cadmium-free quantum dot nanocomposites for biophotonics and tumor targeting theranostics

Quantum dots (qds), as the zero-dimensional nanomaterials with the size ranging from 1 to ‎‎20 nm, are semiconductor nanocrystals. quantum dots have been engineered as a nanoscale ‎core-shell structure using types ii-vi, iv-vi, and iii-v semiconducting materials (cdse/zns, ‎cdse/cds, inas/cdse). in the recent years, qds have been considered attractive candidates ‎biological imaging because of their unique optical and physicochemical properties. a ‎synergistic combination of quantum dots with biophotonics provides remarkable ‎opportunities for consign many of the current challenges in disease diagnosis and therapy. ‎cadmium-containing including cdse, cdte, cds have devoted the highest research in ‎bioimaging and therapeutic applications among other qds, whereas the toxicity of cd ions ‎has been proven both in vitro and in vivo. we have developed a series of cd-free qds ‎including qds of group iii-v (inp, inas) for biological applications. surface functionalized ‎inp/zns qds by bioactive molecules such as folic acid and d-glucosamine and conjugated ‎with anti-cancer drugs have been engineered and their biological impacts were investigated. ‎in another approach, composites of inp/zns qds with stimuli- responsive hydrogels have ‎been prepared to achieve a new smart nanotheranostic. furthermore, for aptamer-mediated ‎targeted drug delivery, muc-1 aptamer modified cadmium-free qds have been prepared ‎and used for covalent conjugation of anticancer drugs including paclitaxel (ptx) to ‎targeting and eradication of breast cancer mcf-7 cells by inhibiting the mitochondrial ‎function. ‎in conclusion, hydrogel modified aptamer-conjugate qd nanocomposites are effective ‎nano-systems for targeting and molecular imaging and hold promise in early detection of ‎cancer. these results will have important impact in the engineering of clinically usable qds ‎for applications ranging from optical imaging to targeted drug and stem cell therapy ‎research.‎