Preparation of peptide-conjugated quantum dots for tumor vasculature-targeted imaging
Preparation of peptide-conjugated quantum dots for tumor vasculature-targeted imaging
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DOI：
10.1038/nprot.2007.478
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发表时间：
2008-01-01
期刊：
影响因子：
14.8
通讯作者：
Chen, Xiaoyuan
中科院分区：
文献类型：
--
作者：
Cai, Weibo;Chen, Xiaoyuan
为了充分利用量子点（QDs）独特的光学特性并加快未来近红外荧光（NIRF）成像应用，量子点需要在系统给药后有效、特异性和可靠地定向到特定器官或疾病部位。最近，我们报道了在小动物模型中使用肽偶联量子点对肿瘤血管标记物进行无创NIRF成像。在本协议中，我们描述了使用市售的peg包被量子点和精氨酸-甘氨酸-天冬氨酸（RGD）肽制备这种肽偶联量子点的详细过程。硫代RGD肽通过异双功能连接剂4-马来酰亚胺丁酸n -琥珀酰亚胺酯与量子点偶联。在荷瘤小鼠体内显像前，以I-125-echistatin为放射配体，进行竞争性细胞结合实验，并进行活细胞染色，证实RGD肽成功附着于QD表面。一般来说，QD偶联和肽偶联QD的体外验证可以在1-2天内完成；根据实验设计，体内成像还需要1-2天。
To take full advantage of the unique optical properties of quantum dots (QDs) and expedite future near-infrared fluorescence (NIRF) imaging applications, QDs need to be effectively, specifically and reliably directed to a specific organ or disease site after systemic administration. Recently, we reported the use of peptide-conjugated QDs for non-invasive NIRF imaging of tumor vasculature markers in small animal models. In this protocol, we describe the detailed procedure for the preparation of such peptide-conjugated QDs using commercially available PEG-coated QDs and arginine-glycine-aspartic acid (RGD) peptides. Conjugation of the thiolated RGD peptide to the QDs was achieved through a heterobifunctional linker, 4-maleimidobutyric acid N-succinimidyl ester. Competitive cell binding assay, using I-125-echistatin as the radioligand, and live cell staining were carried out to confirm the successful attachment of the RGD peptides to the QD surface before in vivo imaging of tumor- bearing mice. In general, QD conjugation and in vitro validation of the peptide-conjugated QDs can be accomplished within 1-2 d; in vivo imaging will take another 1-2 d depending on the experimental design.