Imaging of lung cancer cells with molecular beacons delivered by chitosan nanoparticles

Objective To investigate the effect of a method for imaging lung cancer cells using nanotechnology and molecular beacon (MB) that identifies miR-155 and is delivered by chitosan nanoparticles (CS). Methods The miR-155 MB modified by locked nucleic acids (LNAs) was designed and synthesized. The CS-MB complex was synthesized by self-assembly method and tested for its physicochemical properties including anti-DNase Ⅰfeatures, particle size, zeta potential and so on. The miR-155 MB was transfected with CS as vectors. The abilities of miR-155 MB to identify miR-155 and thus to image lung cancer cells were determined by confocal microscopy. Furthermore, the miR-155 expression levels were detected by qRT-PCR to validated the effect of miR-155 MB. The random sequence molecular beacon (RS MB) was set as a negative control. Results The CS-MB complex at the weight ratio of 7:1 was best suited for transfection due to its high encapsulation rate, resistance to the degradation by DNase Ⅰ, small particle size and positive charge. Relatively strong red fluorescence could be detected in the lung cancer cells after transfection of miR155 MB, while that could not be detected in the RS MB group (P