Laboratorium voor Cellulaire Genetica, Department of Biology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
Mutagenesis. 2011 Jan;26(1):185-91. doi: 10.1093/mutage/geq088.
The issue of appropriate testing strategies has been raised for the genotoxicity assessment of nanomaterials. Recently, efforts have been made to evaluate the adequacy of Organisation for Economic Co-operation and Development-standardised tests to assess the genotoxicity of nanomaterials. The aim of this review was to examine whether the current guideline for the in vitro micronucleus (MN) assay is applicable for testing nanomaterials. From a Pubmed literature search, 21 available studies were identified for analysis. We reviewed all protocols used for testing nanomaterials with the in vitro MN assay. All studies were categorised based on the particle type and size. Different aspects of the protocols were evaluated such as the exposure (duration and doses), the cytochalasin-B treatment, serum levels and cytotoxicity assessment. Sixteen of the 21 studies demonstrated increased frequencies of MN. Some recommendations regarding the protocol were formulated to maximise sensitivity and avoid false negatives. Determination of the cellular dose was advised for a better interpretation of MN frequency results. The level of serum can modulate the cellular response, therefore the serum percentage used should enable cell growth and proliferation and a maximal sensitivity of the assay. Furthermore, different types of cytochalasin-B treatment were used, co-treatment, post-treatment and delayed co-treatment. In order to avoid decreased cellular uptake as a consequence of actin inhibition, post-treatment or delayed co-treatment is suggested. Exposure during mitosis should be recommended to allow contact with the chromatin or mitotic apparatus for nanomaterials that are unable to cross the nuclear membrane. With these adaptations, the in vitro MN assay can be recommended for genotoxicity testing of nanomaterials.
对于纳米材料的遗传毒性评估，已经提出了适当的测试策略问题。最近，人们努力评估经济合作与发展组织标准化测试是否足以评估纳米材料的遗传毒性。本综述的目的是检查目前用于体外微核（MN）测定的指南是否适用于纳米材料的测试。通过 Pubmed 文献检索，确定了 21 项可用于分析的现有研究。我们审查了所有使用体外 MN 测定法测试纳米材料的方案。根据颗粒类型和大小对所有研究进行了分类。评估了方案的不同方面，例如暴露（持续时间和剂量）、细胞松弛素-B 处理、血清水平和细胞毒性评估。21 项研究中的 16 项显示 MN 频率增加。针对方案制定了一些建议，以提高敏感性并避免假阴性。建议确定细胞剂量，以便更好地解释 MN 频率结果。血清水平可以调节细胞反应，因此应使用允许细胞生长和增殖并使测定具有最大灵敏度的血清百分比。此外，还使用了不同类型的细胞松弛素-B 处理，包括共处理、后处理和延迟共处理。为避免由于肌动蛋白抑制而导致细胞摄取减少，建议进行后处理或延迟共处理。建议在有丝分裂期间进行暴露，以使无法穿过核膜的纳米材料与染色质或有丝分裂装置接触。通过这些适应，体外 MN 测定可推荐用于纳米材料的遗传毒性测试。
