Combinatorial Metal Oxide Substrates to Enhance Osteogenic Stem Cell Functions

描述（由申请人提供）：本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。这种方法将为基材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使用细胞培养模型并通过对生物材料表面化学和形貌的元素组成对间充质干细胞（MSC）分化和与新骨形成相关的功能的影响进行系统研究来确定。中心假设是材料基底的金属氧化物表面调节吸附的蛋白质的类型、分布和构象，这些蛋白质指导和调节与新组织形成相关的后续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基质，其中包含用作植入材料的其他三种金属的梯度。据推测，退火等离子体增强化学气相沉积，将产生浓度梯度，使用可变厚度的薄膜溅射到钛基板上。具体目标二：确定选择的血清和/或ECM粘附蛋白的类型、分布和构象，如I型胶原蛋白、纤连蛋白、层粘连蛋白和玻连蛋白，吸附在通过特定目标1相关研究活动制备的新型材料基质上。具体目标3：评估MSC在纳米结构基底上的成骨分化。据推测，粘附后，MSC迁移将受到表面梯度的影响，基质表面上的区域，选择蛋白质吸附，最重要的是，表现出适当的结构域，促进后续的细胞粘附和功能相关的新组织形成。拟议的研究与过去和当前的方法有着根本的不同，因为它将开发一种新的工艺，可以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）阐明蛋白质吸附和粘附以及细胞在新型基底上的功能;（2）建立这些金属氧化物基底作为高通量细胞相容性评估平台的潜力。 公共卫生相关性：美国假体植入物市场每年约为10亿美元，并以每年10%的速度增长，假体植入物的骨整合和寿命的任何改善都将产生巨大的经济效应，特别是如果考虑到在诸如髋关节置换术的手术中高达30%的植入物没有显示出适当的骨整合。拟议项目旨在通过研究材料表面特性和蛋白质吸附对成骨间充质干细胞行为的影响，使用最先进的表面表征和基因表达技术，增加筛选用于改善骨整合的候选生物材料的数量。

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.