Optometry and Vision Science, University of Waterloo, Waterloo, Canada.
Centre for Ocular Research & Education, Optometry and Vision Science, University of Waterloo, Waterloo, Canada.
Cutan Ocul Toxicol. 2021 Jun;40(2):78-84. doi: 10.1080/15569527.2021.1902339. Epub 2021 Mar 26.
Benzalkonium chloride (BAK) is a widely used disinfectant and preservative which is effective against a wide range of viruses (e.g. SARS-CoV and SARS-CoV-2), bacteria and fungi. However, it is toxic to the eye and skin. This study investigated the neutralization of BAK using ultraviolet C (UVC) radiation as an effort to reduce BAK toxicity potential.
BAK solutions were irradiated with a germicidal UVC lamp at various doses. Human corneal epithelial cells (HCEC) were then exposed to the UVC-irradiated BAK solutions for 5 minutes. After exposure, the cultures were assessed for metabolic activity using PrestoBlue; for cell viability using confocal microscopy with viability dyes; and for tight junction proteins using immunofluorescence staining for zonula occludens (ZO)-1.
UVC radiation reduced BAK toxicity on cell metabolic activity in a dose-dependent manner. When the solution depth of BAK was 1.7 mm, the UVC doses needed to completely neutralize the toxicity of BAK 0.005% and 0.01% were 2.093 J/cm and 8.374 J/cm, respectively. The cultures treated with UVC-neutralized BAK showed similar cell metabolic activity and cell viability to those treated with phosphate buffered saline (PBS) ( = 0.806 ∼ 1.000). The expression of ZO-1 was greatly disturbed by untreated BAK; in contrast, ZO-1 proteins were well maintained after exposure to UVC-neutralized BAK.
Our study demonstrates that the cell toxicity of BAK can be neutralized by UVC radiation, which provides a unique way of detoxifying BAK residues. This finding may be of great value in utilizing the antimicrobial efficacy of BAK (e.g. fighting against SARS-CoV-2) while minimizing its potential hazards to human health and the environment.
苯扎氯铵（BAK）是一种广泛使用的消毒剂和防腐剂，对多种病毒（如 SARS-CoV 和 SARS-CoV-2）、细菌和真菌均有效。但是，它对眼睛和皮肤具有毒性。本研究旨在使用紫外线 C（UVC）辐射来中和 BAK，以降低 BAK 的毒性。
用杀菌 UVC 灯对 BAK 溶液进行不同剂量的照射。然后，将人类角膜上皮细胞（HCEC）暴露于经 UVC 照射的 BAK 溶液中 5 分钟。暴露后，使用 PrestoBlue 评估细胞代谢活性；使用活细胞染料的共聚焦显微镜评估细胞活力；使用免疫荧光染色法评估紧密连接蛋白 ZO-1 的表达。
UVC 辐射以剂量依赖性方式降低 BAK 对细胞代谢活性的毒性。当 BAK 溶液深度为 1.7mm 时，完全中和 BAK 0.005%和 0.01%毒性所需的 UVC 剂量分别为 2.093 J/cm 和 8.374 J/cm。用 UVC 中和的 BAK 处理的培养物与用磷酸盐缓冲盐水（PBS）处理的培养物（=0.806∼1.000）具有相似的细胞代谢活性和细胞活力。未经处理的 BAK 极大地扰乱了 ZO-1 的表达；相比之下，暴露于 UVC 中和的 BAK 后，ZO-1 蛋白得到很好的维持。
我们的研究表明，BAK 的细胞毒性可以通过 UVC 辐射中和，这为解毒 BAK 残留提供了一种独特的方法。这一发现可能对利用 BAK 的抗菌功效（例如对抗 SARS-CoV-2）具有重要价值，同时最大限度地降低其对人类健康和环境的潜在危害。
