磁免疫结合单颗粒模式ICP-MS同时测定乳腺癌病人血清中的CEA与CA15-3

Detection of Carcinoembryonic Antigen and Carbohydrate Antigen 15-3 in Human Breast Cancer Serum Using Single Particle Mode ICP-MS Coupled with Magnetic Immunoassay

该文合成了氨基修饰的磁性纳米颗粒并将其与癌胚抗原(CEA)一抗和糖类抗原15-3(CA15-3)一抗偶联用提取靶标生物标志物,羧基功能化上转换纳米颗粒(UCNPs)和氨基功能化二氧化铈-二氧化硅纳米颗粒(CeO2-SiO2NPs)用于标记抗体,由于174Yb和140Ce的瞬态信号频率与UCNPs和CeO2-SiO2NPs浓度直接相关,可利用单颗粒ICP-MS产生的瞬态信号频率定量分析CEA和CA15-3,基于此建立了同时测定乳腺癌病人血清中CEA和CA15-3的单颗粒ICP-MS磁免疫分析方法。结果显示:在优化条件下,CEA和CA15-3分别在0.02~100 ng·mL^(-1)和0.05~50 U·mL^(-1)浓度范围内线性良好,相关系数(r2)分别为0.9940和0.9870;以3倍信噪比(S/N=3)计算得CEA和CA15-3的检出限(LOD)分别为0.0067 ng·mL^(-1)和0.0167 U·mL^(-1)。采用该方法在3名乳腺癌病人血清中均检出CEA和CA15-3,加标回收率分别为95.2%~98.9%和95.5%~97.2%,相对标准偏差(RSD)分别为3.0%~4.6%和3.4%~4.3%。实验结果与临床使用的化学发光免疫方法结果一致,方法可用于乳腺癌病人血清样品中CEA和CA15-3含量的测定。

Carcinoembryonic antigen(CEA)is a kind of glycoprotein that has been extensively investigated as a tumor marker for clinical diagnosis,which is routinely used as part of an individual's annual medical checkup in China.It is present in about 95%of all colon tumors and 50%of breast tumors and is also associated with ovarian carcinoma,lung cancer and other cancers.CEA is a preferred tumor marker to help predict outlook in patients with colorectal cancer.Breast cancer is the most widespread life-threatening cancer among women worldwide.It is a complex and heterogeneous disease composed of several subtypes with different morphological and clinical implications.One of the most important biomarkers for breast cancer is the carbohydrate antigen 15-3(CA15-3).The concentration of CA15-3 in blood serum could provide information from monitoring of therapy,which could also predict breast cancer recurrence after curative surgery.Hence,it is important to develop a highly sensitive analytical method for accurate and selective detection of CEA and CA15-3.Compared to one element tagging,the immunoassay of multi-elements can improve assay efficiency and reduce sample consumption.In this study,several immunoassay procedure parameters were examined,including effects of dwell time,concentrations of CeO2-SiO2NPs and UCNPs on the number of detection events.A new method for simultaneous determination of CEA and CA15-3 was developed using single particle inductively coupled plasma mass spectrometry(ICP-MS)coupled with magnetic immunoassay.Meanwhile,amino-modified magnetic nanoparticles were synthesized and conjugated with primary CEA antibody and primary CA15-3 antibody to extract the target biomarkers.The suspension solutions were separated with a permanent magnet.Single particles were directly introduced into ICP-MS with a custom,gas pressure-assisted sample introduction system.Carboxyl-functionalized up-conversion nanoparticles(UCNPs)and amino-functionalized cerium dioxide-silicon dioxide nanoparticles(CeO2-SiO2NPs)were employed to tag antibodies.The frequencies of transient signals of 174Yb and 140Ce were directly related to the concentrations of UCNPs and CeO2-SiO2NPs.CEA and CA15-3 could be quantified via the frequency of transient signal produced by single particle ICP-MS.Under the optimal conditions,the linear concentration ranges for CEA and CA15-3 were 0.02^(-1)00 ng·mL^(-1)and 0.05-50 U·mL^(-1),respectively.Their correlation coefficients were 0.9940 and 0.9870,respectively.The detection limits(LOD,S/N=3)of CEA and CA15-3 were 0.0067 ng·mL^(-1)and 0.0167 U·mL^(-1),respectively.The method was applied to the simultaneous detection of CEA and CA15-3 in human breast cancer serum with recoveries of 95.2%-98.9%and 95.5%-97.2%,and relative standard deviations(RSD)of 3.0%-4.6%and 3.4%-4.3%,respectively.