Zhao Yun, Dong Jianfei
School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China.
Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China.
Biomed Opt Express. 2022 Jul 28;13(8):4429-4444. doi: 10.1364/BOE.468445. eCollection 2022 Aug 1.
RNA viruses are ubiquitous in nature, many of which can cause severe infectious syndromes to humanity, e.g., the SARS-CoV-2 virus. Ultraviolet (UV) radiation has been widely studied for inactivating various species of microorganisms, including viruses. The most applicable UV light for viruses ranges from 200nm to 280nm in wavelength, i.e., UVC. More recently, the synergy of UVA light with UVC has been studied in disinfecting bacteria in polluted water. However, little attention has been paid to studying viral inactivation by coupled UVC and UVA LEDs. The necessity of such research is to find an effective and economical solution for the LEDs of these two bands. Along this track, we attempt to tackle two major challenges. The first is to find a suitable viral surrogate that can safely be used in ordinary labs. In this aspect, lentivirus is commonly used as a genetic vector and has been selected to surrogate RNA viruses. Another is to determine the effective dosage of the coupled UVC and UVA light. To this end, the surrogate lentivirus was irradiated by 280nm (UVC) LEDs, 365nm (UVA) LEDs, and their combination at various doses. Survival rates were detected to compare the efficacy of various options. Moreover, the viral RNA damage was detected by RT-qPCR to disclose the mechanism of viral death. The results have shown that for the same duration of irradiation, the effect of the full-power 280nm LEDs is equivalent to that of the half-power 280nm LEDs combined with a suitable radiant power of the 365nm LEDs. The observations have been further confirmed by the effect of damaging the viral RNA by either the 280nm or 365nm light. In conclusion, the experimental results provide clear evidence of alleviating the requirement of UVC LEDs in viral inactivation by substituting them partially with UVA LEDs.
RNA病毒在自然界中无处不在，其中许多可导致人类严重感染综合征，例如严重急性呼吸综合征冠状病毒2（SARS-CoV-2）病毒。紫外线（UV）辐射已被广泛研究用于灭活包括病毒在内的各种微生物。对病毒最适用的紫外线波长范围为200nm至280nm，即UVC。最近，已研究了UVA光与UVC协同作用对污水中细菌的消毒效果。然而，对于UVC和UVA发光二极管（LED）联合作用使病毒失活的研究却很少受到关注。此类研究的必要性在于找到一种针对这两个波段LED的有效且经济解决方案。沿着这条思路，我们试图应对两个主要挑战。第一个挑战是找到一种适合在普通实验室安全使用的病毒替代物。在这方面，慢病毒通常用作基因载体，已被选作RNA病毒的替代物。另一个挑战是确定UVC和UVA联合光的有效剂量。为此，用280nm（UVC）LED、365nm（UVA）LED及其不同剂量组合对替代慢病毒进行照射。检测存活率以比较各种方案的效果。此外，通过逆转录定量聚合酶链反应（RT-qPCR）检测病毒RNA损伤，以揭示病毒死亡机制。结果表明，在相同照射时间下，全功率280nm LED的效果等同于半功率280nm LED与合适辐射功率的365nm LED组合的效果。280nm或365nm光对病毒RNA的损伤作用进一步证实了这些观察结果。总之，实验结果提供了明确证据，表明通过部分用UVA LED替代UVC LED可减轻病毒灭活中对UVC LED的需求。
