Multimodal theranostic nanoplatforms for nanomedicine applications

Targeted nanoparticle (NP)-based drug delivery has emerged with significant potential for nanomedicine [1]. Compared with other intensively studied noble metal nanomaterials, such as Au and Ag, Pd NPs exhibit distinctive features, including high photothermal conversion efficiency and chemical stability, remarkable photocatalytic activity, other than plasmonic properties, excellent biocompatibility, and high stability in the physiological environment. Moreover, Pd-based nanomaterials are highly versatile catalysts and ROS-inducing cancer treatment agents and can act as artificial antioxidant nanoenzymes (nanozymes) showing scavenging activity like that of natural enzymes, namely catalase, peroxidase, and SOD. In this work, we exploit the chemophotothermal potential of Pd NPs, developing a hybrid theranostic nanoplatform with cisplatin (Pd@CisPt), tested in prostate cancer cells (PC-3 line). Cytotoxicity tests and Raman microspectroscopy with PCA unveiled the antitumoral action of the developed nanomedicine, with a condition of protein misfolding/unfolding, directly or indirectly due to cisplatin and/or palladium treatment, and DNA damage especially enhanced upon the treatment with cisplatin-loaded nanoparticles. An increase in ROS generation was detected (MitoSOX assay), while scratch tests evidenced a tunable response in cell migration between the inhibitory effect by CisPt and the prompting effect by the metal NPs alone, thus pointing out the promising potential of the developed theranostic nanomedicine in tissue regeneration. The financial support by MUR under Grant PRIN (project code: 2017WBZFHL) and the University of Catania (PIACERI, 2020/2022 GRABIO_Linea di intervento 2) is acknowledged.