Pegylated gold nanoparticles induce apoptosis in human chronic myeloid leukemia cells

Gold nanoparticles (AuNPs) have several potential biological applications as well as excellent biocompatibility. AuNPs with surface modification using polyethylene glycol (PEG-AuNPs) can facilitate easy conjugation with various biological molecules of interest. To examine the anticancer bioactivity of PEG-AuNPs, we investigated their effect on human chronic myeloid leukemia K562 cells. The results indicated that PEG-AuNPs markedly inhibited the viability and impaired the cell membrane integrity of K562 cells. The particles caused morphological changes typical of cell death, and a marked increase in the sub-G1 population in DNA histogram, indicating apoptosis. In addition, PEG-AuNPs reduced the mitochondrial transmembrane potential, a hallmark of the involvement of intrinsic apoptotic pathway in K562 cells. Observation of ultrastructure under a transmission electron microscope revealed that the internalized PEG-AuNPs were distributed into cytoplasmic vacuoles and damaged mitochondria, and subsequently accumulated in areas surrounding the nuclear membrane. In conclusion, PEG-AuNPs may have the potential to inhibit growth and induce apoptosis in human chronic myeloid leukemia cells.