Towards Sustainable Green Composite Materials for Medical Implants

我的研究项目的最终目标是改进骨科植入物，随着更年轻、更活跃的人接受关节置换手术，骨科植入物目前的缺点越来越明显。我的目标是用天然纤维纳米复合材料取代现有的金属植入物，这些植入物在相对较短的时间内容易失败，这些纳米复合材料经过更好的设计，可以更好地模拟真实人类骨骼的结构和机械性能。这些创新的新材料将使用更长时间，降低第二次手术的成本和风险，并将由自然、可再生资源制成。这将带来社会、经济和环境方面的好处：提高患者的生活质量；减少医疗保健系统的压力和成本；促进加拿大生物医疗部门的发展，特别强调一种具有增强特性的绿色产品。 在加拿大和其他地方，髋关节和膝关节置换术的总数正在显著增加。一些人预测，2005年至2030年间，髋关节置换量将增长137%，膝关节置换量将增长670%。仅在美国，每年的手术总数就超过500万例。目前的植入物一般只有10到15年的寿命，主要是因为它们缺乏成功替代人骨所需的生物和机械特性。这意味着越来越多的中年接受替代手术的人可能会经历植入失败。大约30%的50多岁的患者和55%的50岁以下的患者将需要第二次手术，称为翻修，这是复杂和昂贵的，结果不如第一次手术令人满意。 我的研究旨在通过开发结构和机械上更接近人类骨骼的高性能纳米复合材料来应对这一巨大挑战。我将通过使用类似骨骼的增强材料(即纤维素纤维和羟基磷灰石)以及生物聚合物来创建复杂的分层结构来实现这一点。由于它们将以天然纤维素纤维为基础，并经设计使其表现得更像骨骼，因此这些纳米复合生物材料将允许更好的骨-植入物负载转移，并更好地与宿主组织结合。与现有的非有机材料相比，这些增强的性能将转化为更持久、更有效的植入物。 我提出的研究计划包含了许多创新方面。它将创造出新的、高性能、轻质、成本效益高的纳米复合生物材料，为体内测试做好准备。用于制造它们的天然纤维将在加拿大种植。由于这些新材料在环境上是可持续的，它们将减少对不可再生资源的依赖。拟议的研究计划将通过让安大略省的主要组织，如玛氏创新公司和圣迈克尔医院参与临床(体内)测试和商业化，帮助支持将这项研究转化为现实世界的整形外科应用。这将有助于安大略省与主要的全球医疗设备公司成功竞争。此外，由于可持续性方面的原因，这将使加拿大在绿色医疗器械技术及其商业化方面具有特殊优势。因此，这项研究计划的结果将在两个关键领域对加拿大具有持久的战略价值：先进材料和制造以及医疗保健。 拟议的研究计划还将支持在一个重要且不断增长的研究领域形成HQP。它将在急需的领域培训8名HQP(5名研究生和3名本科生)，让他们接触到涉及天然纤维基纳米复合材料的应用研究和开发。这种创造性培训将支持加拿大继续向以知识为基础的经济转型。

The ultimate goal of my research program is to improve orthopaedic implants, whose current drawbacks are increasingly clear as younger, more active people undergo joint replacement surgery. I aim to replace existing metallic implants, which are prone to failure after a relatively short time, with natural-fibre nanocomposites better engineered to mimic the structural and mechanical properties of real human bone. These innovative new materials will last longer, reducing the costs and risks of a second surgery, and will be made from natural, renewable resources. The benefits will be societal, economic and environmental: increased patient quality of life; reduced pressures and costs on the health care system; and advancement of Canada’s bio-medical sector, with a unique emphasis on a green product with enhanced properties. Total hip and knee replacements are increasing significantly in Canada and elsewhere. Some estimates have forecast a rise of up to 137% in hip and 670% in knee replacements between 2005 and 2030. That would total more than 5 million surgeries a year in the U.S. alone. Current implants generally last only 10 to 15 years, largely because they lack the biological and mechanical characteristics needed to successfully replace human bone. This means the growing number of people who have replacement surgery in middle age are likely to experience implant failure. Roughly 30% of patients in their fifties and 55% of patients under 50 will require a second procedure called revision that is complex and costly, with outcomes less satisfactory than in primary surgery. My research aims to address this huge challenge by developing high-performance nanocomposite materials that are structurally and mechanically closer to human bones. I will achieve this by creating complex hierarchical structures using bone like reinforcing materials (i.e., cellulose fibres and hydroxyapatite) along with biopolymers. Because they will be based on natural cellulosic fibres, and engineered to behave more like bone, these nanocomposite biomaterials will allow for a better bone-implant load transfer and better integration with host tissues. These enhanced properties compared to existing, non-organic materials, will translate into longer-lasting and more effective implants. My proposed research program encompasses numerous innovative aspects. It will create new, high-performance, lightweight, cost-effective nanocomposite biomaterials ready for in-vivo testing. The natural fibres from which they will be made will be grown in Canada. Because these new materials will be environmentally sustainable, they will reduce dependency on non-renewable resources. The proposed research program will help support the translation of this research into real-world orthopaedic applications by involving key Ontario organizations such as MaRS Innovation and St. Michael’s Hospital in clinical (in-vivo) testing and commercialization. This will help Ontario to compete successfully with major global medical device companies. Moreover, because of the sustainability aspect, it will give Canada a special advantage in green medical device technology and its commercialization. The outcomes of this research program will therefore be of lasting strategic value to Canada in two vital sectors: advanced materials and manufacturing, and health care. The proposed research program will also support the formation of HQP in an important and growing area of research. It will train 8 HQPs (5 graduate students and 3 undergraduate students) in much-needed areas by exposing them to applied research and development involving natural fibre-based nanocomposite materials. This creative training will support the continuing transformation of Canada to a knowledge-based economy.