Background: Fluorine-18-labeled glucose (FDG) has been used in clinical detection, staging, treatment and surveillance of tumors and other diseases. However, its radiological side effects have always troubled patients. Recently, near-infrared drug, a non-radioactive marker, has been gradually accepted by doctors and patients because of its non-toxicity, convenience in labeling and economic benefits. The following article explains the advantages and disadvantages of near-infrared imaging technology by taking the tumor imaging of a near-infrared labeled deoxyglucose analogue as an example.
Research methods: the authors of this article have found a glucose analogues: 2-NBDG, which can be transported to some tumor cells by glucose transporter (GLUT). Therefore, they have also begun to detect tumor markers in the preclinical small animal models after detecting the analogues and the NIR dye labeled (Cy5.5-2DG). Two dyes, Cy5.5-2DG and Cy5.5-NHS, are used in this paper. The former is a combination of D-glucosamine and Cy5.5-NHS.
The absorption spectrum of Cy5.5-2DG is 675 nm, and the generation spectrum is 695 nm (dashed line).
Partial results: Near infrared imaging of malignant glioma implanted subcutaneously
Two kinds of dyes were injected intravenously into nude mice tumor models. The results of multiple phases indicated that these two substances were higher than those of normal tissues in tumor sites (white arrow).
The same results were found in near infrared imaging of melanoma:
Discussion: In previous reports, 2-NBDG can enter living cells through the glucose transport system (GLUT) and aggregate in malignant cell lines such as breast cancer cell MCF-7 and hepatocellular carcinoma cell HepG2. The results of this study also show that 2-NBDG aggregates in the cytoplasm of U87MG cells, and that near-infrared labeled Cy5.5-2DG can enter many cancer cell lines. For example, C6, A75M, B16F0, MDA-MB-435 (results are not shown), and because the emission spectrum of 2-NBDG is 475nm, it is not suitable for animal imaging, limiting its clinical and pre clinical applications. Near infrared marking greatly improves its physical characteristics in optical imaging.
Summary: Near-infrared imaging is an effective means for the diagnosis of pre-clinical and clinical diseases, as well as for the real-time guidance of surgery. It has attracted the attention of many scientific researchers and medical personnel. Its non-invasive, non-radioactive and non-toxic characteristics make it have great potential and value in clinical and pre-clinical applications. The purpose of this paper is to develop optical probes suitable for near-infrared tumor-specific imaging, and the labeling ability of most near-infrared dyes also facilitates the research and development in this field.
With the development of technology, static imaging has been unable to meet the needs of scientific research and surgery. Near infrared real-time imaging has become a new favorite in optical imaging field. Fluobeam series produced by Fluoptics is the first hand-held open real-time imaging system with high sensitivity (can detect fluorescent signals of Pimo (10-12) or even Fermore (10-15). Compatible imaging of large animals and small animals is realized on the same instrument; the perfect combination of pre clinical experiments and real-time guidance of clinical operation is also achieved.