In the present work, we demonstrate a potential use of gold nanorods as a contrast agent for selective photothermal
therapy of human acute leukemia cells (HL-60) using a near-infrared laser. Gold Nanorods (GNR) are synthesized
and conjugated to CD33, a 67 kDa glycoprotein found on the surface of myeloid cells that belongs to the
sialoadhesin family of proteins. After pegylation, or conjugation with CD33 antibody, GNR were non-toxic for
acute and chronic leukemia cells. We used a Quanta System q-switched titanium sapphire laser emitting at a center
wavelength of 755 nm. Each sample was illuminated with 1 laser shot at either high or low fluence. Both laser
modes were used in 3 independent cell probes. HL-60 cells were treated for 45 min with GNR conjugated with mAb
CD33, or with GNR-Pegylated particles. After laser application, the cells were resuspended and analyzed to cell
viability with Trypan blue exclusion assay. GNR-CD33 conjugates significantly increase the percentage of cell
death as compared with a control group after laser illumination: a 3 fold increase is observed.
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