Low-Intensity Light-Responsive Anticancer Activity of Platinum(II) Complex Nanocolloids on 2D and 3D In Vitro Cancer Cell Model

This study aimed to evaluate the therapeutic e­cacy of low-intensity visible light responsive nanocolloids of a Pt-based drug using a 2D and three-dimensional (3D) in vitro cancer cell model. Biocompatible and biodegradable polymeric nanocolloids, obtained using the ultrasonication method coupled with Layer by Layer technology, were characterized in terms of size (100 ± 20 nm), physical stability, drug loading (78%), and photoactivation through spectroscopy studies. e in vitro biological effects were assessed in terms of e­cacy, apoptosis induction, and DNA-Pt adducts formation. Biological experiments were performed both in dark and under visible light irradiation conditions, exploiting the complex photochemical properties. e light-stimuli responsive nanoformulation gave a signicant enhancement in drug bioactivity. This allowed us to achieve satisfying results by using nanomolar drug concentration (50 nM), which was ineffective in darkness condition. Furthermore, our nanocolloids were validated in 3D in vitro spheroids using confocal microscopy and cytouorimetric assay to compare their behavior on culture in 2D monolayers. The obtained results conrmed that these nanocolloids are promising tools for delivering Pt-based drugs.