月球和火星尘埃对人体有害吗？

　　

月亮上到处覆盖着几十亿年来太空撞击造成的尘土。由于月球重力小，加上静电，扬尘弥漫不去。1972年，阿波罗号登上月球。宇航员被厚厚的尘埃所困扰，有些甚至出现了过敏的充血症状。暴露在月尘下对眼睛、呼吸道和皮肤产生了刺激，这暗示月尘可能是人类健康的潜在危险。未来若想继续探访月球、火星及其他目的地，则必须评估外星粉尘的健康风险。

为此，德国不莱梅雅各布大学（Jacobs University）细胞生物学与皮肤再生方面的专家Klaudia Brix领导的小组最近开展了一项研究，利用罗氏诊断公司的xCELLigence系统，为月尘对人类健康的影响提供了大量的信息。该研究论文发表在4月1日的《Advances in Space Research》上。

在此项研究中，研究小组评估了外星粉尘对哺乳动物皮肤的影响。他们使用了模拟月球或火星土壤的尘埃，让HaCaT角质形成细胞和CHO-K1成纤维细胞在尘埃下暴露不同时间。他们特别关注了细胞形态和细胞活力的变化。之所以使用角质形成细胞和成纤维细胞，是因为人的皮肤保护机体免受有害物质，也是伤口愈合的地方。

他们利用罗氏的xCELLigence系统不断监测细胞阻抗，来进行实时、无标记的细胞毒性测定，同时开展了罗氏的MTT分析。此外，他们也进行了肌动蛋白骨架的鬼笔环肽染色以及碘化丙啶吸收分析，来研究细胞结构的完整性。

通过研究两个细胞系的各种功能，研究人员鉴定出两种类型的模拟月尘。暴露在模拟月尘之下，HaCaT细胞增殖被抑制，且划痕后单层角质形成细胞的再生延迟。这暗示了外星粉尘暴露对伤口愈合的负面影响，那么在计划下一次探月行动时，也许有必要增加一项风险评估研究。

这些重要的结果将帮助科学家组织适当的安全措施，使得下一次执行月球或火星探索任务时，当人暴露在这些尘埃下，它们对人类健康的风险能降至最低。

xCELLigence RTCA仪器无需外部标记，通过测量电阻来持续监控细胞反应。微电极整合在特殊设计的组织培养E-Plate的底部，来测量细胞状态的改变，并提供精确的定量信息，包括细胞数量、细胞粘附、细胞活力和细胞形态。对细胞响应度的持续阻抗监控让研究人员能准确地找出重要的实验时间点，来进行更详细的下游分析。此产品曾被生物通评为“2008年度生命科学十大创新产品”。（生物通 余亮）

点击此处索取xCELLigence的详细资料

原文摘要：

Effects of lunar and mars dust simulants on HaCaT keratinocytes and CHO-K1 fibroblasts

Advances in Space Research  Volume 47, Issue 7, 1 April 2011, Pages 1200-1213

摘要：
Exposure to lunar dust during Apollo missions resulted in occasional reports of ocular, respiratory and dermal irritations which showed that lunar dust has a risk potential for human health. This is caused by its high reactivity as well as its small size, leading to a wide distribution also inside habitats. Hence, detailed information regarding effects of extraterrestrial lunar dusts on human health is required to best support future missions to moon, mars or other destinations. In this study, we used several methods to assess the specific effects of extraterrestrial dusts onto mammalian skin by exposing HaCaT keratinocytes and CHO-K1 fibroblasts to dusts simulating lunar or mars soils. These particular cell types were chosen because the skin protects the human body from potentially harmful substances and because a well orchestrated program ensures proper wound healing. Keratinocytes and fibroblasts were exposed to the dusts for different durations of time and their effects on morphology and viability of the cells were determined. Cytotoxicity was measured using the MTT assay and by monitoring culture impedance, while phalloidin staining of the actin cytoskeleton was performed to address structural integrity of the cells which was also investigated by propidium iodide intake. It was found that the effects of the two types of dust simulants on the different features of both cell lines varied to a considerable extent. Moreover, proliferation of HaCaT keratinocytes, as analyzed by Ki67 labeling, was suppressed in sub-confluent cultures exposed to lunar dust simulant. Furthermore, experimental evidence is provided for a delay in regeneration of keratinocyte monolayers from scratch-wounding when exposed to lunar dust simulant. The obtained results will facilitate further investigations of dust exposure during wound healing and will ease risk assessment studies e.g., for lunar lander approaches. The investigations will help to determine safety measures to be taken during extraterrestrial expeditions in order to minimize risks to human health associated with exposure of human skin to dust contaminants.