Biodegradable and self-fluorescent ditelluride-bridged mesoporous organosilica/polyethylene glycol-curcumin nanocomposite for dual-responsive drug delivery and enhanced therapy efficiency

Mesoporous organosilica as drug delivery carriers capable of achieving improved cargo release, enhanced biodegradation, and direct imaging with prolonged circulation time and tracking cargo distribution is highly in demand for biomedical applications. Herein, we report a ditelluride-bridged mesoporous organosilica nanoparticle (DTeMSN)/polyethylene glycol-curcumin (PEG-CCM) nanocomposite through coassembly with oxidative/redox and self-fluorescent response. Tellurium is introduced into the silica framework for the first time as a drug delivery vehicle. In this case, the DTeMSNs as an inner core enable disassembly under oxidative and redox conditions via the cleavage of ditelluride bond, facilitating the drug release of doxorubicin (DOX) in a matrix degradation controlled manner. Through the systematical comparison of diselenide-bridged MSNs and DTeMSNs, DTeMSNs exhibit remarkable advantages in loading capacity, drug release, and degradation behavior, thereby significantly affecting the cytotoxicity and antitumor efficacy. The self-fluorescent response of PEG-CCM shell coated on the surface of DTeMSNs can real-timely track the cellular uptake, DOX release, and biodistribution owing to the intrinsic and stable fluorescence of CCM. Moreover, PEG-CCM could prolong circulation time, provide preferable drug accumulation in tumors, and increase antitumor efficacy of DOX-loaded DTeMSNs. Our findings are likely to enrich the family of organosilica that served as fluorescence-guided drug delivery carriers.