We studied the genotoxicity and cellular uptake of nanosized (<50 nm) and fine (<10 μm) copper oxide (CuO) particles in vitro in human bronchial epithelial (BEAS-2B) cells. In addition, the effect of dispersing the particles using bovine serum albumin (BSA) on DNA damage induction was investigated. DNA damage was assessed by the alkaline comet (single cell gel electrophoresis) assay after 3-h, 6-h and 24-h exposures. The cytokinesis-block micronucleus assay was applied to study chromosome damage. Both fine- and nanosized CuO particles induced a dose-dependent increase in DNA damage at all timepoints tested. However, nanosized CuO damaged DNA at lower doses and higher levels compared with fine CuO. Dispersing the nanoparticles in the presence of BSA (0.6 mg/mL) resulted in a small and inconsistent decrease in DNA damage compared with dispersions in serum-free cell culture medium only. CuO nanoparticles induced a clear dose-dependent increase in micronucleated cells at doses that strongly increased cytostasis and were markedly cytotoxic at 24 and 48 h. Fine CuO showed a slight induction of micronuclei. Hyperspectral microscopy indicated a substantial cellular uptake of both types of particles after a 3-h exposure to a dose of 20 μg/cm². The number of particles internalized by the cells was higher for nanosized than fine CuO, as quantified by the frequency of spectral matches in the total cell area and by the number of spectrally matched visible particles or agglomerates per cell. The particle uptake was limited by particle size. The stronger genotoxic activity of nanosized than fine CuO particles is likely to derive from the higher cellular uptake and more effective intracellular dissolution of nanoparticles.

我们在体外研究了纳米级 (<50 nm) 和精细 (<10 μm) 氧化铜 (CuO) 颗粒的遗传毒性和细胞吸收在人支气管上皮 (BEAS-2B) 细胞中。此外，研究了使用牛血清白蛋白 (BSA) 分散颗粒对 DNA 损伤诱导的影响。在暴露 3 小时、6 小时和 24 小时后，通过碱性彗星（单细胞凝胶电泳）测定法评估 DNA 损伤。胞质分裂阻断微核试验用于研究染色体损伤。在所有测试时间点，精细和纳米尺寸的 CuO 颗粒均诱导 DNA 损伤的剂量依赖性增加。然而，与精细的 CuO 相比，纳米尺寸的 CuO 以较低剂量和较高水平损伤 DNA。与仅在无血清细胞培养基中分散相比，在 BSA (0.6 mg/mL) 存在下分散纳米颗粒导致 DNA 损伤小幅且不一致的减少。CuO 纳米颗粒在显着增加细胞停滞的剂量下诱导微核细胞明显的剂量依赖性增加，并且在 24 和 48 小时时具有显着的细胞毒性。细的CuO显示出微核的轻微诱导。高光谱显微镜显示，在暴露于 20 μg/cm 的剂量 3 小时后，两种类型的颗粒均被大量细胞吸收² . 纳米尺寸的细胞内化的颗粒数量高于细小的 CuO，这通过总细胞面积中的光谱匹配频率和每个细胞的光谱匹配可见颗粒或团聚体的数量来量化。颗粒吸收受到颗粒尺寸的限制。纳米尺寸比精细 CuO 颗粒更强的基因毒性活性可能源于纳米颗粒更高的细胞摄取和更有效的细胞内溶解。