RAPID: On-mask Chemical Modulation of Respiratory Droplets

摘要：传染性呼吸道疾病的传播，如流感、SARS、中东呼吸综合征和COVID-19，通常是从携带病毒的呼吸道飞沫开始的，这些飞沫是由感染者在咳嗽或打喷嚏时释放的。大多数液滴最终沉积在各种表面，如门把手、桌面、按钮、扶手和触摸屏上，使它们变成潜在的传染性物体。要发生感染，这些病毒粒子必须在被另一个人（通常是通过手的直接接触）携带后保持活性，然后转移到口、鼻和眼睛。携带病毒的飞沫和病毒核也有可能通过在传染源附近吸入而直接进入呼吸道。因此，为了减缓甚至阻止病毒的传播，需要大大减少刚刚释放的呼吸道飞沫中病毒粒子的数量和活性。该RAPID奖由材料研究部固态和材料化学项目支持，旨在探索通过医用口罩的呼吸道液滴中病毒粒子失活的化学调节策略。这可以减少活跃病毒粒子在其传播途径的源头，即咳嗽的数量。该项目还有助于发起一项努力，召集物理科学和工程领域的研究人员研究这些问题，发展新的假设，创造以用户为中心的解决方案，并教育公众，以应对与传染性呼吸道疾病的传播和传播有关的许多挑战。技术摘要：患者通常需要口罩来阻挡和吸收较大的呼吸道液滴，并改变较小的逃逸液滴的路径，以减少其向前传播的距离。因此，有必要开发出在患者使用的一次性口罩中增加抗病毒功能的策略。这个由材料研究部固态和材料化学项目支持的RAPID项目，开发了这样一种面罩上的化学调节策略，重点是改变逸出的呼吸道飞沫的化学成分，以使病毒粒子失活。启动模型体系是一种基于导电聚合物的化学改性剂。这种聚合物中掺杂了化学物质，已知这些化学物质会产生恶劣的微环境，使病毒粒子失活。在呼气过程中，这些掺杂剂可以很容易地溶解在温暖的呼吸道液滴中，但在吸入过程中，它们不会在进入的更冷、更干燥的空气流中蒸发。这种面罩上化学调节策略为普通医用口罩增加了化学消毒功能，以降低病毒粒子的生存能力。由于这种滴入式化学调节是在病毒传播链事件的最开始应用的，因此它对所有潜在的传播途径都有效。此外，通过该奖项，生物/医学研究与物理科学/工程之间建立了更强的联系，并有助于激发新的假设、问题和想法，推动创新，以解决与传染性呼吸道疾病的传播和传播相关的挑战。RAPID项目的一项重大努力就是为了实现这一目标，以便物理科学和工程界能够得到更好的信息和教育，并做好准备，与生物和医学研究人员合作，创造解决方案，并与他们一起参加面向公众的教育推广活动。该奖项反映了美国国家科学基金会的法定使命，并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。

NON-TECHNICAL ABSTRACT: Spread of infectious respiratory diseases, such as influenza, SARS, MERS, and COVID-19, usually starts from virion-laden respiratory droplets, which are released by an infected person during coughing or sneezing. Most of the droplets end up depositing on various surfaces such as doorknobs, tabletops, buttons, handrails, and touchscreens, turning them into potentially infectious objects. For infection to occur, these virions must remain active when they are picked up by another person, often through direct contact by hands, and then transferred to mouth, nose and eyes. Direct transport of virus-laden droplets and nuclei to the respiratory tract is also possible through inhaling within close proximity to the source. Therefore, to slow down or even prevent virus spread, it would be desirable to greatly reduce the number and activity of the virions in those just-released respiratory droplets. This RAPID award, which is supported by the Solid State and Materials Chemistry Program in the Division of Materials Research, explores chemical modulation strategies for deactivating virions in the respiratory fluid droplets passing through a medical mask. This can reduce the number of active virions at the very source of their spread pathways, the cough. The project also helps to seed an effort to rally researchers in physical sciences and engineering to study the problems, develop new hypotheses, create user-centered solutions and educate the general public, to address the many challenges associated with the transmission and spread of infectious respiratory diseases.TECHNICAL ABSTRACT: Facial masks are often required for patients to block and absorb large respiratory fluid droplets, and to reroute those smaller escaping droplets to reduce their forward travelling distance. It would be desirable to develop drop-in strategies to add anti-viral functions to the disposable masks used by patients. This RAPID project, which is supported by the Solid State and Materials Chemistry Program in the Division of Materials Research, develops such an on-mask, chemical modulation strategy that focuses on altering the chemical composition of the escaped respiratory droplets to deactivate virions. The starting model system is a chemical modifier based on a conducting polymer. The polymer is doped with chemical agents that are known to generate harsh micro-environment to deactivate virions. The dopants can readily dissolve in warm respiratory fluid droplets during exhalation, but they do not vaporize in the incoming stream of colder and drier air during inhalation. Such an on-mask chemical modulation strategy adds chemical sanitization function to common medical masks for reducing the viability of virions. Since this drop-in chemical modulation is applied at the very beginning of the chain events of virus transmission, it is effective for all potential transmission pathways. Additionally, through this award stronger connections between biological/medical research and physical sciences/engineering are established and serve to inspire new hypotheses, questions and ideas that drive innovations to address the challenges associated with the transmission and spread of infectious respiratory diseases. A significant effort of this RAPID project is used to achieve this goal, so that the physical sciences and engineering communities can be better informed, educated and prepared to work with biological and medical researchers to create solutions, and join them in the educational outreach activities for the general public.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.