Photothermal effect (PTE)

The photothermal effect is a physical phenomenon characterized by the conversion of absorbed light energy into thermal energy. In a biomedical context, this effect is the fundamental mechanism behind photothermal therapy (PTT), where exogenous photothermal agents (PTAs) are delivered to a specific site, such as a tumor, and then activated by external light irradiation (Liu et al., 2019, Theranostics). The resulting localized hyperthermia triggers cell death through mechanisms like protein denaturation, mitochondrial dysfunction, and cell membrane rupture. While highly effective for the precision ablation of localized lesions, the photothermal effect is a therapeutic modality or physical process rather than a biological target molecule like a receptor or enzyme. Its clinical application depends heavily on the development of biocompatible agents with high photothermal conversion efficiency and the ability to penetrate deep tissues using specific optical windows (National Institutes of Health, 2022; PubMed Central, PMC7405831).

Other names

Photothermal conversionLight-to-heat conversionPhotothermal hyperthermiaPTT mechanism

The photothermal effect involves the absorption of electromagnetic radiation (typically near-infrared light) by a photothermal agent, which promotes electrons to an excited state. This energy is subsequently released as kinetic energy through non-radiative vibrational relaxation, leading to a localized increase in temperature that induces thermal ablation and irreversible damage to target cells (Zhu et al., 2023, Journal of Nanobiotechnology; Vinegoni et al., 2021, Nature Communications).