Fundamental Study of Odorant Responses of Desiccatable Cells

用于气味识别的人工或电子鼻（e-nose）是几十年来的目标。 然而，在今天的领域中，气味识别的主要和最好的手段仍然是狗，大鼠和人类。 狗可以发现新冠病毒，老鼠可以找到地雷，人类可以识别葡萄酒的年份。 然而，所有这些都需要广泛的个人培训，而且没有留下电子记录。 便携式人工鼻子将在许多领域得到应用，从食品安全到安全。 生物混合传感器是一种很有前途的方法，因为它们将生物细胞检测气味的能力与记录细胞反应的技术相结合。 然而，这种传感器的应用一直受到保持细胞持续存活的需要的阻碍。 该项目的目的是了解一种可以完全干燥的新细胞系，类似于酵母干燥的方式，是否可以形成可用于人工鼻子的基础。 来自昆虫的可干燥细胞已经被创造出来，当它们检测到气味时会发出荧光信号。 细胞可以在需要之前以干燥状态储存在广泛的环境条件下，并且可以通过添加液体来复活。 本项目旨在了解这些细胞对各种气味和暴露条件的反应。人工气味识别将有广泛的应用，有益于社会。 虽然生物气味感测系统由于特异性识别和组合编码而具有无与伦比的选择性和灵敏度，但生物混合传感器的实际实现的挑战一直是维持和储存功能状态的生物元素。 这项基础研究是对可干燥昆虫细胞系的反应，该细胞系已被工程化以表达嗅觉受体（OR）和气味结合后的荧光信号。 这些新的细胞可以在很宽的温度范围内保持冬眠状态，直到使用，绕过了这一障碍。 研究的目的是了解这种细胞是否以及如何用于未来的人工鼻子。 本研究包括四个任务。 1)获得对一组气味物质的浓度-反应曲线，并将其与相应嗅觉感觉神经元的已知反应进行比较。 2)确定响应变异性的来源和幅度，并探讨校准问题。 3)确定响应的时间进程可能包含哪些信息。 4)在其他气味剂存在的情况下，检查细胞对其同源配体（它们最强烈结合的气味剂）的反应。 将传感器的生物成分基本上作为类似于聚合物的材料处理的能力将是突破性的，并且有一天可能允许生物混合传感器离开实验室。该奖项反映了NSF的法定使命，并且通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

An artificial or electronic nose (e-nose) for odor recognition has been a goal for many decades. However, the primary and best means of odor identification in the field today are still dogs, rats, and humans. Dogs can detect COVID, rats can find landmines, and humans can recognize wine vintages. However, all require extensive individual training and none leave an electronic record. A portable artificial nose would have applications in many fields, from food safety to security. Biohybrid sensors are a promising approach, since they combine the ability of biological cells to detect odors with technology to record the cell responses. However, the application of such sensors has been hindered by the need to keep the cells alive continuously. The purpose of this project is to understand whether a new cell line that can be completely dried, similar to the way yeast is dried, could form the basis for a fieldable artificial nose. Dryable cells derived from an insect have been created that give a fluorescence signal when they detect an odor. The cells can be stored under a wide range of environmental conditions in the dry state before they are needed, and can be revived by the addition of liquid. This project seeks to understand the responses of these cells to various odors and exposure conditions.Artificial odor recognition would have a vast range of applications beneficial to society. While biological odor sensing systems have unrivalled selectivity and sensitivity due to specific recognition and combinatorial coding, the challenge to practical realization of biohybrid sensors has been maintenance and storage of the biological elements in a functional state. This fundamental research is on the responses of a desiccatable insect cell line that has been engineered to express an olfactory receptor (OR) and a fluorescence signal upon odorant binding. These novel cells can be kept in a hibernating state, under a wide range of temperatures, until use, circumventing that obstacle. The research objective is to understand whether and how such cells could be employed in a future artificial nose. The research includes 4 tasks. 1) Obtain the concentration-response curves to a panel of odorants and compare them to the known responses of the corresponding olfactory sensory neurons. 2) Ascertain the sources and magnitudes of response variability and explore the issue of calibration. 3) Determine what information the time courses of the responses may contain. 4) Examine the response of the cells to their cognate ligand (the odorant to which they bind most strongly) in the presence of other odorants. The ability to treat the biological components of the sensor essentially as a material similar to a polymer would be ground-breaking and may one day allow biohybrid sensors to leave the laboratory.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.