A Lipopeptide-Based αvβ₃ Integrin-Targeted Ultrasound Contrast Agent for Molecular Imaging of Tumor Angiogenesis

Fei Yan; Xiuxia Xu; Yihan Chen; Zhiting Deng; Hongmei Liu; Jianrong Xu; Jie Zhou; Guanghong Tan; Junru Wu; Hairong Zheng

doi:10.1016/j.ultrasmedbio.2015.05.023

A Lipopeptide-Based αvβ₃ Integrin-Targeted Ultrasound Contrast Agent for Molecular Imaging of Tumor Angiogenesis

Ultrasound Med Biol. 2015 Oct;41(10):2765-73. doi: 10.1016/j.ultrasmedbio.2015.05.023. Epub 2015 Jul 10.

Authors

Fei Yan¹, Xiuxia Xu², Yihan Chen³, Zhiting Deng⁴, Hongmei Liu⁵, Jianrong Xu², Jie Zhou⁶, Guanghong Tan⁷, Junru Wu⁸, Hairong Zheng⁹

Affiliations

¹ Department of Ultrasonography, Third Affiliated Hospital of Southern Medical University, Guangzhou, China; Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
² School of Life Science and Engineering, Southwest University of Science and Technology, Sichuan, Mianyang, China.
³ Department of Ultrasonography, Third Affiliated Hospital of Southern Medical University, Guangzhou, China.
⁴ Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
⁵ Department of Ultrasonography, Third Affiliated Hospital of Southern Medical University, Guangzhou, China. Electronic address: [email protected].
⁶ Department of Echocardiography, Clinical Center of Reproductive Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
⁷ Hainan Provincial Key Laboratory of Tropical Medicine, Hainan Medical College, Haikou, China.
⁸ Department of Physics, University of Vermont, Burlington, Vermont, USA.
⁹ Department of Ultrasonography, Third Affiliated Hospital of Southern Medical University, Guangzhou, China; Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China. Electronic address: [email protected].

PMID: 26166460
DOI: 10.1016/j.ultrasmedbio.2015.05.023

Abstract

The design and fabrication of targeted ultrasound contrast agents are key factors in the success of ultrasound molecular imaging applications. Here, we introduce a transformable αvβ3 integrin-targeted microbubble (MB) by incorporation of iRGD-lipopeptides into the MB membrane for non-invasive ultrasound imaging of tumor angiogenesis. First, the iRGD-lipopeptides were synthesized by conjugating iRGD peptides to distearoylphosphatidylethanolamine-polyethylene glycol 2000-maleimide. The resulting iRGD-lipopeptides were used for fabrication of the iRGD-carrying αvβ3 integrin-targeted MBs (iRGD-MBs). The binding specificity of iRGD-MBs for endothelial cells was found to be significantly stronger than that of control MBs (p < 0.01) under in vitro static and dynamic conditions. The binding of iRGD-MBs on the endothelial cells was competed off by pre-incubation with the anti-αv or anti-β3 antibody (p < 0.01). Ultrasound images taken of mice bearing 4T1 breast tumors after intravenous injections of iRGD-MBs or control MBs revealed strong contrast enhancement within the tumors from iRGD-MBs but not from the control MBs; the mean acoustic signal intensity was 10.71 ± 2.75 intensity units for iRGD-MBs versus 1.13 ± 0.18 intensity units for the control MBs (p < 0.01). The presence of αvβ3 integrin was confirmed by immunofluorescence staining. These data indicate that iRGD-MBs can be used as an ultrasound imaging probe for the non-invasive molecular imaging of tumor angiogenesis, and may have further implications for ultrasound image-guided tumor targeting drug delivery.

Keywords: Microbubbles; Tumor angiogenesis; Ultrasound molecular imaging; iRGD; αvβ(3) integrin.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Breast Neoplasms / complications
Breast Neoplasms / diagnostic imaging
Breast Neoplasms / metabolism*
Cell Line, Tumor
Contrast Media / pharmacokinetics
Integrin alphaVbeta3 / chemistry
Integrin alphaVbeta3 / metabolism*
Lipopeptides / chemistry*
Mice
Molecular Imaging / methods*
Neovascularization, Pathologic / diagnostic imaging
Neovascularization, Pathologic / etiology
Neovascularization, Pathologic / metabolism*
Reproducibility of Results
Sensitivity and Specificity
Ultrasonography / methods*

Substances

Contrast Media
Integrin alphaVbeta3
Lipopeptides