Folic acid-conjugated cationic Ag₂S quantum dots for optical imaging and selective doxorubicin delivery to HeLa cells

Aim: We aim to develop folic acid (FA)-conjugated cationic Ag2S near-infrared quantum dots (NIRQDs) for the delivery of doxorubicin (DOX) selectively to folate receptor (FR)-positive cancer cells to achieve enhanced drug efficacy and optical tracking in the NIR region. Materials & methods: Cationic Ag2S NIRQDs were decorated with FA using a PEG bridge and loaded with DOX. In vitro studies were performed on FR-positive human cervical carcinoma cells and FR-negative A549 cells. Results: Significantly higher uptake of DOX by human cervical carcinoma cells cells and a greater therapeutic effect along with a strong intracellular optical signal were obtained with DOX-loaded FA-conjugated Ag2S NIRQDs. Conclusion: These Ag2S NIRQDs are promising theranostic nanoparticles for receptor-mediated delivery of DOX with enhanced drug efficacy combined with optical imaging.