NIR-II-responsive nickel-based therapeutics provide new solution for synergistic oncotherapy

A polyethylene glycol-modified urchin-like nickel nanoclusters (PUNNC) with an applied 9T magnetic field, when used for photothermal enhanced chemodynamic synergistic therapy under near-infrared (NIR)-II radiation, can efficiently kill tumor cells in vitro and inhibit tumor tissue growth in vivo, according to a paper published on Theranostics recently.

The solvothermal synthesis of novel 9T-PUNNC was reported by a collaborative research team led by Professor Wang Hui from High Magnetic Field Laboratory, Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Sciences (CAS).

Chemodynamic therapy (CDT) based on Fenton or Fenton-like reactions to in situ generate hydroxyl radicals (·OH) has received extensive attention in these years due to low side effects and non-invasive treatment modality. Among the various non-metal-based or metal-based nanomaterials that have been reported as Fenton agents for CDT and photothermal agents for PTT, it is difficult to make greater progress in the combined therapy due to the inherent instability, low catalytic efficiency, and poor photothermal conversion efficiency of the materials. Therefore, it is necessary to design a new therapeutic agent for combined therapy.

In this research, researchers used a one-step solvothermal method to synthesize PUNNC modified with PEG to improve stability and biocompatibility under an applied magnetic field.

Thanks to the increased magnetic field strength, which helped to increase the length of the needle-like protrusions on the surface and reduce the crystallinity of the nickel clusters, 9T-PUNNC can effectively absorb NIR-II and convert it into local heat to achieve the effect of PTT, while the decreased crystallinity and increased local temperature accelerate the acidification process of PUNNC.

It promoted the occurrence of Fenton-like reaction and enhance CDT efficacy.

The experimental results showed that PUNNC-mediated combined treatment of PTT&CDT can significantly increase the killing of tumor cells and inhibit the growth of tumor tissue.

This experiment demonstrated a kind of bifunctional nanotherapeutic based on NIR-II-responsive PUNNC for synergistic tumor therapy.