Safety Assessment of the Modified Lactoperoxidase System-In Vitro Studies on Human Gingival Fibroblasts.

One strategy in caries prevention is to inhibit the formation of cariogenic biofilms. Attempts are being made to develop oral hygiene products enriched with various antimicrobial agents. One of them is lactoperoxidase-an enzyme that can oxidise (pseudo)halide ions to reactive products with antimicrobial activity. Currently, commercially available products utilise thiocyanate as a substrate; however, several alternatives that are oxidised to products with greater antimicrobial potential have been found. In this study, toxicity against human gingival fibroblasts of the lactoperoxidase system was evaluated using four different (pseudo)halide substrate systems-thiocyanate, iodide, selenocyanate, and a mixture of thiocyanate and iodide. For this purpose, cells were treated with the systems and then apoptosis, cell cycle, intracellular glutathione concentration, and mitochondrial superoxide production were assessed. The results showed that each system, after generating 250 µM of the product, inhibited cell divisions, increased apoptosis, and increased the percentage of dead cells. It was concluded that the mechanism of the observed phenomena was not related to increased superoxide production or the depletion of glutathione concentration. These findings emphasised the need for the further in vitro and in vivo toxicity investigation of the modified lactoperoxidase system to assess its safety and the possibility of use in oral hygiene products.

Inhibition of the Cell Uptake of Delta and Omicron SARS-CoV-2 Pseudoviruses by N-Acetylcysteine Irrespective of the Oxidoreductive Environment.

The binding of SARS-CoV-2 spikes to the cell receptor angiotensin-converting enzyme 2 (ACE2) is a crucial target both in the prevention and in the therapy of COVID-19. We explored the involvement of oxidoreductive mechanisms by investigating the effects of oxidants and antioxidants on virus uptake by ACE2-expressing cells of human origin (ACE2-HEK293). The cell uptake of pseudoviruses carrying the envelope of either Delta or Omicron variants of SARS-CoV-2 was evaluated by means of a cytofluorimetric approach. The thiol N-acetyl-L-cysteine (NAC) inhibited the uptake of both variants in a reproducible and dose-dependent fashion. Ascorbic acid showed modest effects. In contrast, neither hydrogen peroxide (H2O2) nor a system-generating reactive oxygen species (ROS), which play an important role in the intracellular alterations produced by SARS-CoV-2, were able to affect the ability of either Delta or Omicron SARS-CoV-2 pseudoviruses to be internalized into ACE2-expressing cells. In addition, neither H2O2 nor the ROS generating system interfered with the ability of NAC to inhibit that mechanism. Moreover, based on previous studies, a preventive pharmacological approach with NAC would have the advantage of decreasing the risk of developing COVID-19, irrespective of its variants, and at the same time other respiratory viral infections and associated comorbidities.

Biological Efficacy of Compounds from Stingless Honey and Sting Honey against Two Pathogenic Bacteria: An In Vitro and In Silico Study.

Honey inhibits bacterial growth due to the high sugar concentration, hydrogen peroxide generation, and proteinaceous compounds present in it. In this study, the antibacterial activity of stingless and sting honey against foodborne pathogenic bacteria isolated from spoiled milk samples was examined. The isolated bacterial strains were confirmed as Bacillus cereus and Listeriamonocytogenes through morphological, biochemical, and 16 s RNA analysis. Physiochemical characterizations of the honey samples revealed that both of the honey samples had an acidic pH, low water content, moderate reducing sugar content, and higher proline content. Through the disc diffusion method, the antibacterial activities of the samples were assayed and better results were observed for the 50 mg/disc honey. Both stingless and sting honey showed the most positive efficacy against Bacillus cereus. Therefore, an in silico study was conducted against this bacterium with some common compounds of honey. From several retrieved constituents of stingless and sting honey, 2,4-dihydroxy-2,5-dimethyl 3(2H)-furan-3-one (furan) and 4H-pyran-4-one,2,3-dihydro of both samples and beta.-D-glucopyranose from the stingless revealed high ligand-protein binding efficiencies for the target protein (6d5z, hemolysin II). The root-mean-square deviation, solvent-accessible surface area, the radius of gyration, root-mean-square fluctuations, and hydrogen bonds were used to ensure the binding stability of the docked complexes in the atomistic simulation and confirmed their stability. The combined effort of wet and dry lab-based work support, to some extent, that the antimicrobial properties of honey have great potential for application in medicine as well as in the food industries.

Evaluation of quality and antimicrobial efficacy of locally manufactured alcohol-based hand sanitizers marketed in Addis Ababa, Ethiopia in the era of COVID-19.

