Développement des systèmes biomédicaux à la base des cristaux liquides

液晶(LC)材料经历了一段不平凡的旅程，从奇异而迷人的材料演变为每年1000亿美元的平板液晶显示器产业。这种“转变”的主要物理机制是它们对电场的敏感性(不提视觉交流对人类的重要性)。 然而，这些材料可以提供更多的东西。事实上，越来越多的证据表明，在生物系统和过程中，相同的基本物理机制(与那些支配LC材料的机制)具有重要作用。例如，研究表明，在甲壳素或胶原的溶液中可以观察到各向异性的LC相。天然粘液和滑液也可以表现为LC期。生物组织有许多其他弹性各向异性液体或凝胶状态，生物膜(如髓鞘)可能是最引人注目的例子之一。 同时，众所周知，大多数药物都是手性分子，手性在生物界中的作用极其重要。此外，我们最近发现，手性也可能显著影响药物扩散过程，其中许多关键问题仍未得到解答。例如，由于扩散的限制，注射到脑脊液中的药物很难渗透到脑组织中，其机制尚不清楚。因此，更好地了解这些机制可能有助于优化代表巨大社会和经济利益的药物制造和给药方法。 毫无疑问，生物世界中发生的许多基本过程(如分子扩散、定向组织、细胞膜的弹性结构变形、轴突的导电性等)。与液晶材料中存在的物理过程有深刻的相似之处。我相信，利用我们在上个世纪积累的LCS物理知识，将有助于我们更好地了解生物过程，并使新的医学解决方案成为可能。 在这项研究计划的框架内，我们将研究手性分子与对应于特定生物情况的各种LC组织模型相互作用的物理机制，如膜、粘液等。我们将与生物医学界的专家合作，为此类实验模拟确定最现实的条件。然后，我们将使用获得的结果来设计和执行真实生物样本和真实手性药物(而不是任意选择的手性分子)的实验。这将首先在体外(在组织切片上)，然后在体内(使用我们的适应性内窥镜工具)。最后，我们将探索增加手性扩散屏障(用于药物过滤)效果的可能性，或者相反，为了更好地传递药物而减少它的方法。

Liquid crystal (LC) materials have gone through an extraordinary journey evolving from exotic and fascinating materials to an industry of flat panel LC displays amounting to $100 Billion / year. The main physical mechanism of this “transformation” is their sensitivity to the electric field (without mentioning the importance of visual communication for humans). However, those materials have much more to offer. Indeed, an increasing amount of evidence is available pointing to the important role of the same fundamental physical mechanisms (as those governing LC materials) in biological systems and processes. For example, it was shown that the anisotropic LC phase can be observed in solutions of chitin or collagen. Natural mucus and synovial fluid can also show an LC phase. Biological tissue has many other elastic anisotropic liquid or gelly states, probably the biological membrane (such as myelin) being one of the most striking examples. At the same time, it is well known that the majority of drugs are chiral molecules and the role of chirality is extremely important in the biological world. In addition, we have recently discovered that chirality could also significantly affect the drug diffusion processes where many key questions remain unanswered. For example, a drug injected into the cerebrospinal fluid poorly penetrates into brain tissue owing to the limitations of diffusion, the mechanisms of which are not well understood yet. A better understanding of those mechanisms might thus help in optimizing drug fabrication and delivery methods that represent huge social and economic interest. There is no doubt that many fundamental processes taking place in the biological world (such as molecular diffusion, orientational organization, elastic structural deformation of cell membranes, electric conductivity in axons, etc.) have deep analogies with physical processes present in LC materials. I believe that the use of our knowledge of the physics of LCs accumulated during the last century will help us to better understand the biological processes and to enable new medical solutions. In the framework of this research program, we shall study the physical mechanisms of interaction of chiral molecules with various LC tissue models corresponding to specific biological cases, such as membranes, mucus, etc. We shall collaborate with experts from the biomedical community to identify the most realistic conditions for such experimental simulations. We shall then use the results obtained to design and execute experiments with real biological samples and real chiral drugs (instead of arbitrarily chosen chiral molecules). This will be done first in-vitro (on tissue slices) and then in-vivo (using our adaptive endoscopy tools). Finally, we shall explore the possibilities of increasing the effect of the chiral diffusion barrier (for drug filtering) or, in contrast, the ways of reducing it for better drug delivery.