Palladium-based nanomaterials for cancer imaging and therapy

Abstract

In recent decade, palladium-based (Pd-based) nanomaterials have shown significant potential for biomedical applications because of their unique optical properties, excellent biocompatibility and high stability in physiological environment. Compared with other intensively studied noble nanomaterials, such as gold (Au) and silver (Ag) nanomaterials, research on Pd-based nanomaterials started late, but the distinctive features, such as high photothermal conversion efficiency and high photothermal stability, have made them getting great attention in the field of nanomedicine. The goal of this review is to provide a comprehensive and critical perspective on the recent progress of Pd-based nanomaterials as imaging contrast agents and therapeutic agents. The imaging section focuses on applications in photoacoustic (PA) imaging, single-photon emission computed tomography (SPECT) imaging, computed tomography (CT) imaging and magnetic resonance (MR) imaging. For treatment of cancer, single photothermal therapy (PTT) and PTT combined with other therapeutic modalities will be discussed. Finally, the safety concerns, forthcoming challenges and perspective of Pd-based nanomaterials on biomedical applications will be presented.

Atomically Precise Gold Nanoclusters: Towards an Optimal Biocompatible System from a Theoretical–Experimental Strategy

“…[ 49 ] Thus, it is time to expand the investigations of AuNCs‐based agents in this field, but now including comparisons with more promising and emerging nanostructures, such as palladium (Pd)‐based nanomaterials. [ 50 ] Interestingly, Pd nanosheets (16 nm) were reported to have high photothermal efficiency and showed superior stability, measured against AuNPs (nanorods). [ 51 ] However, these findings might substantively differ when the point of comparison is AuNCs instead, due to their exceptional features described above, which can only be obtained when the size of NPs is reduced to the NC range.…”

Nano-enabled theranostics for cancer

“…Au nanoparticles can be tuned to absorb NIR light which can be converted into heat to kill the cancer cells via hyperthermia. 99 Carbon nanomaterials such as carbon nanotubes, graphene oxide and carbon nanodots are also attractive for their tunable photoluminescent properties and have been extensively used for PDT, photothermal therapy, 100 photoacoustic imaging, 101 and optical imaging. 102…”

Low-Temperature Photothermal Therapy: Strategies and Applications

“…In the past decades, researchers have found a large number of nanomaterials possessing photothermal conversion capacity, which can be categorized into two groups—inorganic PTAs and organic PTAs. The inorganic PTAs include metal or metal-containing nanomaterials including gold nanostructures [ 11 , 12 ], palladium-based nanostructures [ 13 – 15 ], iron or copper-containing nanoparticles (NPs) [ 16 – 19 ], transition metal chalcogenides [ 20 ], and quantum dots [ 21 , 22 ]. On the other hand, organic materials [ 23 ] including near-infrared (NIR) dyes represented by cyanine dyes [ 24 – 32 ], conjugated polymers (e.g., polydopamine (PDA), polyaniline, polypyrrole, and poly(3,4-ethylenedioxythiophene)) [ 33 – 36 ], and some carbon-based nanomaterials (most of them are organic materials; as represented by graphite-related nanostructures) [ 37 – 41 ] have also been utilized for PTT.…”