Wrapping of Drug Assembly with Silica Layer and Confinement through Reversible Linkage with Copper(II) for Glutathione-Responsive Nanocapsule

Colloidal nano-assembly containing doxorubicin (DOX) is prepared for the first time by co-precipitation with gluconate. The spherical assembly is wrapped with a porous silica layer via sol-gel process, and confined in the formed cage by treatment with copper(II) ions (Cu2+). The reversible linking of DOX with Cu2+ is allowed to suppress the leakage of DOX, but the quick release is turned on in response to glutathione (GSH). The synthesized stimulus-responsive nanocapsules are characterized, and examined in the release test with/without GSH and applied to living HeLa cells. Spherical molecular assembly containig doxorubicin (DOX) is prepared by co-precipitatinon of doxorubicin hydrochloride and sodium gluconate (NaGlc), and then wrapped with porous silica layer via sol-gel process. The permeation of Cu2+ is allowed to suppress the leaking of the contents due to the blocking of the microchannels in the surronding layer, but release DOX immediately in response to glutathione (GSH).