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Plasmonic Pd nanosheets have been emerging as promising materials for applying in near-infrared (NIR) photothermal therapy (PTT) of cancer. However, animal in mice studies indicated that the original synthesized poly(vinylpyrrolidone) (PVP)-protected small Pd nanosheets (Pd-PVP) and some further surface-modified small Pd nanosheets such as Pd-PEG(SH) easily accumulated in reticuloendothelial system (RES) organs (liver, spleen, etc.) and were difficult to be cleared from these organs quickly. In the work, we surprisingly found that glutathione (GSH) could promote the clearance of surface-modified small Pd nanosheets (e.g. Pd-PVP, Pd-PEG(SH) and Pd-GSH) from the RES organs efficiently. The effects of GSH on the biodistribution and clearance of different surface-modified Pd nanosheets were investigated. Our results indicated that these surface-modified Pd nanosheets with or without GSH added caused no morbidity at target primary organs, and GSH can promote the clearance of different surface-modified Pd nanosheets in the order of Pd-PVP≈Pd-PEG(SH)>Pd-GSH. This study suggests that glutathione could be an attractive reagent for promoting nanomaterials eliminated from the reticuloendothelial systems (RES).

In this work, we prepared chlorin e6 (Ce6)-functionalized Pd nanosheets (Pd-PEI-Ce6) for the photodynamic and photothermal combined therapy that use a single laser. To fabricate the Pd-PEI-Ce6 nanocomposite, photosensitizer Ce6 were chemically conjugated to polyethylenimine (PEI) and the formed Ce6-PEI conjugates were then anchored onto Pd nanosheets by electrostatic and coordination interaction. The prepared Pd-PEI-Ce6 nanocomposite were about 4.5 nm in size, exhibited broad, and strong absorption from 450 to 800 nm, good singlet oxygen generation capacity and photothermal conversion efficiency, and excellent biocompability. Significantly greater cell killing was observed when HeLa cells incubated with Pd-PEI-Ce6 were irradiated with the 660 nm laser, attributable to both Pd nanosheets-mediated photothermal ablation and the photodynamic destruction effect of photosensitizer Ce6. The double phototherapy effect was also confirmed in vivo. It was found that the Pd-PEI-Ce6 treated tumor-bearing mice displayed the enhanced therapeutic efficiency compared to that of Pd-PEI, or Ce6-treated mice. Our work highlights the promise of using Pd nanosheets for potential multimode cancer therapies.

Hollow mesoporous zirconia nanocapsules (hm‐ZrO2) with a hollow core/porous shell structure are demonstrated as effective vehicles for anti‐cancer drug delivery. While the highly porous feature of the shell allows the drug, doxorubicin(DOX), to easily pass through between the inner void space and surrounding environment of the particles, the void space in the core endows the nanocapsules with high drug loading capacity. The larger the inner hollow diameter, the higher their DOX loading capacity. A loading of 102% related to the weight of hm‐ZrO2is achieved by the nanocapsules with an inner diameter of 385 nm. Due to their pH‐dependent charge nature, hm‐ZrO2loaded DOX exhibit pH‐dependent drug releasing kinetics. A lower pH offers a faster DOX release rate from hm‐ZrO2. Such a property makes the loaded DOX easily release from the nanocapsules when up‐taken by living cells. Although the flow cytometry reveals more uptake of hm‐ZrO2particles by normal cells, hm‐ZrO2loaded DOX release more drugs in cancer cells than in normal cells, leading to more cytotoxicity toward tumor cells and less cytotoxicity to healthy cells than free DOX.

The increase of antibiotic resistance in bacteria has become a major concern for successful diagnosis and treatment of infectious diseases. Over the past few decades, significant progress has been achieved on the development of nanotechnology‐based medicines for combating multidrug resistance in microorganisms. Among this, silver nanoparticles (AgNPs) hold great promise in addressing this challenge due to their broad‐spectrum and robust antimicrobial properties. This review illustrates the antibacterial mechanisms of silver nanoparticles and further elucidates how different structural factors including surface chemistry, size, and shape, impact their antibacterial activities, which are expected to promote the future development of more potent silver nanoparticle‐based antibacterial agents. Silver nanoparticles (AgNPs)hold great promise to address the challenges in multidrug resistance in bacteria. This review briefly summarizes the current understanding of antibacterial mechanisms of AgNPs and how surface chemistry, size, and shape, impact their potencies, which are expected to help further development of AgNP‐based antibacterial agents.