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Escherichia coli is the most widely used protein production host in academia and a major host for industrial protein production. However, recombinant production of eukaryotic proteins in prokaryotes has challenges. One of these is post-translational modifications, including native disulfide bond formation. Proteins containing disulfide bonds have traditionally been made by targeting to the periplasm or by in vitro refolding of proteins made as inclusion bodies. More recently, systems for the production of disulfide-containing proteins in the cytoplasm have been introduced. However, it is unclear if these systems have the capacity for the production of disulfide-rich eukaryotic proteins. To address this question, we tested the capacity of one such system to produce domain constructs, containing up to 44 disulfide bonds, of the mammalian extracellular matrix proteins mucin 2, alpha tectorin, and perlecan. All were successfully produced with purified yields up to 6.5 mg/L. The proteins were further analyzed using a variety of biophysical techniques including circular dichroism spectrometry, thermal stability assay, and mass spectrometry. These analyses indicated that the purified proteins are most likely correctly folded to their native state. This greatly extends the use of E. coli for the production of eukaryotic proteins for structural and functional studies.

During the COVID-19 pandemic, the use of alcohol-based hand sanitizers (ABHS) increased worldwide among the public as well as the health care workers in pursuit to prevent the spread of SARS-CoV-2, the causative virus of COVID-19. Hand hygiene is one of the primary preventive measures to prevent the spread of harmful germs. Although ABHS are effective hand hygiene products and help reduce the transmission of pathogenic microorganisms, appropriate use of such products is necessary to ensure the maximum killing of pathogens and to prevent hazards associated with ABHS. The effectiveness of ABHS against different microorganisms, including SARS-CoV-2 is also documented, but proper knowledge on hand hygiene techniques, selection of appropriate hand sanitizer product, and safe handling of ABHS are required to avoid their adverse effects such as allergies, skin irritation, lung injury, fire hazards, and toxicities. The effectiveness of ABHS is dependent on several factors including its appropriate usage, manufacturing methods, the choice of active agents, and the appropriateness of the agent on the target pathogen. This article highlights the importance of proper usage, handling, and appropriate ABHS selection for maximum efficacy against intended pathogens and safe use of ABHS. User awareness can help promote the appropriate usage of ABHS and prevent its hazards, which ultimately can help in preventing the transmission of pathogenic microorganisms. Keywords Sanitizer, alcohol-based hand sanitizer, COVID-19, hand hygiene Introduction1The coronavirus disease-2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has highlighted the importance of preventive infection control measures in decreasing transmission, specifically: maintenance of proper hygiene, use of masks and other facial coverings, social distancing and self-isolation of patients presenting symptoms of acute respiratory

β-Lapachone has drawn increasing attention as an anti-inflammatory and anti-cancer drug. However, its oral bioavailability has not been yet assessed, which might be useful to develop efficient dosage forms possibly required for non-clinical and clinical studies and future market. The aim of the present study was thus to investigate pharmacokinetic properties of β-lapachone as well as its first-pass metabolism in the liver, and small and large intestines after oral administration to measure the absolute bioavailability in rats. A sensitive HPLC method was developed to evaluate levels of β-lapachone in plasma and organ homogenates. The drug degradation profiles were examined in plasma to assess the stability of the drug and in liver and intestinal homogenates to evaluate first-pass metabolism. Pharmacokinetic profiles were obtained after oral and intravenous administration of β-lapachone at doses of 40 mg/kg and 1.5 mg/kg, respectively. The measured oral bioavailability of β-lapachone was 15.5%. The considerable degradation of β-lapachone was seen in the organ homogenates but the drug was quite stable in plasma. In conclusion, we suggest that the fairly low oral bioavailability of β-lapachone may be resulted from the first-pass metabolic degradation of β-lapachone in the liver, small and large intestinal tracts and its low aqueous solubility.