Quantitative study of concentration-dependent optical characteristics of nanoparticle-embedded tumor

Plasmonic photothermal therapy involves irradiation of a nanoparticle-embedded tumor, using near-infrared radiation, for its treatment. For a nanoparticle type, the absorption of incident radiation is governed by the nanoparticle dose (concentration of nanoparticles) and the type of tumor embedded with the nanoparticles. In this article, the optical characteristics (spectral absorption cross section, plasmonic wavelength and full-width half maxima) are computed, considering gold nanorod (GNR) doses of 0.02-1.0 mg/ml, for various tumor types i.e., colorectal, breast, brain and ameloblastoma. Also, the spatial distribution of nanoparticles within the tumor is accounted for. The results show that on increasing the GNR dose from 0.02 to 1.0 mg/ml, the peak absorption cross section increases by 26-28 times, whereas the plasmonic wavelength red-shifts by 8-13 nm and full-width half maxima increases by 68-71%. Depending on the spatial distribution of GNRs within the breast tumor, the optical absorption cross section increases by 45% and 94% for GNRs doses of 0.5 mg/ml and 1.0 mg/ml. These discussed results are of clinical significance for the prior estimation of nanoparticle dose-dependent optical characteristics for a tumor type. Based on these, suitable irradiation sources and parameters may be chosen for plasmonic photothermal therapy.

Automated summary

This study calculated the optical characteristics of gold nanorods in different doses for various tumor types, finding that increasing nanorod dose can enhance absorption cross section and result in a red-shift in plasmonic wavelength, which is important for selecting suitable irradiation sources and parameters for plasmonic photothermal therapy.