Molecularly imprinted gelatin nanoparticles for DNA delivery and in-situ fluorescence imaging of telomerase activity.

DNA-loaded molecularly imprinted gelatin nanoparticles (GDMI-NPs) were prepared to deliver the Cy3- and Cy5-labelled DNA probe to a tumor region. This allows the activity of telomerase can be detected over 3-400 cells with a low detection limit (3 cells). Fluorescence images were acquired at an excitation wavelength of 535 nm and the emission from the green channel (550-580 nm; label Cy3) and the red channel (650-680 nm; label Cy5). HeLa cells and HepG2 cells were both used to test the performance of GDMI-NPs. Experimental results confirmed the GDMI-NPs has hardly retained in liver and spleen tissue, and its circulated time was longer than that of non-imprinted nanoparticles in blood. The ability of GDMI-NPs to resist immuno stress and anti-macrophage phagocytosis shows great potential for cancer diagnosis and as a drug carrier. Graphical abstract Highly DNA-loaded molecularly imprinted gelatin nanoparticles (GDMI-NPs) were prepared to deliver the Cy3-labelled DNA probe to a cancer region, and realization of telomerase in situ fluorescence imaging at the tumor site.