School of Public Health and Institute of Health and Environment, Seoul National University, Seoul, Republic of Korea.
Drug Chem Toxicol. 2010 Oct;33(4):357-66. doi: 10.3109/01480540903493507.
A safe alternative to the viral system used in gene therapy is a nonviral gene delivery system. Although polyethylenimine (PEI) and polyamidoamine (PAMAM) dendrimer are among the most promising gene-carrier candidates for efficient nonviral gene delivery, safety concerns regarding their toxicity remain. The aim of this study was to scrutinize the underlying mechanism of the cytotoxicity and genotoxicity of PEI (25 kDa) and PAMAM (G4). To our knowledge, this is the first study to explore the genotoxic effect of polymeric gene carriers. To evaluate cell death by PEI and PAMAM, we performed propidium-iodide staining and lactate-dehydrogenase release assays. The genotoxicity of the polymers was measured by comet assay and cytokinesis-block micronucleus assay. PEI- and PAMAM-treated groups induced both necrotic and apoptotic cell death. In the comet assay and micronuclei formation, significant increases in DNA damage were observed in both treatments. We conclude that PEI and PAMAM dendrimer can induce not only a relatively weak apoptotic and a strong necrotic effect, but also a moderate genotoxic effect.
一种替代病毒系统用于基因治疗的安全方法是非病毒基因传递系统。尽管聚乙烯亚胺（PEI）和聚酰胺-胺（PAMAM）树枝状大分子是最有前途的高效非病毒基因传递的基因载体候选物之一，但它们的毒性安全性问题仍然存在。本研究旨在深入研究 PEI（25 kDa）和 PAMAM（G4）的细胞毒性和遗传毒性的潜在机制。据我们所知，这是首次探索聚合物基因载体的遗传毒性效应的研究。为了评估 PEI 和 PAMAM 诱导的细胞死亡，我们进行了碘化丙啶染色和乳酸脱氢酶释放实验。通过彗星实验和胞质分裂微核实验来测量聚合物的遗传毒性。PEI 和 PAMAM 处理组诱导了坏死和凋亡细胞死亡。在彗星实验和微核形成中，两种处理均观察到 DNA 损伤明显增加。我们得出结论，PEI 和 PAMAM 树枝状大分子不仅可以诱导相对较弱的凋亡和较强的坏死作用，还可以诱导中等程度的遗传毒性作用。
