In the past decades, nanotechnology has stimulated a huge amount of interest and is now used in numerous fields. Carbon nanomaterials, like graphene, carbon nanotubes, and fullerenes, have attracted ...great attention for their widespread applications in diverse fields because of their excellent mechanical, optical, and thermal properties. With substantial production and use, potential human exposure to carbon nanomaterials is expected during the life cycle. To evaluate their biosafety, it is indispensable as a first step to quantify carbon nanomaterials in living organisms. In addition, it is essential to evaluate their interaction with biosystems, as the nano-bio interaction determines the nature and extent of toxic effects. This article reviews current research on techniques for quantifying carbon nanomaterials; dynamic processes including cellular uptake and exocytosis and the corresponding mechanisms; and interactions between cellular components and carbon nanomaterials. Recent biomedical applications of carbon nanomaterials are also described. To summarize, this review concludes with a comprehensive overview that summarizes the most important discoveries and progresses regarding three types of carbon nanomaterials and their derivatives.
Display omitted
Oxygen evolution reaction (OER) and urea oxidation reaction (UOR) limit the efficiency of electrolytic water and urea oxidation to hydrogen formation processes, respectively. Here, a facile ...low-temperature anhydrous method was used to synthesize NixFey-LDHs catalysts with good eletrocatalytic activity for OER and UOR. With urea oxidation as an alternative anodic reaction, the anodic oxidation potential decreased significantly to 1.37 V@20 mA cm−2. The electrolyzer voltage decreased to only 1.41 V@10 mA cm−2 with the Ni9Fe1-LDHs anode. It was demonstrated that Fe induced the formation of Ni(III) on the surface and promoted the reversible Ni(II)/Ni(III) transition.
Display omitted
•NixFey-LDH was synthesized by a facile low-temperature and anhydrous approach.•NixFey-LDH displays decent catalytic activity for OER and superior activity for urea oxidation.•The electrolyzer voltage decreases to only 1.41 V@10 mA cm−2 with the Ni9Fe1-LDH anode.•Fe induces Ni(III) species on surface and promote reversible transformation of Ni(II)/Ni(III).
Cellular uptake and exocytosis of SWCNTs are fundamental processes determining their intracellular concentration and effects. Despite the great potential of acid-oxidized SWCNTs in biomedical field, ...understanding of the influencing factors on these processes needs to be deepened. Here, we quantitatively investigated uptake and exocytosis of SWCNTs in three lengths-630 (±171) nm (L-SWCNTs), 390 (±50) nm (M-SWCNTs), and 195 (±63) nm (S-MWCNTs) in macrophages. The results showed that the cellular accumulation of SWCNTs was a length-independent process and non-monotonic in time, with the most SWCNTs (3950 fg/cell) accumulated at 8 h and then intracellular SWCNTs dropped obviously with time. The uptake rate of SWCNTs decreased with increasing concentration, suggesting that intracellular SWCNTs accumulation is a saturable process. After refreshing culture medium, we found increasing SWCNTs in supernatant and decreasing intracellular SWCNTs over time, confirming the exocytosis occurred. Selective inhibition of endocytosis pathways showed that the internalization of SWCNTs involves several pathways, in the order of macropinocytosis> caveolae-mediated endocytosis> clathrin-dependent endocytosis. Intriguingly, clathrin-mediated endocytosis is relatively important for internalizing shorter SWCNTs. The dynamic processes of SWCNTs uptake and exocytosis and the mechanisms revealed by this study may render a better understanding on SWCNT toxicity and facilitate the design of CNT products with mitigated toxicity and desired functions.
Abstract
Nonlinear optics provides a means to bridge between different electromagnetic frequencies, enabling communication between visible, infrared, and terahertz bands through
χ
(2)
and ...higher-order nonlinear optical processes. However, precisely modulating nonlinear optical waves in 3D space remains a significant challenge, severely limiting the ability to directly manipulate optical information across different wavelength bands. Here, we propose and experimentally demonstrate a three-dimensional (3D)
χ
(2)
-super-pixel hologram with nanometer resolution in lithium niobate crystals, capable of performing advanced processing tasks. In our design, each pixel consists of properly arranged nanodomain structures capable of completely and dynamically manipulating the complex-amplitude of nonlinear waves. Fabricated by femtosecond laser writing, the nonlinear hologram features a pixel diameter of 500 nm and a pixel density of approximately 25000 pixels-per-inch (PPI), reaching far beyond the state of the art. In our experiments, we successfully demonstrate the novel functions of the hologram to process near-infrared (NIR) information at visible wavelengths, including dynamic 3D nonlinear holographic imaging and frequency-up-converted image recognition. Our scheme provides a promising nano-optic platform for high-capacity optical storage and multi-functional information processing across different wavelength ranges.
Carbonic anhydrase (CA) IX overexpresses exclusively on cell membranes of hypoxic tumors, regulating the acidic tumor microenvironment. Small molecules of CA inhibitor modified with short peptide ...successfully achieve CA IX-targeted self-assembly that localizes CA inhibitors on hypoxic cancer cell surfaces and enhances their inhibition efficacy and selectivity. CA IX-related endocytosis also promotes selective intracellular uptake of these nanofibers under hypoxia, in which nanofiber structures increase in size with decreasing pH. This effect subsequently causes intracellular acid vesicle damage and blocks protective autophagy. The versatility of tunable nanostructures responding to cell milieu impressively provokes selective toxicities and provides strategic therapy for hypoxic tumors. Moreover, in vivo tests demonstrate considerable antimetastatic and antiangiogenesis effects in breast tumors, and particularly remarkable enhancement of antitumor efficacy in doxorubicin administration. With its biocompatible components and distinctive hypoxia therapies, this nanomaterial advances current chemotherapy, providing a new direction for hypoxic cancer therapy.