BACKGROUND: The coronavirus disease 2019 (COVID-19) has been rapidly spreading across the globe since the World Health Organization (WHO) has declared the disease outbreak as a global pandemic on March 11, 2020. Hand hygiene, via either regular handwashing with soap and water or using hand sanitizers, is among the various measures that need to be followed to control the outbreak of the disease. Alcohol-based hand sanitizers (ABHS) are the "gold standard" for hand disinfection because of their broad antimicrobial spectrum of activity, easy availability, better safety profile, and general acceptability to users. This study aimed at evaluating the physicochemical quality and antimicrobial efficacy of the locally manufactured ABHS marketed in Addis Ababa, Ethiopia. METHODS: A cross-sectional survey was used to collect ABHS from Addis Ababa marketplaces. A total of 25 sample products were randomly selected from different categories of hand sanitizer manufacturers. The physicochemical evaluation of the products was carried out as per the United States Pharmacopoeia and WHO standards. Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella spp., and Shigella spp clinical isolates were used for the antimicrobial efficacy test. RESULTS: The Fourier Transform Infrared result confirmed that all the test products met the identification test for ethanol. The majority (68%) of ABHS complied with the test for ethanol content (75-85% v/v). However, only 3 products fulfilled the hydrogen peroxide content (0.112-0.137% v/v). LPC307 showed the maximum zone of inhibition of 12 mm against Escherichia coli whereas MPC204 exhibited only 3 mm. LPC101 was found to be more sensitive to Shigella and Klebsiella Spp with minimum inhibitory concentration values of 20% and 10%, respectively. The sample product LPC101 showed a minimum bactericidal concentration of 20% against Escherichia coli, Pseudomonas aeruginosa, and Klebsiella spp. CONCLUSION: One-third of the tested ABHS did not comply with the WHO ethanol content limit and the majority of the products failed to meet the label claim for hydrogen peroxide content. Besides, nearly all products proved that they have activity against all the tested pathogenic microorganisms at a minimum concentration from 10 to 80%; though, they did not show 99.9% bacteriostatic or bactericidal activities as claimed. The study findings suggested regular monitoring of the quality of marketed ABHS considering the current wide use of these products.

Aerosolized Hydrogen Peroxide Decontamination of N95 Respirators, with Fit-Testing and Viral Inactivation, Demonstrates Feasibility for Reuse during the COVID-19 Pandemic.

In response to the demand for N95 respirators by health care workers during the COVID-19 pandemic, we evaluated decontamination of N95 respirators using an aerosolized hydrogen peroxide (aHP) system. This system is designed to dispense a consistent atomized spray of aerosolized, 7% hydrogen peroxide (H₂O₂) solution over a treatment cycle. Multiple N95 respirator models were subjected to 10 or more cycles of respirator decontamination, with a select number periodically assessed for qualitative and quantitative fit testing. In parallel, we assessed the ability of aHP treatment to inactivate multiple viruses absorbed onto respirators, including phi6 bacteriophage, herpes simplex virus 1 (HSV-1), coxsackievirus B3 (CVB3), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For pathogens transmitted via respiratory droplets and aerosols, it is critical to address respirator safety for reuse. This study provided experimental validation of an aHP treatment process that decontaminates the respirators while maintaining N95 function. External National Institute for Occupational Safety & Health (NIOSH) certification verified respirator structural integrity and filtration efficiency after 10 rounds of aHP treatment. Virus inactivation by aHP was comparable to the decontamination of commercial spore-based biological indicators. These data demonstrate that the aHP process is effective, with successful fit-testing of respirators after multiple aHP cycles, effective decontamination of multiple virus species, including SARS-CoV-2, successful decontamination of bacterial spores, and filtration efficiency maintained at or greater than 95%. While this study did not include extended or clinical use of N95 respirators between aHP cycles, these data provide proof of concept for aHP decontamination of N95 respirators before reuse in a crisis-capacity scenario. IMPORTANCE The COVID-19 pandemic led to unprecedented pressure on health care and research facilities to provide personal protective equipment. The respiratory nature of the SARS-CoV2 pathogen makes respirator facepieces a critical protective measure to limit inhalation of this virus. While respirator facepieces were designed for single use and disposal, the pandemic increased overall demand for N95 respirators, and corresponding manufacturing and supply chain limitations necessitated the safe reuse of respirators when necessary. In this study, we repurposed an aerosolized hydrogen peroxide (aHP) system that is regularly utilized to decontaminate materials in a biosafety level 3 (BSL3) facility, to develop a method for decontamination of N95 respirators. Results from viral inactivation, biological indicators, respirator fit testing, and filtration efficiency testing all indicated that the process was effective at rendering N95 respirators safe for reuse. This proof-of-concept study establishes baseline data for future testing of aHP in crisis-capacity respirator-reuse scenarios.

