Preparation and characterization of GNRs stabled with the thiolated lemon polysaccharide and the applications for tumor photothermal therapy

Photothermal therapy is a novel strategy for cancer treatment, which can kill tumor cells by converting light energy into heat energy through irradiating photothermal conversion materials with laser. As a common photothermal agent, gold nanorods (GNRs) have characteristics of high conversion efficiency and long circulation time in vivo. However, improving stability and reducing toxicity of GNRs remain a significant challenge. In this research, a simple and novel strategy for the synthesis of modified GNRs was proposed. The polysaccharide CL90 was obtained from lemon, which was modified to afford thiolated lemon polysaccharide (SH-CL90). SH-CL90 was used to prepare stable GNRs and give the composite GNRs-SH-CL90, which was found to have good stability in PBS solution and possess high photothermal conversion effects and photothermal stability. The biological experiments revealed that GNRs-SH-CL90 inhibited tumor cell proliferation under near-infrared light irradiation and could induce apoptosis significantly. Furthermore, in vivo experiments supported that GNRs-SH-CL90 could inhibit the proliferation and migration of tumor cells. All the experiments demonstrated that GNRs-SH-CL90 might be promising in the field of cancer treatment.