Hydrogen evolution reaction (HER), serving as the cathodic reaction of magnesium (Mg)/seawater battery, could not only produce clean hydrogen directly from seawater but also generate electricity. ...However, the kinetics of the hydrogen evolution directly from the neutral seawater is sluggish, and leads to unsatisfied HER and battery performance. Herein, a unique porous CoP/Co2P heterostructure electrode was fabricated via a template-free strategy. As demonstrated, the optimized porous CoP/Co2P heterostructure exhibits superior activity for HER, with low overpotential of 87, 133 and 454 mV at 10 mA cm−2 in acidic, alkaline and seawater media, respectively. An Mg/seawater battery fabricated with the porous CoP/Co2P heterostructure cathode displays promising performance, with a peak power density of 6.28 mW cm−2, approaching to the platinum cathode, and a satisfied stability in a 24 h stability test, which is the best non-noble metal cathode reported. The superior battery performance could be attributed to the large active interfaces and the high specific surface area of the porous CoP/Co2P heterostructure electrode, which guarantee a low polarization of the cathodic HER.
•The first demonstration of template-free synthesis porous CoP/Co2P heterostructure.•CoP/Co2P heterostructure is featured with porous structure and abundant interfaces.•CoP/Co2P heterostructure exhibits high HER and Mg/seawater battery performance.
Engineered nanomaterials (ENMs) are used in food additives, food packages, and therapeutic purposes owing to their useful properties, Therefore, human beings are orally exposed to exogenous ...nanomaterials frequently, which means the intestine is one of the primary targets of nanomaterials. Consequently, it is of great importance to understand the interaction between nanomaterials and the intestine. When nanomaterials enter into gut lumen, they inevitably interact with various components and thereby display different effects on the intestine based on their locations; these are known as location‐oriented effects (LOE). The intestinal LOE confer a new biological‐effect profile for nanomaterials, which is dependent on the involvement of the following biological processes: nano–mucus interaction, nano–intestinal epithelial cells (IECs) interaction, nano–immune interaction, and nano–microbiota interaction. A deep understanding of NM‐induced LOE will facilitate the design of safer NMs and the development of more efficient nanomedicine for intestine‐related diseases. Herein, recent progress in this field is reviewed in order to better understand the LOE of nanomaterials. The distant effects of nanomaterials coupling with microbiota are also highlighted. Investigation of the interaction of nanomaterials with the intestine will stimulate other new research areas beyond intestinal nanotoxicity.
The location‐oriented effects of engineered nanomaterials on the intestine and distant central nervous system are summarized. After entering the gut lumen, nanomaterials can interact with the mucus layer, intestinal epithelial cells, immunes cells, and gut microbiota. In addition, nanomaterials or intermediates produced by the nano–intestine interaction can further act on the central nervous system.
Exposure to atmospheric particulate matter (PM) is a frequent occurrence to humans, and their adverse outcomes have become a global concern. Although PM-induced inflammation is a common phenomenon, a ...clear picture of the mechanisms underlying exosome-mediated inflammation of PM has not yet emerged. Here, we show that exosomes can mediate the cascade reactions for the transfer of PM and inflammatory responses of macrophages. Specifically, two fine PM
, namely F1 (<0.49 μm) and F2 (0.95-1.5 μm), stimulated a substantial release of exosomes from macrophages (THP-1 cells) with the order of F1 > F2, via regulation of the P2X7 receptor (P2X7R). Inhibiting P2X7R with a specific inhibitor largely prevented the secretion of exosomes. In particular, we found that exosomes served as a mediator for the transfer of PM
to the recipient macrophages and activated NF-κB signaling through toll-like receptor 4 (TLR-4), thereby stimulating inflammatory cytokine release and altering the inflammatory phenotype of recipients. Importantly, the exosomes derived from PM
-treated macrophages induced the inflammatory responses of lung in mice. Our results highlight that exosomes undergo a secretion-particle transfer-adverse outcome chain in macrophages treated with PM
. Given the ubiquitous atmospheric particulate matter, these new findings underscore an urgent need for assessing the secretion of exosomes and their impact on human health via exosome-centric physiological pathways.
Distributed production of hydrogen peroxide (H2O2) via 2e-oxygen reduction reaction (ORR) has gained significant attention as a green and safe approach. In this work, black liquor-derived carbon is ...for the first time functionalized as an electrocatalyst for efficient H2O2 production. The oxygen and boron co-functionalized porous activated carbon (C3-O3-B10) exhibits high activity with almost zero overpotential for 2e-ORR, satisfactory H2O2 selectivity (77 %) and good stability. Mechanism investigations reveal that C3-O3-B10 favors catalyzing the 2e-ORR both thermodynamically and kinetically, with a low Tafel slope of 65 mV dec−1, fast charge transfer ability, and low apparent activation energy of 6.7 kJ mol−1 @ 0.4 VRHE, owing to the presence of abundant active CO and B-C2-O functional groups. This work demonstrates that the functionalized black liquor-derived carbon is a reliable and sustainable electrocatalyst to produce H2O2 via ORR, which provides new clues for the utilization of black liquor waste resources in the field of energy conversion and storage.
•Black liquor is used as the raw material to prepare a functionalized porous carbon compound.•BL-derived carbon is highly active to catalyze the 2e-oxygen reduction reaction to produce H2O2.•Almost zero overpotential for 2e-ORR, satisfactory H2O2 selectivity and good stability.•Low Tafel slope of 65 mV dec−1, fast charge transfer, low apparent activation energy of 6.7 kJ mol−1.•Abundant active CO and B-C2-O functional groups are responsible for superior performance.
PDF
