Dual-aptamer-based delivery vehicle of doxorubicin to both PSMA (+) and PSMA (−) prostate cancers

We have designed a dual-aptamer complex specific to both prostate-specific membrane antigens (PSMA) (+) and (−) prostate cancer cells. In the complex, an A10 RNA aptamer targeting PSMA (+) cells and a DUP-1 peptide aptamer specific to PSMA (−) cells were conjugated through streptavidin. Doxorubicin-loaded onto the stem region of the A10 aptamer was delivered not only to PSMA (+) cells but to PSMA (−) cells, and eventually induced apoptosis in both types of prostate cancer cells. Cell death was monitored by measuring guanine concentration in cells using differential pulse voltammetry (DPV), a simple and rapid electrochemical method, and was further confirmed by directly observing cell morphologies cultured on the transparent indium tin oxide (ITO) glass electrode and checking their viabilities using a trypan blue assay. To investigate the in vivo application of the dual-aptamer system, both A10 and DUP-1 aptamers were immobilized on the surface of thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION). Selective cell uptakes and effective drug delivery action of these probes were verified by Prussian blue staining and trypan blue staining, respectively.