Influence of different sized nanoparticles combined with ultrasound on the optical properties of in vitro normal and cancerous human lung tissue studied with OCT and diffuse reflectance spectra

Abstract

The present study is concerned with the in vitro study of different sized titanium dioxide (TiO2) nanoparticles’ (NPs) penetration and accumulation in human normal lung (NL) tissue and lung adenocarcinoma tumor (LAT) tissue by the methods of continuous optical coherence tomography (OCT) monitoring and diffuse reflectance (DR) spectra measurement, and their evaluating the effects of TiO2 NPs in two sizes (60 nm and 100 nm) and their combination with ultrasound (US) on the optical properties of human NL and LAT tissue. Spectral measurements indicate that TiO2 NPs penetrate and accumulate into the tissues and thus induce enhancement of DR. The averaged and normalized OCT signal intensity suggests that light penetration depth is significantly enlarged by ultrasound. The average attenuation coefficient of NL tissue changes from 5.10 ± 0.26 mm−1 to 3.12 ± 0.43 mm−1 and 2.15 ± 0.54 mm−1 at 120 min for 60 nm TiO2 NPs and 60 nm TiO2NPs/US treatment, respectively, and from 5.54 ± 0.46 mm−1 to 3.24 ± 0.73 mm−1 and 2.69 ± 0.34 mm−1 at 150 min for 100 nm TiO2 NPs and 100 nm TiO2NPs/US, respectively. The average attenuation coefficient of LAT tissue changes from 9.12 ± 0.54 mm−1 to 4.54 ± 0.39 mm−1 and 3.61 ± 0.38 mm−1 at 120 min for 60 nm TiO2 NPs and 60 nm TiO2NPs/US treatment, respectively, and from 9.79 ± 0.32 mm−1 to 5.12 ± 0.47 mm−1 and 4.89 ± 0.59 mm−1 at 150 min for 100 nm TiO2 NPs and 100 nm TiO2NPs/US, respectively. The results suggest that the optical properties of NL and LAT tissues are greatly influenced by TiO2 NPs and their combination with ultrasound.