Micochova Petra, Chadha Ambika, Hesseloj Timi, Fraternali Franca, Ramsden Jeremy J, Gupta Ravindra K
Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), University of Cambridge, Cambridge, UK.
University of Cambridge Addenbrooke's Hospital Cambridge, Cambridge, UK.
Wellcome Open Res. 2021 Sep 9;6:56. doi: 10.12688/wellcomeopenres.16577.2. eCollection 2021.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission occurs via airborne droplets and surface contamination. Titanium dioxide (TiO ) coating of surfaces is a promising infection control measure, though to date has not been tested against SARS-CoV-2. : Virus stability was evaluated on TiO - and TiO -Ag (Ti:Ag atomic ratio 1:0.04)-coated 45 x 45 mm ceramic tiles. After coating the tiles were stored for 2-4 months before use. We tested the stability of both SARS-CoV-2 Spike pseudotyped virions based on a lentiviral system, as well as fully infectious SARS-CoV-2 virus. For the former, tile surfaces were inoculated with SARS-CoV-2 spike pseudotyped HIV-1 luciferase virus. At intervals virus was recovered from surfaces and target cells infected. For live virus, after illuminating tiles for 0-300 min virus was recovered from surfaces followed by infection of Vero E6 cells. % of infected cells was determined by flow cytometry detecting SARS-CoV-2 nucleocapsid protein 24 h post-infection. After 1 h illumination the pseudotyped viral titre was decreased by four orders of magnitude. There was no significant difference between the TiO and TiO -Ag coatings. Light alone had no significant effect on viral viability. For live SARS-CoV-2, virus was already significantly inactivated on the TiO surfaces after 20 min illumination. After 5 h no detectable active virus remained. Significantly, SARS-CoV-2 on the untreated surface was still fully infectious at 5 h post-addition of virus. Overall, tiles coated with TiO 120 days previously were able to inactivate SARS-CoV-2 under ambient indoor lighting with 87% reduction in titres at 1h and complete loss by 5h exposure. : In the context of emerging viral variants with increased transmissibility, TiO coatings could be an important tool in containing SARS-CoV-2, particularly in health care facilities where nosocomial infection rates are high.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）通过空气飞沫和表面污染传播。表面的二氧化钛（TiO₂）涂层是一种很有前景的感染控制措施，不过迄今为止尚未针对SARS-CoV-2进行测试。：在45×45毫米的TiO₂和TiO₂-Ag（Ti:Ag原子比1:0.04）涂层陶瓷砖上评估病毒稳定性。瓷砖涂层后在使用前储存2至4个月。我们测试了基于慢病毒系统构建的SARS-CoV-2刺突假型病毒颗粒以及具有完全感染性的SARS-CoV-2病毒的稳定性。对于前者，在瓷砖表面接种SARS-CoV-2刺突假型HIV-1荧光素酶病毒。每隔一段时间从表面和感染的靶细胞中回收病毒。对于活病毒，在对瓷砖照射0至300分钟后，从表面回收病毒，随后感染Vero E6细胞。通过流式细胞术在感染后24小时检测SARS-CoV-2核衣壳蛋白来确定感染细胞的百分比。照射1小时后，假型病毒滴度降低了四个数量级。TiO₂涂层和TiO₂-Ag涂层之间没有显著差异。仅光照对病毒活力没有显著影响。对于活的SARS-CoV-2，照射20分钟后，病毒在TiO₂表面已显著失活。5小时后没有可检测到的活性病毒残留。值得注意的是，在添加病毒5小时后，未处理表面上的SARS-CoV-2仍具有完全感染性。总体而言，120天前涂有TiO₂的瓷砖能够在室内环境光线下使SARS-CoV-2失活，1小时时滴度降低87%，暴露5小时后完全失活。：在具有更高传播性的新出现病毒变体的背景下，TiO₂涂层可能是控制SARS-CoV-2的重要工具，特别是在医院感染率高的医疗保健设施中。
