CY7-SE (Cyanine7 Succinimidyl Ester) is a fluorescent dye derived from CY7. CY7-SE can directly react covalently with the amino groups (-NH₂) of biomolecules such as proteins and antibodies, without the need for additional coupling agents (Ex=747nm, Em=774nm). CY7 is a fundamental lipophilic cyanine dye. Due to CY7 absorption in the near-infrared region, CY7 has a very low background, CY7 is the most intense and stable long-wavelength dye. CY7 is particularly suitable for in vivo imaging in small animals as an alternative to radioactive elements. However, the molecular structure of CY7 contains a positively charged mesomeric ion structure, which requires modification through carboxyl groups or other chemical modifications to enable covalent binding with biomolecules[1]. CY7-SE, on the other hand, is derived from CY7 by introducing an active ester group (-NHS), which allows CY7-SE to directly label biomacromolecules containing amino groups, including antibodies, peptides, and liposomes[2]. For example, the ovarian cancer-related antibody OC183B2 labeled with CY7-SE can clearly visualize ovarian cancer cells in real-time near-infrared fluorescence imaging[3]. Additionally, D-mannosamine labeled with CY7-SE (Cy7-DM) can bind to the mannose receptors on the surface of tumor-associated macrophages (TAMs), enabling the observation of TAM aggregation in tumor tissues through near-infrared fluorescence imaging[4].
Reference:
[1] LI Y, ZHOU Y, YUE X, et al. Cyanine Conjugate-Based Biomedical Imaging Probes [J]. Adv Healthc Mater, 2020, 9(22): e2001327.
[2] ZHANG H, YAN C, LI H, et al. Rational Design of Near-Infrared Cyanine-Based Fluorescent Probes for Rapid In Vivo Sensing Cysteine [J]. ACS Appl Bio Mater, 2021, 4(3): 2001-2008.
[3] ZHANG C, LING X, GUO Y, et al. Evaluation of COC183B2 antibody targeting ovarian cancer by near-infrared fluorescence imaging [J]. Chin J Cancer Res, 2019, 31(4): 673-685.
[4] JIANG C, CAI H, PENG X, et al. Targeted Imaging of Tumor-Associated Macrophages by Cyanine 7-Labeled Mannose in Xenograft Tumors [J]. Mol Imaging, 2017, 16(1536012116689499.
CY7-SE（Cyanine7 Succinimidyl Ester）是一种由CY7衍生的荧光染料，可直接与生物分子（如蛋白质、抗体）的氨基（-NH₂）发生共价反应，无需额外偶联试剂(Ex=747nm, Em=774nm)。CY7是基础的脂溶性花菁染料，由于Cy7的吸收在近红外区背景非常低，是荧光强度最高、最稳定的长波长染料。特别适合于活体小动物体内成像代替放射性元素。但CY7分子结构中含有一个正电荷的介离子结构，需要通过羧基或其他化学修饰才能与生物分子共价结合[1]。CY7-SE则是在CY7的基础上引入了活性酯基团（-NHS），可直接用于标记含氨基的生物大分子，包括抗体、多肽和脂质体等[2]。CY7-SE标记的卵巢癌相关抗体OC183B2，可将卵巢癌细胞清晰的呈现在实时近红外荧光成像中[3]。使用CY7-SE标记D-甘露糖胺（Cy7-DM）与肿瘤相关巨噬细胞（TAM）表面的甘露糖受体结合，可在近红外荧光成像中观察肿瘤相关巨噬细胞在肿瘤组织中的聚集情况[4]。