Combinatorial Metal Oxide Substrates to Enhance Osteogenic Stem Cell Functions

描述（由申请人提供）：该项目的总体目标是为基于组合材料科学的生物材料筛选策略奠定基础。这种方法将为衬底提供一系列表面性质和组成的细微变化。这些新型材料配方的功效将在体外通过细胞培养模型和对生物材料元素组成的表面化学和地形对间充质干细胞（MSC）分化和与新骨形成相关的功能的影响进行系统的研究来确定。中心假设是材料底物的金属氧化物表面调节吸附蛋白质的类型、分布和构象，这些蛋白质直接和调节随后与新组织形成相关的细胞相互作用和功能。具体目标1：开发基于钛的金属氧化物衬底，其中包含三种其他金属的梯度，用作植入材料。假设，等离子体增强化学气相沉积退火，将产生浓度梯度的变厚度薄膜溅射到Ti衬底上。特异性目标2：确定选定的血清和/或ECM粘附蛋白的类型、分布和构象，如I型胶原蛋白、纤维连接蛋白、层粘连蛋白和玻璃体连接蛋白，吸附在与特异性目标1相关的研究活动制备的新型材料底物上。具体目标3：评估MSCs在纳米结构基质上的成骨分化。据推测，在粘附之后，MSCs的迁移将受到底物表面的表面梯度的影响，其中选择的蛋白质已被吸附，最重要的是，显示出促进后续细胞粘附和新组织形成相关功能的适当结构域。拟议的研究从根本上不同于过去和目前的方法，因为它将开发一种新的工艺，允许对各种化学计量组合的多种材料配方进行高通量测试。本研究有望实现以下目标：(1)阐明蛋白质在新型底物上的吸附、粘附和细胞功能；(2)建立这些金属氧化物底物作为高通量细胞相容性评估平台的潜力。

DESCRIPTION (provided by applicant): The overall objective of this project is to develop a foundation for a biomaterial screening strategy based on combinatorial materials science. This approach will provide substrates with a range of subtle changes in surface properties and composition. The efficacy of these novel material formulations will be determined in vitro using cell-culture models and by conducting a systematic investigation of the effects of the elemental composition of the biomaterial surface chemistry and topography on mesenchymal stem cell (MSC) differentiation and functions pertinent to new bone formation. The central hypothesis is that the metal oxide surface of the material substrate modulates the type, distribution and conformation of adsorbed proteins, these proteins direct and modulate subsequent cell interaction and function pertinent to new tissue formation. Specific Aim 1: Develop metal oxide substrates based on titanium that contain gradients of three other metals used as implant materials. It is hypothesized that, annealing by plasma-enhanced chemical vapor deposition, will generate concentration gradients using thin films of variable thickness sputtered onto Ti substrates. Specific Aim 2: Determine the type, distribution and conformation of select serum and/or ECM adhesive proteins such as collagen type I, fibronectin, laminin, and vitronectin, adsorbed onto the novel material substrates prepared by the research activities pertinent to Specific Aim 1. Specific Aim 3: Assess the osteogenic differentiation of MSCs onto the nanostructured substrates. It is hypothesized that following adhesion, MSCs migration will be affected by the surface gradients to regions on the substrate surface where select proteins had adsorbed and, most importantly, exhibit appropriate domains which promote subsequent cell adhesion and functions pertinent to new tissue formation. The proposed research is fundamentally different from past and current approaches in that it will develop a new process that will allow high-throughput testing of multiple material formulations of various stoichiometric combinations. This research is expected to achieve the following: (1) elucidate aspects of protein adsorption and adhesion and function of cells on the novel substrates; and (2) establish the potential of these metal oxide substrates as a high-throughput cytocompatibility assessment platform. PUBLIC HEALTH RELEVANCE: With a U.S. Prosthetic Implant market of about $1 billion a year and growing at a rate of 10% a year, any improvement in osseointegration and life of the prosthetic implant will have a drastic economic effect, especially if one takes into consideration that up to 30% of the implants in procedures such as hip replacement do not show appropriate osseointegration. The proposed project aims to improve the number of candidate biomaterials screened for improved osseointegration by investigating the effect of the material surface properties and protein adsorption on osteogenic mesenchymal stem cell behavior, using state of the art surface characterization and gene expression technologies.