Calcium chloride enhances the delivery of exosomes.

Exosomes might have an unimproved potential to serve as effective delivery vehicles. However, when exosomes are developed for therapeutic applications, a method to enhance their delivery is important. This study aimed to evaluate wheather calcium chloride (CaCl2) or other chloride compounds could enhance exosome delivery to various cells without causing toxicity. Exosomes were purified from human serum by using the ExoQuick exosome precipitation kit. Isolated exosomes were mixed with CaCl2 at concentrations ranging from 100 μM to 1 mM, and then washed using Amicon filter for treating the cells. The delivery efficiency of exosomes and the viability of the cells [HEK 293 (human kidney cells) and H9C2 (rat cardiomyocytes)] were evaluated. Cellular uptake of exosomes was observed using a confocal microscope based on PKH26 labeling of exosomes. CaCl2 increased the delivery of exosomes in a dose- and treatment time-dependent manner. In HEK 293 cells, a CaCl2 concentration of 400 μM and exposure time of 12 h increased the delivery of exosomes by >20 times compared with controls. In H9C2 cells, a CaCl2 concentration of 400 μM and exposure time of >24 h increased the delivery of exosomes by >400 times compared with controls. The viability of both cell lines was maintained up to a CaCl2 concentration of 1 mM. However, cobalt chloride, cupric chloride, and magnesium chloride did not change the delivery of exosomes in both cell lines. These results suggest that the use of CaCl2 treatment might be a useful method for enhancing the delivery of exosomes

Three Component Controls in Pillared Metal-Organic Frameworks for Catalytic Carbon Dioxide Fixation

Three components of pillared metal-organic frameworks (MOFs, three components = metal ion, carboxylic acid ligand, and N-chelating ligand) were controlled for CO2 cycloaddition catalysts to synthesize organic cyclic carbonates. Among the divalent metals, Zn2+ showed the best catalytic activity, and in DABCO (1,4-diazabicyclo[2.2.2]octane)-based MOFs, hydroxy-functionalized DMOF-OH was the most efficient MOF for CO2 cycloaddition. For the BPY (4,4’-bipyridyl)-type MOFs, all five prepared BMOFs (BPY MOFs) showed similar and good conversions for CO2 cycloaddition. Finally, this pillared MOF could be recycled up to three times without activity and crystallinity loss

Augmented All-Optical Active Terahertz Device Using Graphene-Based Metasurface

Photo-excited graphene has a positive (semiconductor-like) or negative (metal-like) response depending on the Fermi level, which is tuned by gate control, doping, and growth. Both negative and positive photoconductive responses have a potential application as an ultrafast optical modulator in the control of light transmission. However, it is challenging to achieve a high on/off ratio in the photo-excited graphene because of a small absorption of electromagnetic waves and a limitation of photo-induced conductivity change. Here, the negative-type high on/off ratio and ultrafast terahertz modulation are experimentally demonstrated using graphene/metal nanoslot antennas. When the graphene covers the nanoslot antennas, the terahertz waves are completely blocked (off-state). This perfect extinction results from the enhanced intraband absorption in graphene by strong localized fields near the nanogap. However, once the optical pump is applied to the graphene/nanoslot antennas, terahertz transmission becomes recovered resonantly (on-state) due to the photo-induced transparency of graphene that leads to a distinctive modulation from off- to on-resonance. Furthermore, the fast carrier relaxation induced by strong terahertz field-driven carrier redistribution is responsible for the faster modulation of transient terahertz transmission. The results will open up pathways toward negative-response terahertz modulation applications with high on/off ratio and ultrafast time scale

The MARCHF6 E3 ubiquitin ligase acts as an NADPH sensor for the regulation of ferroptosis

Ferroptosis is a unique form of cell death caused by excessive iron-dependent lipid peroxidation. The level of the anabolic reductant NADPH is a biomarker of ferroptosis sensitivity. However, specific regulators that detect cellular NADPH levels, thereby modulating downstream ferroptosis cascades, are largely unknown. We show here that the transmembrane endoplasmic reticulum MARCHF6 E3 ubiquitin ligase recognizes NADPH through its C-terminal regulatory region. This interaction upregulates the E3 ligase activity of MARCHF6, thus downregulating ferroptosis. We also found that MARCHF6 mediates the degradation of the key ferroptosis effectors ACSL4 and p53. Furthermore, inhibiting ferroptosis rescued the growth of MARCHF6-deficient tumours and peri-natal lethality of Marchf6(-/-) mice. Together, these findings identify MARCHF6 as a previously unknown NADPH sensor in the ubiquitin system and a crucial regulator of ferroptosis. Nguyen et al. show that the E3 ubiquitin ligase MARCHF6 acts as an NADPH sensor to suppress ferroptosis. Mechanistically, NADPH binds to MARCHF6 and activates its E3 ligase activity, enhancing the degradation of pro-ferroptosis proteins.N