induce phase separation, lead to the crystallization of nanosized crystals and high crystallinity. We will then prepare FAp ceramic scaffolds using a carefully engineered approach that combines a pre-coating step, a glazing step and a chemical etching step (Aim 2). We postulate that optimization of the scaffold architecture will lead to superior mechanical properties and that the chemical etching step will promote a complex three-dimensional surface micro and nanotopography later stimulating contact osteogenesis. The effect of ion-exchange on surface chemistry, solubility and bioactivity of the scaffolds will be tested in Aim 3. The overall rationale is that strontium substitution in the apatite structure will increase solubility and bioactivity. Finally, the resorption and bone regeneration ability of the scaffolds will be tested in vivo using a rat calvarial critical defect model and a combination of state of the art in vivo micro-computed tomography and histopathology (Aim 4). The hypotheses tested are that the surface chemistry and topography of the scaffolds will enhance bone regeneration and that the resorption rate will be compatible with the rate of bone regeneration.

描述（由申请人提供）：本申请中提出的研究旨在开发具有生物可吸收性、生物活性、骨传导性和高强度的新型陶瓷支架。这些目标将通过陶瓷微结构、支架结构、微米和纳米形貌以及表面化学的逐步工程化来实现。基本原理是目前没有生物活性的、可吸收的并且表现出生物相容性抗压强度的合成支架材料。我们将首先研究烧结的铌掺杂的氟磷灰石（FAp）陶瓷的结晶动力学和机械性能，目的是开发具有纳米尺寸的FAp晶体的高度结晶的陶瓷（目的1）。我们将选择最佳的组合物与铌添加剂，将诱导相分离，导致纳米尺寸的晶体和高结晶度的结晶。然后，我们将使用精心设计的方法制备FAp陶瓷支架，该方法结合了预涂层步骤，上釉步骤和化学蚀刻步骤（目标2）。我们假设支架结构的优化将导致上级机械性能，并且化学蚀刻步骤将促进复杂的三维表面微观和纳米形貌，随后刺激接触成骨。目标3将测试离子交换对支架表面化学、溶解度和生物活性的影响。总体原理是磷灰石结构中的锶取代将增加溶解度和生物活性。最后，将使用大鼠颅骨临界缺损模型和最新技术水平的体内显微计算机断层扫描和组织病理学的组合在体内测试支架的再吸收和骨再生能力（目的4）。所测试的假设是支架的表面化学和形貌将增强骨再生，并且再吸收速率将与骨再生速率相容。