Near-Infrared Light-Triggered Chlorine Radical (. Cl) Stress for Cancer Therapy.

Free radicals with reactive chemical properties can fight tumors without causing drug resistance. Reactive oxygen species (ROS) has been widely used for cancer treatment, but regrettably, the common O2 and H2 O2 deficiency in tumors sets a severe barrier for sufficient ROS production, leading to unsatisfactory anticancer outcomes. Here, we construct a chlorine radical (. Cl) nano-generator with SiO2 -coated upconversion nanoparticles (UCNPs) on the inside and Ag0 /AgCl hetero-dots on the outside. Upon near-infrared (NIR) light irradiation, the short-wavelength emission UCNP catalyzes . Cl generation from Ag0 /AgCl with no dependence on O2 /H2 O2 . . Cl with strong oxidizing capacity and nucleophilicity can attack biomolecules in cancer cells more effectively than ROS. This . Cl stress treatment will no doubt broaden the family of oxidative stress-induced antitumor strategies by using non-oxygen free radicals, which is significant in the development of new anticancer agents.

Harnessing X-Ray Energy-Dependent Attenuation of Bismuth-Based Nanoprobes for Accurate Diagnosis of Liver Fibrosis.

Timely detection of liver fibrosis by X-ray computed tomography (CT) can prevent its progression to fatal liver diseases. However, it remains quite challenging because conventional CT can only identify the difference in density instead of X-ray attenuation characteristics. Spectral CT can generate monochromatic imaging to specify X-ray attenuation characteristics of the scanned matter. Herein, an X-ray energy-dependent attenuation strategy originated from bismuth (Bi)-based nanoprobes (BiF3 @PDA@HA) is proposed for the accurate diagnosis of liver fibrosis. Bi element in BiF3 @PDA@HA can exhibit characteristic attenuation depending on different levels of X-ray energy via spectral CT, and that is challenging for conventional CT. In this study, selectively accumulating BiF3 @PDA@HA nanoprobes in the hepatic fibrosis areas can significantly elevate CT value for 40 Hounsfield units on 70 keV monochromatic images, successfully differentiating from healthy livers and achieving the diagnosis of liver fibrosis. Furthermore, the enhancement produced by the BiF3 @PDA@HA nanoprobes in vivo increases as the monochromatic energy decreases from 70 to 40 keV, optimizing the conspicuity of the diseased areas. As a proof of concept, the strategically designed nanoprobes with energy-dependent attenuation characteristics not only expand the scope of CT application, but also hold excellent potential for precise imaging-based disease diagnosis.