摘要
【目的】研制一种叶酸受体修饰的CdTe/CdS量子点荧光探针并初步验证其靶向性。【方法】以巯基丁二酸(MSA)为稳定剂,采用水相合成法合成CdTe/CdS核壳型量子点。利用紫外分光光度计、荧光分光光度计、X线粉末衍射仪、透射电镜分别对其紫外吸收情况、光致发光性质、晶体结构、形貌进行表征。采用连接了叶酸的氨基聚乙二醇与CdTe/CdS量子点偶联,制备叶酸受体靶向的(FA-PEG-CdTe/CdS)量子点荧光探针。通过凝胶电泳和光谱分析鉴定偶联效果。在荧光倒置显微镜下观察已知细胞表面叶酸受体阳性的鼻咽癌细胞株HNE-1和人喉癌细胞株Hep-2及叶酸受体阴性的鼻咽癌细胞株CNE-2和FA-PEG-CdTe/CdS量子点探针的摄取情况。通过观察分析不同细胞被标记的情况去检验荧光探针的靶向性和特异性。【结果】以巯基丁二酸为稳定剂,当pH=10,物质的量比为n(Te2-):n(Cd2+):n(MSA)=1:10:10.5的条件下,随加热回流反应时间的延长,CdTe量子点的粒径不断增长,吸收光谱和光致发光谱不断红移。在反应10 min时获得了量子产率高达72.5%的CdTe量子点;X射线粉末衍射图显示出对应立方晶型CdTe的三个晶面(111),(220),(311),透射电子显微镜下呈近似球形,粒径分布较均匀,平均粒径约为3 nm(反应10 min)。琼脂糖凝胶电泳和荧光光谱分析证实CdTe/CdS量子点与PEG-FA成功偶联,荧光显微镜下显示出叶酸受体阳性的HNE-1、Hep-2被FA-PEG-CdTe/CdS量子点荧光探针特异性标记。【结论】CdTe量子点可作为新型的荧光标记材料,核壳型CdTe/CdS量子点与叶酸偶联后稳定性较好,FA-PEG-CdTe/CdS量子点荧光探针具有良好的靶向性,在高表达叶酸受体的肿瘤诊断和治疗方面具有良好的应用前景。
[Objective] To develop a CdTe/CdS quantum dots fluorescent probe （FA-PEG-CdTe/CdS） modified with folate receptor and to detect its targeting.[Methods] CdTe/CdS QD were synthesized in aqueous phase by using mercaptosuccinic acid （MSA） as stabilizer and linker.The spectral properties were investigated via fluorescence spectrophotometer and UV spectrophotometry.Crystal composition was determined via X-radial diffractometer.Morphology of the prepared QD was determined on a transmission electron microscopy （TEM）.The folate receptor targeting quantum dots fluorescent probe FA-PEG-CdTe/CdS was made by coupling CdTe/CdS QD with FA-PEG-NH2.The Coupling effect was evaluated by agarose gel electrophoresis and spectral analysis.The cellular uptake in FR-positive human nasopharyngeal carcinoma cells （HNE-1cells） and FR-negative human nasopharyngeal carcinoma cells （CNE-2 cell） for FA-PEG-CdTe/CdS was found by means of inverted fluorescence microscopy.We can test the targeting property and specificity by observing the mark situation of different cells which cultured in different medium.[Result] In the condition of pH =10,n（Te2＋）：n（Cd2-）：n（MSA） =1：10：10.5,with reaction time prolonging,the diameters of MSA-stabilized CdTe is increasing and the adsorption spectra and emission spectrum is constantly red shifting but the fluorescence quantum yield of CdTe QD is decreasing.The quantum yield of CdTe QD had reached 72.5% in the reaction of ten minutes.The XRD patterns of MSA-stabilized CdTe had proved the corresponding （111）,（220）,（311） lattice faces of cubic crystal CdTe.The picture of TEM show the CdTe particle size distribution is uniform and the average particle diameter is 3 nm （10 min）.The agarose gel electrophoresis and spectral analysis proved that CdTe/CdS-PEG-FA is Stable.From the result of inverted fluorescence microscopy,FR-positive HNE-1,Hep-2 can be specific marked by FA-PEG-CdTe/CdS.[Conclusion] CdTe quantum dots can be used as a new fluorescent marking material.
出处
《中山大学学报（医学科学版）》
CAS
CSCD
北大核心
2013年第3期331-338,共8页
Journal of Sun Yat-Sen University:Medical Sciences
基金
国家自然科学基金(21103052)
教育部高校博士点基金(20114433110001)
广东省自然科学基金(10251051501000001)
关键词
量子点
分子靶向
叶酸
CDTE
CDS
荧光探针
鼻咽癌
喉癌
quantum dots （QD）
molecular target folic acid （FA）
CdTe/CdS
fluorescent probe
nasopharyngeal carcinoma
laryngocarcinoma
