Ultra‐Small High‐Entropy Alloy Nanoparticles: Efficient Nanozyme for Enhancing Tumor Photothermal Therapy

Abstract

High‐entropy alloys nanoparticles (HEANPs) are receiving extensive attention due to their broad compositional tunability and unlimited potential in bioapplication. However, developing new methods to prepare ultra‐small high‐entropy alloy nanoparticles (US‐HEANPs) faces severe challenges owing to their intrinsic thermodynamic instability. Furthermore, there are few reports on studying the effect of HEANPs in tumor therapy. Herein, the fabricated PtPdRuRhIr US‐HEANPs act as bifunctional nanoplatforms for the highly efficient treatment of tumors. The US‐HEANPs are engineered by the universal metal‐ligand cross‐linking strategy. This simple and scalable strategy is based on the aldol condensation of organometallics to form the target US‐HEANPs. The synthesized US‐HEANPs exhibit excellent peroxidase‐like (POD‐like) activity and can catalyze the endogenous hydrogen peroxide to produce highly toxic hydroxyl radicals. Furthermore, the US‐HEANPs possess a high photothermal conversion effect for converting 808 nm near‐infrared light into heat energy. In vivo and in vitro experiments demonstrated that under the synergistic effect of POD‐like activity and photothermal action, the US‐HEANPs can effectively ablate cancer cells and treat tumors. It is believed that this work not only provides a new perspective for the fabrication of HEANPs, but also opens the high‐entropy nanozymes research direction and their biomedical application.

Transition-Metal-Based Nanozymes: Synthesis, Mechanisms of Therapeutic Action, and Applications in Cancer Treatment

“…PTT is considered a noninvasive therapeutic modality that utilizes photothermal agents to convert light energy into hyperthermia, thereby inducing apoptosis and necrosis in tumor cells. , Importantly, the localized elevation of temperature resulting from PTT significantly enhances the catalytic activity of nanozymes, thereby achieving augmented catalytic therapy. , For example, Yang et al developed Ti 3 C 2 T x -Pt-PEG nanocomposites, in which Pt was used as a POD-like nanozyme and Ti 3 C 2 T x served as a photothermal agent for photothermal enhanced catalytic therapy (Figure A) . The photothermal-conversion efficiency of Ti 3 C 2 T x -Pt-PEG nanocomposites was calculated to be 31.78%, demonstrating the superior photothermal performance of Ti 3 C 2 T x -Pt-PEG.…”

Layered Double Hydroxide-Based PdCux@LDH Alloy Nanozyme for a Singlet Oxygen-Boosted Sonodynamic Therapy

“…As reported, the catalytic efficiency can be clearly tailored by modulating the compositions, sizes, and morphologies of noble metal-based nanozymes, so it is expected to achieve efficient enzyme-like activity by finely regulating the structures and morphologies of nanozymes. − Notably, it has been shown that palladium nanocrystals display facet-dependent CAT-like and OXD-like properties. , Thus, a Pd-based nanozyme with concurrently exposed Pd(111) and Pd(100) facets would be extremely efficient for synergetic CAT- and OXD-like dual therapy to produce highly toxic 1 O 2 via cascade catalysis. Moreover, it is found that compared with other precious metals, Pd has the highest decomposition energy barrier to activate H 2 O 2 for producing •OH, which is conducive to the formation of more 1 O 2 . However, the limited electron transport and intrinsic electronic structure of monometallic materials restrict their catalytic activity .…”

“…Moreover, it is found that compared with other precious metals, Pd has the highest decomposition energy barrier to activate H 2 O 2 for producing •OH, which is conducive to the formation of more 1 O 2 . 14 However, the limited electron transport and intrinsic electronic structure of monometallic materials restrict their catalytic activity. 15 Consequently, the growing evidence suggests that multimetal alloy nanozymes should be studied.…”

Synthesis of metallic high-entropy alloy nanoparticles

“…In the past five years, HEA research has predominantly focused on synthesizing HEA nanoparticles and exploring their applications in energy-related fields, including catalysis, 6–15 electrochemical energy storage, 11,16–20 and light harvesting and conversion. 21–26 The emergence of HEA nanomaterials and their promising properties have attracted extensive attention and resulted in some review articles primarily focused on catalysis. 8,9,11–14 Although the synthesis of HEA nanomaterials is crucial for exploring their unique properties, a focused and insightful overview of synthetic strategies is still rare in the literature.…”