A full-spectrum-absorption from nickel sulphide nanoparticles for efficient NIR-II window photothermal therapy.

Near-infrared (NIR) light has been widely applied in the field of photothermal therapy (PTT). Recent advances in the light wavelength for efficient cancer PTT have gradually shifted from the first NIR (NIR-I) biowindow (700-1000 nm) to the second NIR (NIR-II) biowindow (1000-1350 nm) owing to its intrinsic deeper tissue penetration ability and a higher maximum permissible exposure (MPE) value. Herein, we have prepared nickel sulphide (Ni9S8) nanoparticles (NPs) with a full-spectrum-absorption (400 nm-1100 nm) in the NIR region. By a fair comparison, it is found that the PTT using the NPs upon irradiation from an NIR-II (i.e., 1064 nm) laser is more efficient than that from an NIR-I (i.e., 808, 915, and 976 nm) laser. The large mass extinction coefficient value (22.18 L g-1 cm-1) and high photothermal conversion efficiency (46%) at 1064 nm make these NPs promising candidates for NIR-II photo-thermal therapy. This study will benefit future exploration and optimization of nickel-based photoabsorbers utilizing NIR-II light for photothermal applications.

New Strategy for Specific Eradication of Implant-Related Infections Based on Special and Selective Degradability of Rhenium Trioxide Nanocubes.

The greatest bottleneck for photothermal antibacterial therapy could be the difficulty in heating the infection site directly and specifically to evade the unwanted damage for surrounding healthy tissues. In recent years, infectious microenvironments (IMEs) have been increasingly recognized as a crucial contributor to bacterial infections. Here, based on the unique IMEs and rhenium trioxide (ReO3) nanocubes (NCs), a new specific photothermal antibacterial strategy is reported. These NCs synthesized by a rapid and straightforward space-confined on-substrate approach have good biocompatibility and exhibit efficient photothermal antibacterial ability. Especially when they are utilized in antibiofilm, the expression levels of biofilm-related genes (icaA, fnbA, atlE, and sarA for Staphylococcus aureus) can be effectively inhibited to block bacterial adhesion and formation of biofilm. Importantly, the ReO3 NCs can transform into hydrogen rhenium bronze (HxReO3) in an aqueous environment, making them relatively stable within the low pH of IMEs for photothermal therapy, while rapidly degradable within the surrounding healthy tissues to decrease photothermal damage. Note that under phosphate-buffered saline (PBS) at pH 7.4 without assistant conditions, these ReO3 NCs have the highest degradation rate among all known degradable inorganic photothermal nanoagents. This special and IME-sensitive selective degradability of the ReO3 NCs not only facilitates safe, efficient, and specific elimination of implant-related infections, but also enables effective body clearance after therapy. Solely containing the element (Re) whose atomic number is higher than clinic-applied iodine in all reported degradable inorganic photothermal nanoagents under the PBS (pH 7.4) without any assistant condition, the ReO3 NCs with high X-ray attenuation ability could be further applied to X-ray computed tomography imaging-guided therapy against implant-related infections. The present work described here is the first to adopt degradable inorganic photothermal nanoagents to achieve specific antibacterial therapy and inspires other therapies on this concept.