Development of bovine serum albumin-modified hybrid nanoclusters for magnetofluorescence imaging and drug delivery

Abstract

In this study, bovine serum albumin (BSA) was used for simultaneously clustering and phase-transferring both oil-soluble AgInS₂–ZnS quantum dots (QDs) and MnFe₂O₄ magnetic nanoparticles (MNPs) under ultrasonication. The hybrid nanoclusters, BSA(QMs), thus produced were conjugated with folic acid (FA) and doxorubicin (DOX) to improve their target specificity and drug delivery to HeLa cancer cells. The resulting nanoclusters were characterized by employing different analytical techniques, and the results showed the nanocluster magnetofluorescence property derived from the clustering process. It was also found that the hybrid nanoclusters were biocompatible, non-toxic, and considerably stable over a wide range of pH values and at high ionic strengths. In addition, the in vitro confocal microscopy and MR relaxation studies revealed the yellow fluorescence and T₂ contrast-enhancing property of FA–BSA(QMs), as well as their cellular pathway to enter HeLa cells via folate receptor-mediated endocytosis. Furthermore, the cell viability data and flow cytometry results demonstrated the selective uptake of DOX–FA–BSA(QMs) by the HeLa cells, which significantly enhanced cell cytotoxicity. These results suggest that the proposed nanoclusters can be used as an effective and efficient strategy for magnetofluorescent probing and cancer drug delivery.