Chen Jian-tao, Sun Hua-qin, Wang Wei-liang, Xu Wen-ming, He Qin, Shen Shun, Qian Jun, Gao Hui-le
Key Laboratory of Drug Targeting and Drug Delivery Systems, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
Joint Laboratory of Reproductive Medicine, Sichuan University-The Chinese University of Hong Kong, West China Second University Hospital, Sichuan University, Chengdu 610041, China.
Acta Pharmacol Sin. 2015 Nov;36(11):1349-55. doi: 10.1038/aps.2015.100. Epub 2015 Oct 12.
Carbonaceous dots (CDs), which have been used for diagnosis, drug delivery and gene delivery, are accumulated in heart at high concentrations. To improve their biocompatibility, polyethylene glycol-modified CDs (PEG-CDs) were prepared. In this study we compared the cardiac toxicity of CDs and PEG-CDs in mouse and zebrafish models.
Mice were intravenously treated with CDs (size: 4.9 nm, 5 mg·kg(-1)·d(-1)) or PEG-CDs (size: 8.3 nm, 5 mg·kg(-1)·d(-1)) for 21 d. Their blood biochemistry indices, ECG, and histological examination were examined for evaluation of cardiac toxicity. CDs or PEG-CDs was added in incubator of cmlc2 transgenic Zebrafish embryos at 6 hpf, and the shape and size of embryos' hearts were observed at 48 hpf using a fluorescent microscope. Furthermore, whole-mount in situ hybridization was used to examine the expression of early cardiac marker gene (clml2) at 48 hpf.
Administration of CDs or PEG-CDs in mice caused mild, but statistically insignificant reduction in serum creatine kinase (CK) and lactate dehydrogenase (LDH) levels detected at 7 d, which were returned to the respective control levels at 21 d. Neither CDs nor PEG-CDs caused significant changes in the morphology of heart cells. Administration of CDs, but not PEG-CDs, in mice caused marked increase of heart rate. Both CDs and PEG-CDs did not affect other ECG parameters. In the zebrafish embryos, addition of CDs (20 μg/mL) caused heart development delay, whereas addition of CDs (80 μg/mL) led to heart malformation. In contrast, PEG-CDs caused considerably small changes in heart development, which was consistent with the results from the in situ hybridization experiments.
CDs causes greater cardiac toxicity, especially regarding heart development. Polyethylene glycol modification can attenuate the cardiac toxicity of CDs.
已用于诊断、药物递送和基因递送的碳点（CDs）会在心脏中高浓度蓄积。为提高其生物相容性，制备了聚乙二醇修饰的碳点（PEG-CDs）。在本研究中，我们在小鼠和斑马鱼模型中比较了CDs和PEG-CDs的心脏毒性。
小鼠静脉注射CDs（尺寸：4.9 nm，5 mg·kg⁻¹·d⁻¹）或PEG-CDs（尺寸：8.3 nm，5 mg·kg⁻¹·d⁻¹），持续21天。检测其血液生化指标、心电图和组织学检查以评估心脏毒性。在受精后6小时（hpf）将CDs或PEG-CDs添加到cmlc2转基因斑马鱼胚胎的培养箱中，并在48 hpf使用荧光显微镜观察胚胎心脏的形状和大小。此外，采用整胚原位杂交技术检测48 hpf时早期心脏标记基因（clml2）的表达。
在小鼠中给予CDs或PEG-CDs导致第7天检测到的血清肌酸激酶（CK）和乳酸脱氢酶（LDH）水平出现轻度但无统计学意义的降低，在第21天时恢复到各自的对照水平。CDs和PEG-CDs均未引起心脏细胞形态的显著变化。在小鼠中给予CDs而非PEG-CDs导致心率显著增加。CDs和PEG-CDs均未影响其他心电图参数。在斑马鱼胚胎中，添加CDs（20 μg/mL）导致心脏发育延迟，而添加CDs（80 μg/mL）导致心脏畸形。相比之下，PEG-CDs对心脏发育的影响较小，这与原位杂交实验的结果一致。
CDs具有更大的心脏毒性，尤其是在心脏发育方面。聚乙二醇修饰可减弱CDs的心脏毒性。
