Background: Combination chemo-photothermal therapy appears to be one
of the next generations of cancer treatment. In this study hollow gold nanostars
(HGNSs) and gold nanocages (GNCs) were synthesized and stabilized with thermopH-
sensitive thiol-end capped ABC triblock copolymer poly(acrylic acid)-b-poly(N
isopropylacrylamide)-b-poly (e-caprolactone)-SH; PAA-b-PNIPAAm-b-PCL-SH (GNSs@
Pol). Doxorubicin (Dox) was conjugated to the GNSs@Pol nanostructures via ionic
interaction, covalent attachment and hydrogen bonding (GNSs@Dox-Pol). The physicochemical
characteristics of prepared GNSs@Pol and GNSs were assessed using dynamic
light scattering (DLS), transmission electron microscopy (TEM) and zeta potential
techniques. Cytocompatibility of the GNSs@Pol was studied by hemolysis assay and
MTT assay. The chemo-photothermal therapy (PTT) potential of GNSs@Dox-Pol was
compared on MCF7 cells using MTT assay, cell cycle, DAPI staining and Annexin-V
apoptosis assay techniques.
Results: Cell internalization results showed an almost complete uptake of GNSs@Pol
by MCF-7 cells in the first 3 h of treatment. The heat generation measurement results
showed that both of GNSs have a potential for light to heat conversion (ΔT = 23–27 ºC)
and HGNSs demonstrated better efficiency than GNCs after 10-min exposure to NIR
irradiation. Following chemo-photothermal treatment, the highest cell mortality (90%)
and apoptotic effects (97% apoptosis) were observed in HGNSs@Dox-Pol received laser
irradiation treatment group.
Conclusions: This work highlights the potential application of designed GNSs@Dox-
Pol in a combinational chemo-PTT to treat breast cancer cells.