Mansur Herman S, Mansur Alexandra A P, Soriano-Araújo Amanda, Lobato Zélia I P, de Carvalho Sandhra M, Leite Maria de Fatima
Center of Nanoscience, Nanotechnology, and Innovation-CeNano(2)I, Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais, UFMG, Av. Presidente Antônio Carlos, 6627, Belo Horizonte, MG 31.270-901, Brazil.
Center of Nanoscience, Nanotechnology, and Innovation-CeNano(2)I, Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais, UFMG, Av. Presidente Antônio Carlos, 6627, Belo Horizonte, MG 31.270-901, Brazil.
Mater Sci Eng C Mater Biol Appl. 2015;52:61-71. doi: 10.1016/j.msec.2015.03.022. Epub 2015 Mar 22.
Cancer remains one of the world's most devastating diseases with millions of fatalities and new cases every year. In this work, we attempted to develop a facile "enzyme-free" fluoroimmunoassay based on the novel nanoconjugates composed of CdS quantum dots (QDs) as the fluorescent inorganic core and an antibody-modified polysaccharide as the organic shell, modeling their possible application for the in vitro diagnosis of non-Hodgkin lymphoma (NHL) cancer. Chitosan was conjugated with an anti-CD20 polyclonal antibody (pAbCD20) by the formation of covalent amide bonds. In the sequence, these chitosan-antibody conjugates were utilized as direct ligands for the surface biofunctionalization of CdS QDs (CdS/chitosan-pAbCD20) using a single-step colloidal process in aqueous medium at room temperature. The most relevant physico-chemical properties of these nanoconjugates were assessed by morphological and spectroscopic techniques. The results indicated that CdS nanocrystals were produced with an average diameter of 2.5 nm and with cubic zinc blende crystalline nanostructure. The CdS-immunoconjugates (CdS/chitosan-pAbCD20) presented colloidal hydrodynamic diameter (HD) of 15.0 ± 1.2n m. In addition, the results evidenced that the "enzyme-free" QD-linked immunosorbent assay (QLISA) was effective for the in vitro detection against the antigen CD20 (aCD20) based on fluorescent behavior of the CdS nanoconjugates. Moreover, the CdS-immunoconjugates were successfully used for fluorescence bioimaging of NHL cancer cells. Finally, the cell viability results using different cell cultures based on LDH, MTT and Resazurin bio-assays have demonstrated no cytotoxicity of the new CdS-chitosan bioconjugates relative to the standard controls. Thus, CdS conjugates may offer a promising platform for the future development of in vitro and in vivo applications for the detection and diagnosis of NHL cancer cells.
癌症仍然是世界上最具毁灭性的疾病之一，每年有数百万例死亡病例和新发病例。在这项工作中，我们试图基于由硫化镉量子点（QDs）作为荧光无机核心和抗体修饰的多糖作为有机外壳组成的新型纳米共轭物，开发一种简便的“无酶”荧光免疫测定法，模拟其在非霍奇金淋巴瘤（NHL）癌症体外诊断中的可能应用。壳聚糖通过形成共价酰胺键与抗CD20多克隆抗体（pAbCD20）共轭。随后，在室温下于水性介质中通过单步胶体过程，将这些壳聚糖 - 抗体共轭物用作硫化镉量子点（CdS /壳聚糖 - pAbCD20）表面生物功能化的直接配体。通过形态学和光谱技术评估了这些纳米共轭物最相关的物理化学性质。结果表明，制备的硫化镉纳米晶体平均直径为2.5nm，具有立方闪锌矿晶体纳米结构。CdS免疫共轭物（CdS /壳聚糖 - pAbCD20）的胶体流体动力学直径（HD）为15.0±1.2nm。此外，结果证明基于CdS纳米共轭物的荧光行为，“无酶”量子点连接免疫吸附测定法（QLISA）对体外检测抗原CD20（aCD20）有效。此外，CdS免疫共轭物成功用于NHL癌细胞的荧光生物成像。最后，基于乳酸脱氢酶（LDH）、噻唑蓝（MTT）和刃天青生物测定法的不同细胞培养物的细胞活力结果表明，相对于标准对照，新的CdS - 壳聚糖生物共轭物没有细胞毒性。因此，CdS共轭物可能为未来开发用于检测和诊断NHL癌细胞的体外和体内应用提供一个有前景的平台。
