Photonic Sensing and Dual-mode Bio-Imaging with Rare Earth Upconversion Nanoparticles

包括急性心肌梗死（AMI）和脑卒中在内的心血管疾病（CVD）是世界范围内过早死亡的主要原因。CVD的性质要求比目前无法或耗时的方法更早地有效和同时检测生物标志物。动脉粥样硬化是一种炎症性疾病，炎症标志物高敏C反应蛋白（CRP）已被证明可以识别其他处于风险中的个体。脂蛋白相关磷脂酶A2（Lp-PLA 2）也是血管炎症的标志物。因此，与例如Lp-PLA 2和hs-CRP两者一起筛查可以提供比单独使用任一测试更好的CVD和中风风险评估。在这个项目中，我们选择了四个生物标志物NT-proBNP，LpPLA 2，GFAP和IL 6，用于实现多生物标志物检测和测量系统。目前用于检测和评估动脉粥样硬化斑块的传统诊断工具具有其局限性，即使是从现代技术如CT和MRI接收的对比度较低的图像。虽然最近的进展，成像技术与蛋白质组学和代谢谱提高了可行性的患者筛查的诊断，他们不适合的“床旁”，早期诊断可能有利于初级预防和治疗这些疾病。“金标准”心脏血管造影术是一种有创方法，具有与导管插入术相关的风险，并且没有可靠的无创方法来识别和量化动脉粥样硬化斑块形成的严重程度。超声扫描目前用于非侵入性地检测斑块负荷，特别是在颈动脉中，但是目前还没有对此的可用解释，其允许区分不稳定斑块与稳定斑块。我们将开发镧系元素掺杂的上转换纳米颗粒（UCNPs）和基于生物分子缀合物的分析，用于快速和同时检测和成像关键生物标志物-治疗心血管疾病和动脉粥样硬化UCNP具有特定的激发和发射波长，并且单个荧光镧系元素离子对它们周围的环境变化非常敏感。该项目旨在为稀土（RE）上转换纳米颗粒（UCNP）创建一个可扩展的制造过程，适用于基于光致发光的快速生物传感和生物成像，同时也排除了由于自体荧光（来自组织的荧光）引起的信号噪声。为了在红外激光激发下获得高输出可见光发射，同时保持生物安全性，需要提高UCNPs的结晶度和稀土掺杂浓度。我们建议扩大适合商业开发的UCNP的可制造性。这些在近红外激发下具有强可见光发射的纳米颗粒将用-Affimers进行表面官能化，以适用于组织和器官的生物安全和靶向激光以及磁（MRI）成像。Affimers是合成的结合蛋白，由利兹大学开发并由Avacta Lifesciences销售。作为进一步的发展，这些适当功能化的颗粒将用于创建芯片实验室设备，用于同时和快速感测CVD生物标志物。通过将成像和传感模式结合在一起，该项目提出开发用于识别、监测和最终检测动脉粥样硬化组织的方法。该项目开发的方法也可能适用于各种形式的癌症生物标志物检测和组织成像。

Cardiovascular diseases (CVD) which include acute myocardial infarction (AMI) and stroke are the main cause of premature deaths in the world. The nature of CVD demands efficient and simultaneous detection of biomarkers earlier than current approaches that are incapable or time consuming. Atherosclerosis is an inflammatory disease, and inflammatory marker high-sensitivity C-reactive protein (CRP), has been shown to identify additional individuals who are at risk. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is also a marker of vascular inflammation. Thus screening with for example both Lp-PLA2 and hs-CRP may provide a better risk assessment for CVD and stroke than using either test alone. In this project we have chosen four biomarkers NT-proBNP, LpPLA2, GFAP and IL6 for implementing a multiple biomarker detection and measurement system. Traditional diagnostic tools currently used for detection and assessing atherosclerotic plaques have their limitations regarding the less contrast images received even from modern techniques such as CT and MRI. Although recent advances in imaging techniques together with proteomics and metabolic profiling have enhanced the feasibility of patient screening for the diagnosis, they are not suitable for the "point-of-care" where the early diagnosis may benefit primary prevention and treatment of these diseases. The "gold standard" cardiac angiography is an invasive method with risks associated with the catheterization procedure and there is no reliable non-invasive method to identify and quantify the severity of atherosclerotic plaque formation. Ultrasound scan is currently used for detecting plaque burden non-invasively, particularly in the carotids, but there is no currently available interpretation of this that allows differentiation of unstable vs stable plaques.In this interdisciplinary project, we will develop lanthanide doped up-conversion nanoparticles (UCNPs) and biomolecular conjugate based assays for the rapid and simultaneous detection and imaging of key biomarkers - for CVD and atherosclerosis. UCNPs have specific excitation and emission wavelengths, and the individual fluorescent lanthanide ions are very sensitive to environmental alterations around them. The project aims to create a scalable manufacturing process for rare earth (RE) upconversion nanoparticles (UCNP) suitable for photoluminescence based rapid bio-sensing and bio-imaging that also preclude signal noise due to autofluorescence (fluorescence from tissues). The crystallinity and RE doping concentration of the UCNPs need improvement for high output visible light emission under infrared laser excitation while being biologically safe. We propose to scale up the manufacturability of the UCNPs suitable for commercial exploitation. These nanoparticles with intense visible light emission under near infrared excitation will be surface functionalised with -Affimers to be suitable for biologically safe and targeted laser based as well as magnetic (MRI) imaging of tissues and organs. Affimers are synthetic binding proteins, developed at the University of Leeds and marketed by Avacta Lifesciences. As a further development, these particles suitably functionalised will be used to create lab-on-a-chip device for simultaneous and rapid sensing of CVD biomarkers. By bringing together imaging and sensing modalities, this project proposes to develop methodologies for identifying, monitoring and finally detecting atherosclerotic tissues. The methodology developed in the project might also be applicable to various forms of cancer biomarker detection and tissue imaging.