The activated QDs were loaded onto an NAP-column (Life Technologies), and 500 L of colored eluate was collected approximately. tumor-to-background ratio and size of tumor image were highest within 6 hours of the injection and declined significantly at 9 hours after the injection, but there was still a clearly visible tumor image at 12 hours. The greatest amount of QD800-RGD was found in liver and spleen, followed by tumor and lung, and a poor fluorescence signal was seen in tibia. No detectable transmission of QD800-RGD was found in brain, heart, kidney, testis, belly, or intestine. Our study exhibited that using integrin v3 as target, it is possible to use intravenously injected QD800-RGD to generate high quality images of HNSCC, and the technique offers great potential in the diagnosis and personalized therapy for HNSCC. strong class=”kwd-title” Keywords: nanotechnology, near-infrared fluorescence, tumor angiogenic vessel, head and neck cancer, in vivo imaging Introduction Globally, there are approximately 650, 000 newly FGFR4-IN-1 diagnosed patients with head and neck malignancy annually, ranking it sixth among all cancers.1 Of them, 90% are head and neck squamous cell carcinoma (HNSCC).2 Surgery remains the major therapeutic option for HNSCC;3C5 however, the failure rate for complete removal of the cancer may be as high as 40%,6,7 due to the FGFR4-IN-1 fact that clinical doctors are currently not able to see the tumorCnormal boundary during the operation in a real-time way. Currently, boundary determination is based on magnetic resonance imaging and computed tomography images taken before the operation, as well as by personal experience and by feeling for changes in tissue texture round the tumor. Sometimes frozen pathological examinations of tumor boundary tissues suspected to contain residual malignancy tissue are performed to help guide the doctor. As such, the patients survival rate is usually greatly compromised. The development of real-time, in vivo tumor imaging systems is key to improving patient survival rate, since this would allow clinicians to see the boundaries of tumors during operations for the precise removal of malignancy tissues. The nanoparticles quantum dots (QDs) with near-infrared (NIR) emission spectra have been demonstrated to have high tissue penetration ability, and they have the properties of surface modifications to link to molecules capable of targeting cancers.8C18 In vivo optical imaging of NIR-QDs is particularly useful in personalized tumor treatment and diagnosis as compared with other currently Goat monoclonal antibody to Goat antiMouse IgG HRP. available technologies due to its ability to be imaged in real-time. QDs are semiconductor nanocrystals (diameter 1C10 nm) consisting of elements belonging to group IICIV or group IIICV.8C10 In comparison with organic fluorescent dyes and fluorescent proteins, they show many unique optical properties,9C11 such as narrow and tunable emission spectra, superior photostability, high quantum yields, and the capacity to simultaneously excite multiple fluorescence dyes. Furthermore, by FGFR4-IN-1 modifying the composition and size of QDs, it is possible to obtain QDs with a wide range of spectra from ultraviolet to NIR.12,13 QDs with emission wavelengths between 700C900 nm are capable of producing NIR fluorescence with strong tissue penetrating ability. With low absorbance by in vivo tissue, and with minimal interference from normal tissue autofluorescence, they are particularly suitable for bioimaging.8,9 Currently, most of the QDs utilized for in vivo imaging are targeted to the antigens or receptors that are highly expressed on cancer cell surfaces or specifically expressed in the tumor cells, where QDs that have been coupled with respective antibodies or ligands are able to bind specifically to these targets.14C18 For example, Shi et al14 and Gao et al15 coupled QDs with antibody against prostate-specific membrane antigen, generating a QD-prostate-specific membrane antigen probe to inject intravenously into nude mice bearing prostatic malignancy, and they successfully obtained fluorescence images of the tumor. Tada et al prepared an NIR fluorescence probe by linking QDs to monoclonal antibody against HER2 (human epidermal growth factor receptor-2). They were able to clearly image breast malignancy, where HER2 is usually highly expressed.16 In our early study, we coupled QDs with the epidermal growth factor receptor, which is highly expressed in the BcaCD885 (human buccal squamous cell.