Graded Bioactive Coatings for Implants

描述：本申请的目的是继续开发用于金属和陶瓷植入物的新型玻璃和微晶玻璃(羟基磷灰石)涂层。我们的长期目标是生产出与基材具有良好附着力和长期稳定性的“智能”生物活性涂层。植入材料是一个极端的挑战，因为它们必须满足许多相互冲突的要求。事实上，由于没有一种单一的材料可以满足所有这些要求，因此使用涂层变得至关重要。这类涂层提出了更多的材料挑战，因为它们需要在不影响其主要功能特性的情况下与基材结合。我们的研究表明，克服这一挑战的最有利策略是设计功能梯度(FGM)玻璃和微晶玻璃涂层。这是对当前商业涂层技术的重大改进，例如等离子喷涂，后者对涂层成分和微观结构的控制受到严重限制。分级设计还可以扩展到生物活性涂层的制造，为生长因子和药物提供局部输送平台，以鼓励涂层与其细胞和组织环境之间的积极和特定的相互作用，并提供治疗剂。然而，为了实现这一目标，需要开发新的涂层技术和玻璃组合物。这项继续拨款的具体目的是：1)测试可以开发新型玻璃系统以使用不同的加工技术在不同材料上制造可控梯度涂层的假设；2)测试可以结合新的涂层技术来制备具有微米到纳米尺度的结构和成分控制的梯度涂层的假设；3)测试氧化铝-氧化锆纳米复合材料具有足够的机械性能，特别是强度、韧性和抗疲劳性，用于牙科应用的假设，以及进一步测试所开发的涂层技术可以扩展到陶瓷结构材料使用的假设；以及4)在动物模型中验证这样的假设：与未涂层的对照相比，具有渐变涂层的植入物的骨-植入物的接触和结合可以显著增强。将新材料和加工技术与系统的机械和生物评估相结合，将使我们能够开发出具有前所未有的(但必要的)微观结构控制、优化的表面形貌和受控溶解行为的新涂层系列。这些涂层将适用于广泛的应用，从而大大改善植入物的生物集成。

DESCRIPTION: The intent of this application is to focus on the continued development of novel glass and glass-ceramic (hydroxyapatite) coatings for metallic and ceramic implants. Our long term goal is to produce "smart" bioactive coatings with excellent adhesion to the substrate and long term stability. Implant materials represent an extreme challenge since they must satisfy many conflicting requirements. Indeed, as no single material can meet all these requirements, the use of coatings becomes essential. Such coatings represent further material challenges in that they require bonding to the substrate without compromising their primary functional properties. Our research has shown that the most advantageous strategy to overcome this challenge is to design functionally graded (FGM) glass and glass-ceramic coatings. This is a significant improvement over current commercial coating techniques such as plasma spraying, where the control of the coating composition and microstructure is severely limited. The graded design can also be extended for the fabrication of bioactive coatings providing local delivery platform for growth factors and drugs, to encourage positive and specific interactions between the coatings and their cellular and tissue environment and to deliver therapeutic agents. Nevertheless, in order to achieve this objective novel coating techniques and glass compositions need to be developed. The Specific Aims of this grant continuation are: 1) To test the hypothesis that novel glass systems can be developed for the fabrication of controlled graded coatings on diverse materials using different processing techniques; 2) To test the hypothesis that novel coating techniques can be combined to prepare graded coatings with structural and compositional control over micro to nano size-scales; 3) To test the hypothesis that alumina-zirconia nanocomposites have adequate mechanical properties, specifically strength, toughness and fatigue resistance, to be used for Dental applications and further that the coating techniques developed can be extended for use with ceramic structural materials; and 4) To test the hypothesis that in an animal model, bone-implant contact and bonding can be markedly enhanced for implants with graded coatings versus uncoated controls. The combination of novel materials and processing techniques with systematic mechanical and biological evaluation will allow us to develop a new family of coatings with an unprecedented (but necessary) level of microstructural control, optimized surface morphologies and controlled dissolution behavior. These coatings will be adaptable to a wide range of applications permitting much improved biointegration of implants.