cNGR功能化金纳米粒子探针在乳腺癌血管生成CT成像中的应用

Application of cNGR functionalized gold nanoparticle probe in CT imaging of breast cancer angiogenesis

目的 制备聚乙二醇/环形天门冬酰胺酰-甘氨酰-精氨酸功能化的金纳米粒子（GNPs-PEG@cNGR），并评估其用于乳腺癌血管生成CT成像的效果。 方法 通过柠檬酸钠一步还原氯金酸的方法合成GNPs，巯基化的PEG和半胱氨酸更改的cNGR分别通过硫金键（Au—S）偶联到GNPs表面。采用透射电子显微镜、Zeta电位/水合粒径仪、傅里叶转换红外光谱仪等仪器对GNPs-PEG@cNGR进行表征。选取氨肽酶N（APN/CD13）阳性的人脐静脉内皮细胞（HUVEC）和人肝癌细胞（HepG2）分别研究GNPs-PEG@cNGR的摄取和CT成像效果。构建荷4T1乳腺癌BALB/c小鼠模型，研究GNPs-PEG@cNGR对小鼠体内肿瘤血管生成的CT成像效果，并检测其生物相容性。 结果 成功构建了靶向血管生成的特异性CT分子探针GNPs-PEG@cNGR。该探针呈球状，水合粒径为（35．7±1．0） ｎM，Zeta电位为（-13.54±1.12） mV，且具有良好的稳定性和生物相容性。GNPs-PEG@cNGR具有良好的CT成像效果，并可特异性靶向CD13阳性的HUVEC和HepG2细胞。荷4T1乳腺癌小鼠体内肿瘤CT成像结果显示，GNPs-PEG@cNGR注射后可特异性富集到肿瘤组织部位，GNPs-PEG@cNGRz组小鼠肿瘤部位CT值高于GNPs-PEG组，其差异具有统计学意义（P〈0.05）。 结论 GNPs-PEG@cNGR可特异性靶向CD13阳性细胞，可作为CT对比剂用于肿瘤血管生成成像。

Objective To prepare polyethylene glycol/cyclic asparagines-glycine-arginine functionalized gold nanoparticles（GNPs-PEG@cNGR）and evaluate their effectiveness in CT imaging of breast cancer angiogenesis.Methods The GNPs were synthesized by one-step reduction of chloroauric acid by sodium citrate.The thiolated PEG and cysteine-modified cNGR were coupled to the surface of GNPs through Au-S bonds,respectively.The GNPs-PEG@cNGR was characterized by transmission electron microscopy,Zeta potential/hydration particle size analyzer,and Fourier transform infrared spectrometer.The uptake and CT imaging effect of GNPs-PEG@cNGR were assessed by human umbilical vein endothelial cells（HUVEC）and human hepatoma cells（HepG2）positively expressed for aminopeptidase N（APN/CD13）.The in vivo CT imaging effects on tumor angiogenesis and biocompatibility in mice of GNPs-PEG@cNGR were studied by BALB/c mouse model of 4T1 breast cancer.Results A specific CT molecular probe,i.e.GNPs-PEG@cNGR,was successfully constructed,which can target angiogenesis.The probe was spherical,with a hydration particle size of（35.7±1.0）nm and a Zeta potential of（-13.54±1.12）mV,and had good stability and biocompatibility.The GNPs-PEG@cNGR has good CT imaging results and can specifically target CD13-positive HUVEC and HepG2 cells.The CT imaging results in 4T1 breast cancer mice indicated that GNPs-PEG@cNGR could be specifically enriched in the tumor tissue after injection.The CT value of tumors in GNPs-PEG@cNGRz group was higher than that of GNPs-PEG group,and the difference was statistically significant（P〈0.05）.Conclusions GNPs-PEG@cNGR can specifically target CD13 positive cells and can be used as a CT contrast agent for imaging tumor angiogenesis.