Target-responsive DNA aptamer-conjugated superparamagnetic Ag/CuS nanoparticles as near-infrared light-triggered theranostics and dual-modal imaging

Despite the benefits of chemotherapy, radiotherapy, and surgical resection in cancer treatment, the efficiency of these techniques is insufficient. The development of nanocarriers enabling combined diagnosis and therapy is progressive but still is limited. In this paper, we developed bandgap-modified Fe3O4@Ag@CuS nanoparticles conjugated with AS1411 DNA aptamer (aptaNPs) for photothermal therapy (PTT) and dual magnetic resonance (MR) and infrared (IR) imaging. It is shown that the developed nanoparticles induce localized surface plasmon resonance (LSPR) to promote the efficiency of photothermal therapy. In vitro and in vivo studies demonstrate that aptaNPs are highly specific against 4T1 cancer cells after intravenous administration over 8 h, owing to the target-responsive ability of aptamer. The results also determine improved uptake of aptaNPs in the target tissue as compared with the unconjugated-aptamer nanoparticles. A highly efficient light-to-heat conversion (34 %) with a mass extinction coefficient of 1.97 L cm-1 g-1 is also demonstrated. The developed hybrid nanoparticles bear the potential of combined monitoring (Fe3O4 in MRI), targeting (aptamers), and triggering (Ag@CuS in PTT); hence, they can be used for selective therapy of pathologies such as late-stage cancers and deep-seated cancerous tissues without causing damage to adjacent normal tissues.