Department of Chemistry "Giacomo Ciamician", Alma Mater Studiorum - University of Bologna, Via Selmi 2, 40126 Bologna, Italy.
Department of Chemistry, University of Turin, Via Pietro Giuria, 7, 10125 Turin, Italy.
Biosens Bioelectron. 2019 Mar 15;129:260-268. doi: 10.1016/j.bios.2018.09.059. Epub 2018 Sep 17.
During space missions, real-time monitoring of astronauts' health status is of crucial importance and therefore there is a strong demand for simple analytical devices that astronauts can use to perform clinical chemistry analyses directly onboard. As part of the "IN SITU Bioanalysis" project, we designed a biosensor for analysing salivary levels of cortisol in astronauts, a marker of chronic stress. The biosensor is based on the Lateral Flow Immunoassay (LFIA) approach coupled with chemiluminescence (CL) detection and comprises a 3D-printed plastic cartridge containing a sealed fluidic element with the LFIA strip, in which the flow of sample and reagents is activated by pressing buttons on the cartridge and sustained by exploiting capillary forces. For measurement, the photon emission is imaged employing a CL reader based on an ultrasensitive cooled charge-coupled device (CCD) camera. The payload was designed to operate in microgravity and to withstand mechanical stress, such as take-off vibrations, and onboard depressurization events, while the microfluidics was developed considering alterations of physical phenomena occurring in microgravity, such as bubble formation, surface wettability and liquid evaporation. The biosensor, which was successfully used by the Italian astronaut Paolo Nespoli during the VITA mission (July-December 2017), demonstrated the feasibility of performing sensitive LFIA analysis of salivary cortisol down to 0.4 ng/mL directly onboard the International Space Station. It could be easily adapted for the analysis of other clinical biomarkers, thus enabling the early diagnosis of diseases and the timely activation of appropriate countermeasures.
在太空任务中，实时监测宇航员的健康状况至关重要，因此强烈需要简单的分析设备，让宇航员能够直接在船上进行临床化学分析。作为“原位生物分析”项目的一部分，我们设计了一种用于分析宇航员唾液中皮质醇水平（慢性应激的标志物）的生物传感器。该生物传感器基于侧向流动免疫分析（LFIA）方法，并结合化学发光（CL）检测，包括一个 3D 打印的塑料盒，其中包含一个密封的流体制件和 LFIA 条带，通过按下盒上的按钮激活样品和试剂的流动，并利用毛细作用力维持流动。为了进行测量，采用基于超灵敏冷却电荷耦合器件（CCD）相机的 CL 读取器对光子发射进行成像。该有效载荷设计用于微重力环境，并能承受机械应力，如起飞振动和船上减压事件，而微流控技术则是考虑到微重力环境中发生的物理现象的变化而开发的，如气泡形成、表面润湿性和液体蒸发。该生物传感器已成功由意大利宇航员 Paolo Nespoli 在 VITA 任务（2017 年 7 月至 12 月）中使用，证明了在国际空间站上直接进行敏感的 LFIA 分析唾液皮质醇至 0.4ng/mL 的可行性。它可以很容易地适应其他临床生物标志物的分析，从而能够实现疾病的早期诊断和及时采取适当的对策。
