Heat generation in biological tissues during photodynamic therapy combined with gold nanoparticles

One of the emerging strategies to overcome the actual drawbacks in Photodynamic Therapy is its combination with nanoparticles. Specifically, the administration of gold nanoparticles to the pathological tissue causes an increase in the optical radiation absorption that could lead to induce thermal damage in the target tissue. However, photodynamic therapy is based on photochemical interactions and therefore it is necessary to study possible thermal interactions that might occur in the target tissue due to the administration of nanoparticles. In this work we present a thermal model that tries to predict the effect of gold nanoparticles in the local heating for three different types of malignant skin tumors subjected to typical power densities applied in photodynamic therapy. The results obtained show a negligible increase in the local temperature that demonstrates the absence of thermal damage under the irradiation conditions commonly applied in photodynamic therapy clinical practice.