X-ray Nanothermometry of Nanoparticles in Tumour-Mimicking Tissues Under Photothermia.

Temperature plays a critical role in regulating body mechanisms and indicating inflammatory processes. Local temperature increments above 42°C have been shown to kill cancer cells in tumorous tissue, leading to the development of nanoparticle-mediated thermo-therapeutic strategies for fighting oncological diseases. Remarkably, these therapeutic effects can occur without macroscopic temperature rise, suggesting localized nanoparticle heating, minimizing side effects on healthy tissues. Nanothermometry has received considerable attention as a means of developing nanothermosensing approaches to monitor the temperature at the core of nanoparticle atoms inside cells. In this study, a label-free, direct, and universal nanoscale thermometry was proposed to monitor the thermal processes of nanoparticles under photoexcitation in the tumour environment. Gold-iron oxide nanohybrids were utilized as multifunctional photothermal agents internalized in a 3D tumour model of glioblastoma that mimics the in vivo scenario. The local temperature under near-infrared photo-excitation was monitored by X-ray absorption spectroscopy at the Au L 3 -edge (11900 eV) to obtain their temperature in cells, deepening our knowledge of nanothermal tumour treatments. This nanothermometric approach demonstrates its potential in detecting high nanothermal changes in tumor-mimicking tissues. It offers a notable advantage by enabling thermal sensing of any element, effectively transforming any material into a nanothermometer within biological environments. This article is protected by copyright. All rights reserved.