Laser irradiation of human skin tissue after gold nanoparticles injection for thermal ablation processes – a combined experimental and numerical approach

In recent years, investigation of new or combined therapeutic modalities for cancer treatment lead to relevant scientific advances. Among these innovative therapeutic modalities photothermal therapy (PTT) attracts attention as an alternative or complementary possibility to current anti-cancer treatments as it allows for the selective ablation of cancer cells. In the present study, PTT is investigated by using gold nanoparticles (AuNPs) as photothermal transducers. AuNPs are injected into human skin and used for PTT-assisted tumor ablation. The effectiveness of the PTT is evaluated as a function of AuNPs morphology, dimensions and the wavelength of the laser source. Five different laser sources with wavelengths ranging from 465 to 980 nm are used. The experimental findings point out that 808 and 980 nm are the optimal laser wavelengths for the PTT of human skin. Especially gold nanorods stabilized by poly(ethylene glycol) layer are identified as effective photothermal transducers. The experimental results are fully corroborated by numerical calculations. The outcomes emphasize the potential and the relevance of synthetically tailoring AuNPs particularly in optimizing their optical properties and assessing the effects of AuNP aggregation for specific applications.