Nature has always inspired robotic designs and concepts. It is conceivable that biomimic nanorobots will soon play a prominent role in medicine. The "Terminator" in the science fiction film is a cybernetic organism with living tissue over a metal endoskeleton, which inspired us to develop natural-killer-cell-mimic nanorobots with aggregation-induced emission (AIE) characteristics (NK@AIEdots) by coating a natural kill cell membrane on an AIE-active polymeric endoskeleton, PBPTV, a highly bright NIR-II AIE-active conjugated polymer. Owing to the AIE and soft-matter characteristics of PBPTV, as-prepared NK@AIEdots maintained a superior NIR-II brightness (quantum yield ∼7.9% in water) and good biocompatibility. Besides, they can serve as a tight junction (TJ) modulator to trigger an intracellular signaling cascade, causing TJ disruption and actin cytoskeleton reorganization to form an intercellular "green channel" to help them to cross the blood−brain barrier (BBB) silently. Furthermore, they can initiatively accumulate in glioblastoma cells in the complex brain matrix for highcontrast and through-skull tumor imaging. The tumor growth was also greatly inhibited by these NK@AIEdots under the NIR light illumination. As far as we know, the quantum yield of PBPTV is the highest among the existing NIR-II luminescent conjugated polymers. Besides, the NK-cell biomimetic nanorobots showed great potential for BBB-crossing active delivery.

Direct monitoring of cell death (i.e., apoptosis and necrosis) during or shortly after treatment is desirable in all cancer therapies to determine the outcome. Further differentiation of apoptosis from necrosis is crucial to optimize apoptosis-favored treatment protocols. We investigated the potential modality of using tissue intrinsic fluorescence chromophore, reduced nicotinamide adenine dinucleotide (NADH), for cell death detection. We imaged the fluorescence lifetime changes of NADH before and after staurosporine (STS)-induced mitochondria-mediated apoptosis and hydrogen peroxide (H2O2)-induced necrosis, respectively, using two-photon fluorescence lifetime imaging in live HeLa cells and 143B osteosarcoma. Time-lapsed lifetime images were acquired at the same site of cells. In untreated cells, the average lifetime of NADH fluorescence was approximately 1.3 ns. The NADH average fluorescence lifetime increased to approximately 3.5 ns within 15 min after 1 microM STS treatment and gradually decreased thereafter. The NADH fluorescence intensity increased within 15 min. In contrast, no significant dynamic lifetime change was found in cells treated with 1 mM H2O2. Our findings suggest that monitoring the NADH fluorescence lifetime may be a valuable noninvasive tool to detect apoptosis and distinguish apoptosis from necrosis for the optimization of apoptosis-favored treatment protocols and other clinical applications.

To develop efficient visible light driven photocatalysts for air purification, we constructed a novel semimetal−semiconductor Bi−Bi 2 MoO 6 (Bi−Mo) nanohybrid via the in situ deposition of Bi nanoparticles on the surface of Bi 2 MoO 6 microspheres. In this strategy, the Bi 3+ ions were in situ reduced to metallic Bi particles by glucose during in hydrothermal process. The XRD, XPS, SEM, TEM, UV−vis, DRS, PL spectra, and surface photovoltage were employed to explore the structural and optical properties. The assynthesized Bi−Bi 2 MoO 6 nanohybrid was applied in photocatalytic removal of NO in air. The results indicated that the amount of reductive glucose not only exerted a pivotal effect on the morphological structure but also affected the photocatalytic capability of the Bi−Bi 2 MoO 6 nanohybrid. The optimized Bi−Mo-50 hybrids exhibited exceptionally high visible-light photocatalytic performance with a NO removal ratio up to 68.1%, far outperforming other decent photocatalysts, like BiOBr (21.3%), C-doped TiO 2 (21.8%), N-doped TiO 2 (36.5%), N-doped (BiO) 2 CO 3 (43.5%), and g-C 3 N 4 (32.7%). This drastically enhanced photocatalytic capability was ascribed to the cocontributions of the enhanced light absorption and the improved separation efficiency of the charge carriers owing to the surface plasmon resonance (SPR) induced by Bi metal. The Bi metal performs as noble metal-like cocatalyst for promoting the photocatalysis efficiency. Based on the DMPO-ESR spin trapping, the active species generated from Bi/Bi 2 MoO 6 under visible light were • OH radicals. The Bi/Bi 2 MoO 6 produced more • OH radicals contributing to strengthen oxidation ability in comparison with that of the pristine Bi 2 MoO 6 . In addition, this advanced Bi/Bi 2 MoO 6 nanohybrid also exhibited high photochemical stability under repeated irradiation. This work demonstrated the feasibility of utilizing economical Bi element as a cocatalyst to substitute the precious noble metals to advance the photocatalysis efficiency.

No abstract

No abstract

The effect of refractory oxides on the oxidation of graphite and amorphous carbon was investigated. Al2O3 accelerated the oxidation of graphite greatly. TiO2, ZrO2, and MgO inhibited the oxidation of graphite, while SiO2 inhibited the oxidation of graphite slightly. The above oxides had no effect on the oxidation of amorphous carbon.

Persistent microbial infection and decreased neovascularization are common issues associated with diabetic wound treatment. Hydrogel dressings that offer intrinsic antibacterial and angiogenesis-inducing may substantially avoid the use of antibiotics or angiogenic agents. Herein, a versatile hydrogel is fabricated using an amyloid-derived toxin simulant (Fmoc-LFKFFK-NH 2 , FLN) as building blocks, inspired by the defense strategy of Staphylococcus aureus (S. aureus). The simulant assemblies of the hydrogel function as both matrix components and functional elements for diabetic wound treatment. The hydrogel undergoes quick assembly from random monomers to nanofibrils with abundant b-sheet driven by multiple non-covalent interactions. The developed hydrogel demonstrates excellent biocompatibility and accelerates angiogenesis via hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor A (VEGFA) signaling as a consequence of its amyloidal structure. The simulant-based nanofibrils endow the hydrogel with broad-spectrum antibacterial activity dominated by a membrane-disruption mechanism. In addition, the hydrogel exhibits excellent performance compared with the commercial hydrogel Prontosan in accelerating wound healing of diabetic mice infected with methicillinresistant S. aureus (MRSA). This study highlights the fabrication of a single component and versatile hydrogel platform, thereby avoiding the drugrelated side effects and complicated preparations and demonstrating its profound potential as a clinical dressing for the manage ment of microbeinfected diabetic wounds.

No abstract