Three-prong photothermal therapy eliminates tumours in mice

Good news! Cancer is history!

"Photothermal therapy – a cancer treatment based on laser irradiation of injected gold nanorods – provides high tumour targeting accuracy with low toxicity. Now researchers in China have developed a new nanoplatform that completely eliminates solid liver cancer tumours in mice following a single five-minute light dose and without toxic side effects.

The treatment works by injecting gold nanorods directly into a tumour and then irritating them with near-infrared (NIR) laser light. This causes the nanorods to heat up and kill surrounding cancer cells. Photothermal therapy alone, however, can fail due to incomplete tumour ablation, particularly for larger lesions. This is mainly due to the limited penetration depth of light into tissue and the nanorods not fully permeating throughout the tumour.

To address these issues, the researchers deposited clusters of palladium (Pd) on the ends of gold (Au) nanorods to create heterogeneous Pd-Au nanorods. To improve biocompatibility, they modified the nanorod surfaces with bovine serum albumin (BSA). The introduction of Pd nanoclusters improves the photothermal therapy in three unique ways[:]

[1)] the BSA-Pd-Au nanorods absorb light at longer wavelengths than standard gold nanorods, extending the maximum absorption wavelength from 950 nm to 1050 nm. In this NIR-II region, light penetrates deeper into tissue and can be used at higher maximum skin exposures.

[2)], the nanorods can be used to activate Pro-5-Fu, a prodrug of the chemotherapy drug 5-fluorouracil (5-Fu). By injecting Pro-5-Fu intraperitoneally, then synthesizing 5-Fu in situ at the site of the BSA-Pd-Au nanorods, the potential for damaging healthy cells is minimized.
[3)], the nanorods convert hydrogen peroxide into harmful reactive oxygen species. This so-called chemodynamic therapy (CDT) helps eliminate any residual tumour cells. ..."

Three-prong photothermal therapy eliminates tumours in mice – Physics World