فهرست نشریات علمی دسترسی آزاد ایران

The effectiveness of light-mediated therapies depends on cancer cells’ optical response. We quantified the concentration-dependent optical behaviour of HCT116 cells exposed to TiO₂ nanoparticles in this study. To evaluate nanoparticle-induced photon propagation dynamics, diffuse reflectance and transmittance measurements in the visible range were taken and absorption coefficients and refractive index values computed. TiO₂ nanoparticle treatment caused a systematic change in optical properties. The absorbance coefficient and refractive index of treated cell suspensions were lower than untreated controls. The optical density of the cellular medium was modulated by nanoparticle concentration, as both the absorption coefficient and refractive index rose with nanoparticle concentration in the treated groups. These findings imply that dose-dependent nanoparticle incorporation alters photon attenuation and transmission routes, potentially affecting cell energy deposition. The measured data was used to theoretically derive quantum-optical parameters like photon energy, extinction coefficient, complex dielectric function, and optical conductivity to better describe light–matter interaction in the nanoparticle-treated cellular medium. Since TiO₂ has photocatalytic and photoactive capabilities, its optical modulation may impact light-based therapies that rely on controlled photon absorption and energy distribution for efficiency. The present study did not assess direct therapeutic endpoints, but the concentration-dependent optical and photonic trends show how engineered nanomaterials can tune cellular light–matter interactions, providing a photonic foundation for future nanoparticle-assisted cancer therapy research.