Metal-organic frameworks (MOFs) have been used for photodynamic therapy (PDT) of cancers by integrating photosensitizers, which cause cytotoxic effects on cancer cells by converting tumor oxygen into reactive singlet oxygen (O). However, the PDT efficiency of MOFs is severely limited by tumor hypoxia. Herein, by decorating platinum nanozymes on photosensitizer integrated MOFs, we report a simple yet versatile strategy for enhanced PDT. The platinum nanoparticles homogeneously immobilized on MOFs possess high stability and catalase-like activity. Thus, our nanoplatform can facilitate the formation of O in hypoxic tumor site via HO-activated evolvement of O, which can cause more serious damage to cancer cells. Our finding highlights that the composites of nanozymes and MOFs have the potential to serve as efficient agents for cancer therapy, which will open an avenue of nanozymes and MOFs toward biological applications.

Sea surface height measurements from satellites reveal the turbulent properties of the South Pacific Ocean surface geostrophic circulation, both supporting and challenging different aspects of geostrophic turbulence theory. A near-universal shape of the spectral kinetic energy flux is found and provides direct evidence of a source of kinetic energy near to or smaller than the deformation radius, consistent with linear instability theory. The spectral kinetic energy flux also reveals a net inverse cascade (i.e., a cascade to larger spatial scale), consistent with two-dimensional turbulence phenomenology. However, stratified geostrophic turbulence theory predicts an inverse cascade for the barotropic mode only; energy in the large-scale baroclinic modes undergoes a direct cascade toward the first-mode deformation scale. Thus if the surface geostrophic flow is predominately the first baroclinic mode, as expected for oceanic stratification profiles, then the observed inverse cascade contradicts geostrophic turbulence theory. The latter interpretation is argued for. Furthermore, and consistent with this interpretation, the inverse cascade arrest scale does not follow the Rhines arrest scale, as one would expect for the barotropic mode. A tentative revision of theory is proposed that would resolve the conflicts; however, further observations and idealized modeling experiments are needed to confirm, or refute, the revision. It is noted that no inertial range was found for the inverse cascade range of the spectrum, implying inertial range scaling, such as the established K−5/3 slope in the spectral kinetic energy density plot, is not applicable to the surface geostrophic flow.

The fabrication of functional nanoplatforms for combating multidrugresistant bacteria is of vital importance. Among them, silver nanoparticles (Ag NPs) have shown an antibacterial effect; however, the remainder cores of Ag NPs after use might have a toxic effect on humans. Thus, Ag ions based materials have been fabricated to substitute Ag NPs for antibacterial applications. Nevertheless, the always-on release state leads to the low biocompatibility, which limits their biomedical applications. In addition, the single effect also restricts their antibacterial ability. Herein, a powerful surface-adaptive, on-demand antimicrobial nanoplatform is fabricated by coating hyaluronic acid (HA) on Ag ions loaded photosensitive metal-organic frameworks to exhibit a strong synergistic effect. The nanoplatform shows good biocompatibility with nontargeted cells, as negatively charged HA can prevent the release of Ag ions. While in the presence of targeted bacteria, the secreted hyaluronidase can degrade HA on the nanoplatform and produce positively charged nanoparticles, which display increased affinity to bacteria and show a strong synergistic antibacterial effect owing to the released Ag ions and generated reactive oxygen species under visible light irradiation. Importantly, due to the outstanding on-demand antimicrobial performance, the nanoplatform also shows great effects on treating multidrug-resistant bacteria infected wounds in mice models.