Posted: Friday, April 14, 2023
Haihua Fan, PhD, of South China Normal University, Guangzhou, and colleagues investigated the use of gold nanobipyramids with good biocompatibility and infrared absorption peak in liver cancer cells (HepG2 cells) for photothermal ablation therapy. Their study, published in Scientific Reports, explored the photothermal effect and up-conversion fluorescence imaging effect of these nanoparticles on liver cancer cells, both theoretically and experimentally, by using higher photothermal conversion efficiency, shorter laser action time, smaller action range, and lower laser power.
“This result opens up a new way to develop photothermal ablation therapy with less side effects and more minimally invasive,” the investigators concluded.
Two types of gold nanobipyramids with absorption peaks in the first biologic window were synthesized, and two types of gold nanorods were also synthesized for comparison. The biocompatibility, cellular uptake, and two-photon fluorescence imaging of gold nanobipyramids and gold nanorods were investigated; results showed that gold nanobipyramids had better biocompatibility and higher fluorescence intensity than gold nanorods. The photothermal treatment effects of gold nanobipyramids and gold nanorods on liver cells were studied experimentally and theoretically.
The theoretical analysis showed that gold nanobipyramids had a stronger photothermal conversion effect than gold nanorods under femtosecond laser irradiation, raising temperatures by 516°C in 106 picoseconds. The experimental results showed that gold nanobipyramids and gold nanorods induced apoptosis rather than necrosis in cells, which reduced inflammation. The cells co-cultured with gold nanobipyramids were immediately induced to apoptosis after 20 seconds of pulsed laser irradiation with a power as low as 3 mW or 20 seconds of continuous laser irradiation with a power as low as 8.4 mW.
These findings provide new insights into the use of gold nanobipyramids in the development of photothermal ablation therapy for liver cancer and the promising application of gold nanoparticles in biomedicine, according to the investigators.
Disclosure: The study authors reported no conflicts of interest.