Laser-Assisted Permeation of Titanium Dioxide Nanoparticles in Ex Vivo Human Endometrium Tissues Monitored by OCT and Diffuse Reflectance Spectra

This study aims to monitor and assess the penetration and accumulation of titanium dioxide nanoparticles ( $TiO_{2}$ NPs) (25 nm and 60 nm) and the penetration of the $TiO_{2}$ NPs assisted by diode laser radiation (LR) in human normal endometrium (NE) and uterine leiomyoma (UL) tissues. In the 210 min ex vivo experiments, optical coherence tomography (OCT) and diffuse reflectance (DR) spectral measurement were used to study the changes in optical properties of tissues after $TiO_{2}$ NPs suspension administering. The results show that $TiO_{2}$ NPs make the OCT signal intensities and DR spectra of both NE and UL tissues increase with time, and larger NPs produce greater signal enhancement. In addition, there are significant differences between NE and UL tissues in terms of the values of attenuation coefficients. The experiment results indicate that the same size of the NPs penetrate faster in UL tissues than that in NE tissues, and 25 nm $TiO_{2}$ NPs allow larger penetration depth than 60 nm $TiO_{2}$ NPs in tissues. LR can remarkably increase the penetration of $TiO_{2}$ NPs in two types of tissues, especially in UL tissues. Analysis of attenuation coefficients and reflectance intensity reveals that the accumulation of the $TiO_{2}$ NPs in NE and UL tissues has great influence on the tissue optical properties.