Abstract

Purpose

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.

Methods

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.

Results

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/cm² and 8.374 J/cm², respectively. The cultures treated with UVC-neutralized BAK showed similar cell metabolic activity and cell viability to those treated with phosphate buffered saline (PBS) (p = 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.

Conclusions

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.

中文翻译：

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使用 UVC 辐射中和眼睛和皮肤刺激性苯扎氯铵

摘要

目的

苯扎氯铵 (BAK) 是一种广泛使用的消毒剂和防腐剂，可有效对抗多种病毒（例如 SARS-CoV 和 SARS-CoV-2）、细菌和真菌。然而，它对眼睛和皮肤有毒。本研究调查了使用紫外线 C (UVC) 辐射来中和 BAK，以努力降低 BAK 的毒性潜力。

方法

用不同剂量的杀菌 UVC 灯照射 BAK 溶液。然后将人角膜上皮细胞 (HCEC) 暴露于 UVC 照射的 BAK 溶液中 5 分钟。暴露后，使用 PrestoBlue 评估培养物的代谢活性；使用带有活力染料的共聚焦显微镜检测细胞活力；和使用免疫荧光染色封闭小带 (ZO)-1 的紧密连接蛋白。

结果

UVC 辐射以剂量依赖性方式降低 BAK 对细胞代谢活动的毒性。当 BAK 溶液深度为 1.7 mm 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 ²和 8.374 J/cm ²。用 UVC 中和的 BAK 处理的培养物显示出与用磷酸盐缓冲盐水 (PBS) 处理的那些相似的细胞代谢活性和细胞活力 ( p  = 0.806 ∼ 1.000)。未经处理的BAK严重干扰ZO-1的表达；相比之下，ZO-1 蛋白在暴露于 UVC 中和的 BAK 后保持良好。

结论

我们的研究表明，UVC 辐射可以中和 BAK 的细胞毒性，这提供了一种独特的 BAK 残留解毒方式。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，同时最大限度地减少其对人类健康和环境的潜在危害。