Quantum dot-antisense oligonucleotide conjugates for multifunctional gene transfection, mRNA regulation, and tracking of biological processes

It was demonstrated that oligonucleotides , independent of their base sequence and length, could effectively induce the cellular uptake of mercapto acid-capped CdTe QDs after the oligonucleotides were covalently attached on the surface of the QDs. Following these experimental observations, a conjugate composed of covalently linked anti-survivin antisense oligonucleotides (ASON) and CdTe QDs was designed and synthesized. Then, the survivin mRNA down-regulation and the apoptosis of HeLa cells induced by ASON were studied. Systematic experimental results revealed that CdTe-ASON could effectively induce the apoptosis of HeLa cells, while CdTe QDs offered the possibility to visualize the specific intracellular localization of the CdTe-ASON probes strongly associated with their biological functions.