Synthesis of a Single-Stranded DNA Aptamer Modified Near-infrared, Water-Soluble Fluorophore for Lung Cancer Cell Imaging

摘要

In recent years, aza-boron dipyrromethene (aza-BODIPY) derivatives have attracted considerable attention as fluorescent imaging agents. In this work, two polyethylene glycol functionalized water soluble aza-BODIPY derivatives (a mono cycloaddition product 1PEG-BOD and a double cycloaddition product 2PEG-BOD) were synthesized through a cycloaddition click reaction between aza-BODIPY and N-3-PEG(2000)-COOH. The absorption and fluorescence profiles of these two compounds were in near-infrared region. The fluorescence quantum yield of 2PEG-BOD was 20 times higher than 1PEG-BOD in water. The attachment of an A549 lung cancer cell targeting aptamer with 2PEG-BOD afforded APT-PEG-BOD. The average fluorescence intensity of APT-PEG-BOD (5 mu mol/L) in A549 lung cancer cells calculated from confocal microscopy images was 25-33 times stronger than that in other cell lines, such as MDA-MB-231, HT1080 and LO2. These results indicated that APT-PEG-BOD shows high affinity to A549 lung cancer cells.