Self-assembled thermosensitive luminescent nanoparticles with peptide-Au conjugates for cellular imaging and drug delivery

A facile and efficient strategy has been developed to fabricate a multifunctional, theranostic anticancer drug delivery platform featuring active targeting, controlled drug release and fluorescence imaging for real-time control of delivery. To this end, thermosensitive poly(N-isopropyl acrylamide) (PNIPAM) nanospheres are decorated with peptide-Au cluster conjugates as a smart nanomedicine platform. A sophisticated trifunctional peptide is designed to release the anticancer drug doxorubicin (DOX), target cells and reduce Au³⁺ ions to form luminescent Au clusters. Importantly, the peptide-Au cluster moieties are attached to the PNIPAM nanospheres via amide bonds rather than noncovalent interactions, significantly improving their stability in biological medium and drug release efficiency. The in vitro experiments showed that DOX was released in an efficient and controlled manner under physiological conditions.