Self-assembling Liposome Nano-transducers

换能器是一种能将电能转化为机械能，反之亦然的装置。它们被广泛用于无损检测，在测试材料中产生声信号，并检测声信号在传播过程中的变化，从而确定材料的特性。传感器在无损检测中的应用领域是多种多样的，从定位金属结构中的裂缝到诊断人类疾病。换能器通常由石英或陶瓷等单晶制成。最近有研究表明，如果将材料缩小到纳米级，则更广泛的材料可用于换能器。事实上，已经有研究表明，电能可以在生物膜中转化为机械能。此外，还确定了大大增加这种效应大小的策略。这些发现非常令人兴奋，因为它们为开发可用于人体而不造成任何毒性风险的微型传感器铺平了道路，因此在医学上具有巨大的应用潜力。本奖学金中提出的工作集中于开发由磷脂制成的纳米级传感器，磷脂是生物细胞膜中发现的主要脂肪类型。提出的纳米换能器的一个巨大应用领域是医学成像，这提出了许多挑战。在实践中，纳米换能器可用于远程探测组织特性，并用于成像系统以帮助疾病诊断。人们也越来越需要能够远程研究体内细胞和组织的新型成像系统，以支持新兴疗法的发展，这些疗法利用人类细胞治疗目前无法治愈的疾病，如帕金森病和脊髓损伤，以及包括糖尿病和心脏病在内的慢性疾病。希望是通过将新的健康细胞引入体内，它们将有助于恢复受伤或患病细胞的功能。为了确保这些疗法有积极的效果，重要的是，一旦进入体内，就必须追踪引入细胞的位置和行为。这是一个具有挑战性的问题，目前的技术正在努力解决。本研究金提出的工作将解决上述挑战。将采取的方法与其他工人不同，特别是因为它将涉及由有机材料制成的换能器的开发。这项工作的主要部分将是设计和制造纳米换能器。组成纳米换能器的磷脂将形成称为脂质体的气泡。由于脂质体的电学和力学性质之间的自然联系，将有可能将它们用作微小的声源。基于脂质体组成、形状和大小的修饰，将开发增加声信号大小的策略。该奖学金的另一部分将是使用纳米换能器开发一种合适的成像系统，该系统可用于产生身体的诊断图像。此外，通过用特定的生物分子修饰脂质体，纳米换能器将能够瞄准特定的细胞类型，使它们能够作为定位体内细胞的信标。工作的最后一部分将集中在展示新的成像系统的能力，使用模仿人体的组织幻影。特别是，检测肿瘤、脑电活动和追踪用于治疗的细胞的能力将被研究。总的来说，这项工作的成功将提供一种新的医学成像模式，可以在护理点的临床途径中很容易地实施。这将对医疗保健产生重大影响，并使临床使用的新疗法成为可能，从而为社会的健康和财富作出贡献。

Transducers are devices that can convert electrical energy into mechanical energy and vice versa. They are widely used in non-destructive testing to generate acoustic signals in test materials and to detect changes in the acoustic signal as it travels enabling material properties to be determined. The application areas for transducers in non-destructive testing are diverse and range from locating cracks in metal structures to diagnosing disease in humans. Transducers are typically made from single crystals such as quartz or ceramics. Recently it has been shown that a much wider range of materials can be used in transducers if they are miniaturised down to a nanometre scale. In fact, it has been shown that electrical energy can be converted to mechanical energy in biological membranes. Further, strategies to greatly increase the size of this effect have also been identified. These findings are very exciting as they pave the way for development of tiny transducers that could be used in the human body without posing any risk of toxicity, thus having tremendous potential for application in medicine. The work proposed in this Fellowship is centred on the development of nano-sized transducers made from phospholipids, which are the main type of fat found in membrane of biological cells. A huge area of application for the nano-transducers proposed is in medical imaging which presents a number of challenges. In practice, the nano-transducers could be used to remotely probe tissue properties and used in an imaging system to aid the diagnosis of disease. There is also a growing need for new imaging systems capable of remotely studying cells and tissues in the body to support the development of emerging therapies that use human cells to treat currently incurable conditions, such as Parkinson's disease and spinal injury, as well as chronic conditions including diabetes and heart disease. The hope is that by introducing new healthy cells into the body they will help to restore the function of injured or diseased cells. To ensure these therapies have a positive effect it is important that the location and behaviour of introduced cells are tracked once in the body. This is a challenging problem which current technologies are struggling to address. The work proposed in this Fellowship will address the above challenges. The approach that will be taken is different from other workers particularly as it will involve the development of transducers made from organic material. A major part of the proposed work will be designing and fabricating the nano-transducers. The phospholipids the nano-transducers will be composed of will be formed into bubbles called liposomes. Due to the natural link between the electrical and mechanical properties of liposomes it will be possible to use them as tiny acoustic sources. Strategies to increase the size of the acoustic signal produced will be developed based on modification of the liposome composition, shape and size. Another part of this Fellowship will be the development of a suitable imaging system using the nano-transducers that can be used to produce diagnostic images of the body. Also by controllably decorating the liposomes with specific biological molecules the nano-transducers will be able to target certain cell types enabling them to act as beacons to locate cells in the body. The final part of the work will be centred on demonstrating the capability of the new imaging system using tissue phantoms that mimic the human body. In particular, the ability to detect tumours, electrical activity in the brain and track cells used in therapy will be investigated. Overall, the success of this work will deliver a new medical imaging modality that could be implemented readily within clinical pathways at the point of care. This would have a significant impact on healthcare and enable new therapies to become available for clinical use and thus contribute to the health and wealth of society.