Mechanobiology-based medicine

如今，诊断在很大程度上是通过识别与病理状态发生相关的分子标记来实现的。然而，许多疾病逃脱了这一范式，因为变异细胞的生化指纹与健康细胞没有显著差异，阻碍了早期诊断，并降低了治疗的影响。一个典型的例子是白血病，这是一种每年导致世界上30多万人死亡的癌症。这种疾病的演变是随着我们年龄的增长而发生的，但现在有证据表明，我们体内的细胞在用目前的诊断技术识别之前多年就向恶性表型进化。这项提议将利用机械生物学这一在过去10年中取得进展的研究领域，作为一种新的方法来询问细胞状态的非常早期的变化，通过将先进的生物材料、新的显微技术和机器人技术相结合，使其更接近医疗用途。机械生物学告诉我们，细胞可以感觉到机械环境并对其做出反应。例如，癌细胞比正常细胞柔软。然而，它们生态位的重组会导致组织硬度的增加。在这里，我们将使用机械刺激来询问细胞是否有可能成为癌细胞。细胞对这些外部机械刺激的反应将揭示它们从健康演变为疾病的可能性。我们将专注于白血病，一种起源于骨髓的癌症，因为正常的造血干细胞对我们的血液起着至关重要的作用，开始恶性转化，产生白血病干细胞。当这种情况发生时，我们建议MSCs增殖并产生新的细胞外基质，导致更严格的环境。人们认为，环境的这些变化会引发白血病细胞的进一步扩张，反之亦然。该项目将使用具有明确机械和生化特性的软水凝胶来开发骨髓的体外模型，这些水凝胶可以承载间充质干细胞和造血(或白血病)干细胞。我们将研究使用受控频率和幅度的纳米级振动对模型进行外部机械刺激如何刺激两种细胞群，以识别并最大化由白血病细胞的存在引发的变化。为了监测骨髓模型中的这些机械变化，我们将开发用于生物学背景的布里渊显微镜。这项技术基于声波在系统中的传播，以表征机械特性，并将允许以非侵入性方式详细映射骨髓模型的硬度随时间的函数--重要的是以非侵入性方式。此外，机械刺激的水平将取决于布里渊显微镜提供的读数，该读数将馈入控制系统以改变施加在骨髓模型上的机械振动刺激的水平。我们将首先调查我们的技术在我们的骨髓模型中检测单个白血病细胞存在的敏感性，然后，我们将通过我们的临床合作者，对具有潜在白血病转化早期迹象或随着年龄增长保持健康的患者细胞进行概念验证实验。

Nowadays diagnosis is largely enabled by the identification of molecular markers associated with the onset of a pathological state. Nevertheless, many diseases escape this paradigm, as the biochemical fingerprint of the aberrant cells do not differ significantly from healthy ones, hindering early diagnosis and reducing the impact of treatments. One prototypical example is Leukaemia, a type of cancer that kills more than 300,000 people in the world every year. The evolution of the disease happens as we get older, but there is now evidence that cells in our body progress towards a malignant phenotype many years before they can be identified with current diagnostic techniques. This proposal will exploit mechanobiology, a field of research that has progressed in the last 10 years, as a novel method to interrogate very early changes in cellular state, bringing it closer to medical use by combining advanced biomaterials, novel microscopy techniques and robotics. Mechanobiology has taught us that cells can feel and react to their mechanical environment. For example, cancer cells are softer than normal cells. However, reorganisation of their niche causes increased tissue stiffness. Here, we will use mechanical stimulation to interrogate cells potential to become cancer cells. Cell response to these external mechanical stimuli will reveal their potential to evolve from health to disease.We will focus on leukaemia, a cancer that originates in the bone marrow, as normal haematopoietic stem cells, which play the essential role to make our blood, start a malignant transformation giving rise to leukaemic stem cells. When this happens, we propose MSCs proliferate and produce new extracellular matrix, leading to a stiffer environment. It is believed that these changes in the environment trigger further expansion of leukaemic cells and vice versa. This project will develop an in vitro model of the bone marrow using soft hydrogels with defined mechanical and biochemical properties that host mesenchymal stem cells and hematopoietic (or leukaemic) stem cells. We will investigate how external mechanical stimulation of the model using nanoscale vibration of controlled frequency and amplitude can stimulate both cell populations to identify and maximise changes triggered by the presence of leukaemic cells. To monitor these mechanical changes in the bone marrow model we will develop Brillouin microscopy for use in a biological context. This technique is based on the propagation of acoustic waves in the system to characterise mechanical properties and will allow detailed mapping of stiffness of the bone marrow model as a function of time - importantly in a non-invasive way. Moreover, the level of mechanical stimulation will be dependent on the readout provided by Brillouin microscopy that will feed into a control system to alter the level of the mechanical vibrational stimulation imposed on the bone marrow model.We will first investigate the sensitivity of our technology to detect the presence of a single leukaemic cell in our bone marrow model and then, we will establish a proof of concept experiment with patient cells, through our clinical collaborators, that either have early signs of potential leukemic transformation or remain healthy as they age.