PEGylated thermosensitive lipid-coated hollow gold nanoshells for effective combinational chemo-photothermal therapy of pancreatic cancer.

Pancreatic cancer has extremely poor prognosis with an 85% mortality rate that results from aggressive and asymptomatic growth, high metastatic potential, and rapid development of resistance to already ineffective chemotherapy. In this study, plasmonic hollow gold nanoshells (GNS) coated with PEGylated thermosensitive lipids were prepared as an efficient platform to ratiometrically co-deliver two drugs, bortezomib and gemcitabine (GNS-L/GB), for combinational chemotherapy and photothermal therapy of pancreatic cancer. Bortezomib was loaded within the lipid bilayers, while gemcitabine was loaded into the hydrophilic interior of the porous GNS via an ammonium sulfate-driven pH gradient method. Physicochemical characterizations and biological studies of GNS-L/GB were performed, with the latter using cytotoxicity assays, cellular uptake and apoptosis assays, live/dead assays, and western blot analysis of pancreatic cancer cell lines (MIA PaCa-2 and PANC-1). The nanoshells showed remotely controllable drug release when exposed to near-infrared laser for site-specific delivery. GNS-L/GB showed synergistic cytotoxicity and improved internalization by cancer cells. High-powered near-infrared continuous wave laser (λ=808nm) effectively killed cancer cells via the photothermal effect of GNS-L/GB, irrespective of cell type in a power density-, time-, and GNS dose-dependent manner. These results suggest that this method can provide a novel approach to achieve synergistic combinational chemotherapy and photothermal therapy, even with resistant pancreatic cancer.