Aptamerized silica/gold nanocapsules for stimulated release of doxorubicin through remote two-photon excitation

Precision-based drug delivery via remote triggering is fast becoming an attractive therapeutic design and is highly useful in complicated clinical situations that may require accurate site-delivery of drug while reducing the risk of collateral damage to surrounding healthy tissue. Of the many strategies available to achieve these desirable effects, silica/gold nano-assemblies offers a practical means to achieving these aims. Herein, as a proof-of-concept, a silica nanocapsule passivated with a gold outer nanoshell had been fabricated to deliver Doxorubicin, and this nano-assembly can be remotely triggered via two-photon excitation (TPE), even under in vivo setting. A polyethylene glycol (PEG) layer as well as AS1411 DNA aptamer had also been grafted to the surface to improve homing specificity toward MDA-MB-231 breast cancer tissue. The assembly of silica/gold nanocapsules was characterized via TEM, FTIR, and UV-Vis to validate the the nanoconstruct. Upon TPE irradiation, a higher expression level of Annexin V and Caspase-3 was observed in both in vitro and in vivo animal models. A significant reduction in tumor size on mice model was noticed after 21 days, and these results had suggested a viable nano-sized design serving as remotely triggered drug release platform based on current well-established silica nanoparticulate methodologies.