Silver Atomic Quantum Clusters of Three Atoms for Cancer Therapy: Targeting Chromatin Compaction to Increase the Therapeutic Index of Chemotherapy

Abstract

Nanomaterials with very low atomicity deserve consideration as potential pharmacological agents owing to their very small size and to their properties that can be precisely tuned with minor modifications to their size. Here, it is shown that silver clusters of three atoms (Ag -AQCs)-developed by an ad hoc method-augment chromatin accessibility. This effect only occurs during DNA replication. Coadministration of Ag -AQCs increases the cytotoxic effect of DNA-acting drugs on human lung carcinoma cells. In mice with orthotopic lung tumors, the coadministration of Ag -AQCs increases the amount of cisplatin (CDDP) bound to the tumor DNA by fivefold without modifying CDDP levels in normal tissues. As a result, CDDP coadministered with Ag -AQCs more strongly reduces the tumor burden. Evidence of the significance of targeting chromatin compaction to increase the therapeutic index of chemotherapy is now provided.

Increasing the optical response of TiO2 and extending it into the visible region through surface activation with highly stable Cu5 clusters

“…For example, due to their small size, atomic clusters do not retain their metallicity and do not show plasmonic behavior, which is very characteristic of Au, Ag and Cu nanoparticles in the visible region 13. Instead, the presence of a molecule-like HOMO–LUMO gap has a strong impact on their chemical and physical properties with potential applications including luminescence,14 sensing,15 therapeutics,16 energy conversion,17 and catalysis 18. Although some results were reported before for the use of metal clusters as photosensitizers of solar cells19 and to extend the photoactivity of TiO 2 ,20 the increase in activity was only moderate.…”

“…This can be achieved by kinetic control using electrochemical methods. Such techniques open the possibility for numerous applications ranging from cancer therapeutic drugs16 to efficient hydrogen photoproduction 22…”

Exploring the Catalytic Properties of Unsupported and TiO2-Supported Cu5 Clusters: CO2 Decomposition to CO and CO2 Photoactivation

“…As opposed to metal nanoparticles in the visible region, 1 these “atomic” or subnanometer-sized clusters do not sustain their metallicity and do not show plasmonic behavior. Instead, the presence of a molecule-like HOMO–LUMO gap impacts their chemical and physical properties, making them innovative materials for applications including luminescence, 2 sensing, 3 therapeutics, 4 energy conversion, 5 catalysis, 6 and electrochemical applications. 7,8 In particular, Cu 5 clusters have been shown to be less susceptible to oxidation than larger systems like Cu 8 or Cu 20 and have therefore been proposed as promising catalysts.…”

Synthetic strategies of supported atomic clusters for heterogeneous catalysis

“…Naked Ag 2 and Ag 3 clusters can be prepared using a very low concentration of Ag ions in solution 108 . Combing with DNAacting drugs, the Ag 3 clusters that strongly intercalate with DNA play an essential role in improving cytotoxicity to human lung carcinoma cells 109 . Using a modified electrochemical method, Au 3 , Au 5-7 , and Au 7-10 clusters were synthesized and supported on functionalized carbon nanotubes by a wet impregnation procedure.…”