Biointerfaces: a surface science perspective

骨骼和其他坚固而坚韧的天然材料的特殊性能来自于它们由坚硬的矿物和柔软的有机物组成的结构。有机成分充当矿物形成和生长的支架。这个过程也被称为生物矿化，由许多蛋白质协调;由于其复杂性，我们仍然不完全了解其分子机制。我们的计划旨在填补一些关键的空白。例如，我们想了解蛋白质的化学性质（电荷、亲水性）如何影响矿物质的形成;或者矿物质存款在其上的有机支架如何决定它们如何随时间转变。了解这一点将使我们能够制定促进或抑制矿物质形成的策略，以促进骨骼愈合或阻止发生在不必要的位置（如心血管系统）的钙化。 为了实现这些目标，我们从研究小鼠或人类骨骼、牙齿和病理沉积物中的矿物质开始。我们用许多不同的技术来观察它们的物理化学结构，重点是矿物和有机支架之间的界面。这使我们能够研究矿物形成的早期阶段，因此我们可以根据我们的最终应用抑制或促进这一过程。为了了解所有涉及的变量并测试我们的策略，我们准备了合成模型，试图重现矿物形成的生物环境。例如，我们有一个基于弹性蛋白的模型，弹性蛋白是矿物质经常沉积在动脉中的支架。这个模型可以概括我们在小鼠中观察到的矿物质转化，但我们需要改进它以重现其他重要方面，例如沉积物的形状。 我们将从研究天然矿物质和在实验室中模拟其形成中获得的理解应用于三个主要目标：提出阻止动脉中矿物质形成的策略;涂覆骨植入物的表面，使其与骨牢固结合，并且在长期使用时不会失效;并设计和合成先进的复合材料，由于它们的界面模仿生物矿物质的表面，自然形成并附着。该计划将改善数百万需要骨骼手术或受心血管钙化影响的人的生活质量，并加强加拿大作为先进材料制造业领导者之一的地位。

The exceptional properties of bone and other strong and tough natural materials derive from their structure built from both hard minerals and soft organics. The organic component acts as a scaffold onto which minerals form and grow. This process, also known as biomineralization, is orchestrated by many proteins; due to its complexity, we still do not fully understand its molecular mechanism. Our program aims at filling some crucial gaps. For example, we want to understand how the chemical nature (charge, hydrophilicity) of the proteins influence mineral formation; or how the organic scaffold onto which the minerals deposit determines how they transform over time. Understanding this will allow us to develop strategies to either promote or inhibit mineral formation, to favor bone healing or stop calcifications that occur in unwanted locations, like the cardiovascular system. To achieve these goals, we start from studying minerals derived from bones, teeth, and pathological deposits in mice or humans. We look at their physico-chemical structure with many different techniques, focusing on the interface between the mineral and the organic scaffold. This allows us to study the very early stages of mineral formation, so that we can either inhibit or promote this process depending on our final application. To understand all the variables involved and test our strategies, we prepare synthetic models that try to reproduce the biological environment in which minerals form. For example, we have a model based on elastin, the scaffold onto which minerals are often deposited in the arteries. This model can recapitulate the mineral transformations we observed in mice, but we need to improve it to reproduce other important aspects such as the shape of the deposits. We apply the understanding we gain from studying the natural minerals and mimicking their formation in the lab to three main goals: propose strategies to stop mineral formation in arteries; coat the surface of bone implants so that they strongly bind to bone and do not fail upon extended use; and design and synthesize advanced composite materials that will be extraordinarily tough thanks to their interfaces mimicking the surface onto which biominerals naturally form and adhere to. This program will improve life quality for the millions of people needing bone surgeries or affected by cardiovascular calcification, and strengthen Canada's position as one of the leaders in advanced materials manufacturing.