In-vivo imaging of oral squamous cell carcinoma by EGFR monoclonal antibody conjugated near-infrared quantum dots in mice

OBJECTIVES: The purpose of this study was to investigate in-vivo visible imaging of oral squamous cell carcinoma (OSCC) by targeting epidermal growth factor receptor (EGFR) with near-infrared quantum dots. MATERIALS AND METHODS: Quantum dots with an emission wavelength of 800 nm (QD800) were conjugated to monoclonal antibodies against EGFR, resulting in the probe designated as QD800-EGFR Ab. OSCC cell line (BcaCD885) expressing high levels of EGFR was transplanted subcutaneously into nude mice cheeks to develop an OSCC animal model. QD800-EGFR Ab containing 100 pmol equivalent of QD800 was intravenously injected into the animal model, and in-situ and in-vivo imaging of cheek squamous cell carcinoma was analyzed at 10 different time points. RESULTS AND CONCLUSION: In-vivo imaging and immunohistochemical examination of the tumors showed that intravenously injected QD800-EGFR Ab probe could bind EGFR expressed on BcaCD885 cells. Fluorescence signals of BcaCD885 cells labeled with QD800-EGFR Ab probe could be clearly detected, and these fluorescence signals lasted for 24 hours. The most complete tumor images with maximal signal-to-noise ratio were observed from 15 minutes to 6 hours after injection of the probe. To the best of the authors’ knowledge, this is the first study that has obtained clear in-situ and in-vivo imaging of head and neck cancer by using QD800-EGFR Ab probe. The authors conclude that the combination of near-infrared quantum dots that are highly penetrating for tissues with EGFR monoclonal antibody has promising prospects in in-vivo imaging of OSCC and development of personalized surgical therapies.