NanoXplore (Canada)

Abstract This work studied few‐layer graphene (FLG) dominant action mechanisms as a photo‐stabilizer. High‐density polyethylene (HDPE) containing 0–0.5 wt% FLG were exposed to UVA radiation in a QUV chamber, according to ASTM G154 for different exposure times, ranging from 0 to 672 h. The chemical, rheological, and mechanical properties were tracked using attenuated total reflection‐Fourier transform infrared (ATR‐FTIR), rheological measurements, and tensile tests. The experimental results showed that the addition of only 0.25 wt% FLG fully stabilized 1‐ to 3‐mm thick HDPE for an exposure time of 672 h. Electron paramagnetic resonance (EPR) test was performed on the UV‐exposed mixture of hydrogen peroxide (H2O2) and the FLG aqueous suspensions (0, 0.2, 1, and 5 mg/mL), to study the FLG performance and mechanisms as a photo‐stabilizer. The results showed that FLG effectively decreased the characteristic EPR signal intensity due to both UV absorption/reflection and free radical scavenging. Fifty‐seven percent of the reduction was found to be due to UV absorption/reflection and 43% due to free radical scavenging. It is demonstrated that UV absorption/reflection and free radical scavenging are the dominant ones among the three FLG photo‐stabilizing mechanisms (UV absorption/reflection, free radical scavenging, and physical barrier to oxygen).Highlights FLG showed potential as a photo‐stabilizer for HDPE. Addition of 0.25 wt% FLG fully stabilized HDPE for 672 h of UVA exposure. FLG demonstrated UV absorption/reflection and free radical scavenging effects.

Abstract Increasing outbreaks of new pathogenic viruses have promoted the exploration of novel alternatives to time-consuming vaccines. Thus, it is necessary to develop a universal approach to halt the spread of new and unknown viruses as they are discovered. One such promising approach is to target lipid membranes, which are common to all viruses and bacteria. The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has reaffirmed the importance of interactions between the virus envelope and the host cell plasma membrane as a critical mechanism of infection. Metadichol®, a nano lipid emulsion of long chain alcohols, has been demonstrated as a strong candidate that inhibits the proliferation of SARS-CoV-2. Naturally derived substances, such as long-chain saturated lipid alcohols, reduce viral infectivity, including that of coronaviruses (such as SARS-CoV-2) by modifying their lipid-dependent attachment mechanism to human host cells. The receptor ACE2 mediates the entry of SARS-CoV-2 into the host cells, whereas the serine protease TMPRSS2 primes the viral S protein. In this study, Metadichol® was found to be 270 times more potent an inhibitor of TMPRSS2 (EC50 = 96 ng/ml) than Camostat mesylate (EC50 = 26000 ng/mL). Additionally, it inhibits ACE with an EC50 of 71 ng/mL, but very weak inhibitor of ACE2 at an EC50 of 31 µg/ml. Furthermore, the live viral assay performed in Caco-2 cells revealed that Metadichol® inhibits SARS-CoV-2 replication at an EC90 of 0.16 µg/ml. Moreover, Metadichol® had an EC90 of 0.00037 µM, making it 2081 and 3371 times more potent than Remdesivir (EC50 = 0.77 µM) and chloroquine (EC50 = 1.14 µM), respectively.

Abstract New pathogenic virus outbreaks, occurring with increasing regularity, are leading us to explore novel approaches, which will reduce the reliance on time-consuming vaccine modes to halt the outbreaks. The requirement is to find a universal approach to disarm any new and as yet unknown viruses as they appear. A promising approach could be targeting lipid membranes, which are common to all viruses and bacteria.The ongoing pandemic of severe acute respiratory syndrome-coronavirus 2 (SARS-COV-2) has reaffirmed the importance of interactions between components of the host cell plasma membrane and the virus envelope as a critical mechanism of infection. Metadichol®, a nano lipid emulsion, has been examined and shown to be a strong candidate to help stop the proliferation of SARS-COV-2.Naturally derived substances, such as long-chain saturated lipid alcohols, reduce the infectivity of various types of viruses, including coronaviruses such as SARS-COV-2, by modifying lipid-dependent attachment to human host cells. SARS-COV-2 uses the receptor ACE2 for entry and the serine protease TMPRSS2 for S protein priming.Metadichol®, a nano lipid formulation of long-chain alcohols, has been shown to inhibit TMPRSS2 (EC50 96 ng/ml). Compared to the inhibitor camostat mesylate (EC50 26000 ng/ml), it is 270 times more potent. Additionally, Metadichol® is also a extremely weak inhibitor of ACE2 at 31 µg/ml. Further a live virus assay in Caco2 cells, Metadichol® inhibited SARS-CoV-2 replication with an EC90 of 0.16 µg/ml.

Production process was chosen in order to be readily scalable at the industrial level. The resin/graphene mixture was prepared through high shear mixing at six different weight concentrations between 0% and 10%. Samples were subsequently produced by compression molding. The electrical properties were measured both in-the-plane and across-the-plane using, respectively, a four-point probe and a two-electrode system. The two-electrode system was a dielectric spectrometer, and accordingly, the across-the-plane measurements were conducted in the frequency-domain. Mechanical measurements were conducted using conventional three-point bending and impact setups. The percolation threshold was found to be in the range of 3–5 wt.% concentration, for which the conductivity showed a 7 orders of magnitude increase. These results were quite similar to the samples containing around 50 wt.% of glass fibers. Surprisingly, the in-the-plane conductivity was found to be lower than the bulk conductivity, contrary to what was found with the same filler for thermoplastic composites prepared by melt compounding. No significant increase in mechanical properties as a function of filler loading was observed, except maybe a slight increase in the material toughness.