Efficacy of hydrogen peroxide wipes for decontamination of AZD1222 adenovirus COVID-19 vaccine strain on pharmaceutical industry materials.

This study aimed to evaluate the performance of accelerated hydrogen peroxide® wipes (HPW) for decontamination of the chimpanzee adenovirus AZD1222 vaccine strain used in the production of recombinant COVID-19 vaccine in a pharmaceutical industry. Two matrices were tested on stainless-steel (SS) and low-density-polyethylene (LDP) surfaces: formulated recombinant COVID-19 vaccine (FCV) and active pharmaceutical ingredient (API). The samples were spiked, dried and the initial inoculum, possible residue effect (RE) and titre reduction after disinfection with HPW were determined. No RE was observed. The disinfection procedure with HPW resulted in complete decontamination the of AZD1222 adenovirus strain in FCV (≥7·46 and ≥7·49 log10 infectious unit [IFU] ml-1 for SS and LDP carriers respectively) and API (≥8·79 and ≥8·78 log10 IFU ml-1 for SS and LDP carriers respectively). In conclusion, virucidal activity of HPW was satisfactory against the AZD1222 adenovirus strain and can be a good option for disinfection processes of SS and LPD surfaces in pharmaceutical industry facilities during recombinant COVID-19 vaccine production. This procedure is simple and can be also applied on safety unit cabins and sampling bags made of LDP as well.

New trends in application of the fumigation method in medical and non-medical fields.

INTRODUCTION: In the twentieth century, fumigation became a very popular method of disinfection, although in the same century many agents used as fumigants were withdrawn for ecological reasons. Fogging (fumigation) is a relatively new disinfection technology using dry fog, which behaves more like a gas and easily fills the sanitized space, reaching all surfaces in the room. The undoubted advantage of fumigation is the possibility of disinfecting difficult to clean areas. Fumigation has become particularly important in the twenty-first century due to procedures related to combating and preventing the spread of the coronavirus that causes COVID-19. OBJECTIVE: The aim of this review article is to summarize the current state of knowledge in the field of fumigation on the basis of past results of original research, taking into account new trends and possibilities of its application. BRIEF DESCRIPTION OF THE STATE OF KNOWLEDGE: Due to the fact that fumigation is safe for apparatus, equipment, and electronics, while simultaneously enabling the highest possible bactericidal and virucidal levels, this method is widely used in various areas, both medical and non-medical. Fogging technology is used in the medical, pharmaceutical, and food industries, as well as in transportation, for air fumigation or surface disinfection in closed spaces, such as hospital and laboratory rooms, incubators, refrigerators, ships, trucks, railway containers, and aircraft, to name only a few. The most common fumigants are hydrogen peroxide and peracetic acid, and their mechanism of action is related to their oxidizing properties. SUMMARY: Hydrogen peroxide and peracetic acid are highly effective and non-toxic fumigants that can be safely used for fogging laboratory and medical equipment, pharmaceutical facilities, hospital rooms, and animal breeding rooms.

Cellulosic copper nanoparticles and a hydrogen peroxide-based disinfectant trigger rapid inactivation of pseudoviral particles expressing the Spike protein of SARS-CoV-2, SARS-CoV, and MERS-CoV.

Severe acute respiratory syndrome (SARS) is a viral respiratory infection caused by human coronaviruses that include SARS-CoV-2, SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV). Although their primary mode of transmission is through contaminated respiratory droplets from infected carriers, the deposition of expelled virus particles onto surfaces and fomites could contribute to viral transmission. Here, we use replication-deficient murine leukemia virus (MLV) pseudoviral particles expressing SARS-CoV-2, SARS-CoV, or MERS-CoV Spike (S) protein on their surface. These surrogates of native coronavirus counterparts serve as a model to analyze the S-mediated entry into target cells. Carboxymethyl cellulose (CMC) nanofibers that are combined with copper (Cu) exhibit strong antimicrobial properties. S-pseudovirions that are exposed to CMC-Cu nanoparticles (30 s) display a dramatic reduction in their ability to infect target Vero E6 cells, with ∼97% less infectivity as compared to untreated pseudovirions. In contrast, addition of the Cu chelator tetrathiomolybdate protects S-pseudovirions from CMC-Cu-mediated inactivation. When S-pseudovirions were treated with a hydrogen peroxide-based disinfectant (denoted SaberTM) used at 1:250 dilution, their infectivity was dramatically reduced by ∼98%. However, the combined use of SaberTM and CMC-Cu is the most effective approach to restrict infectivity of SARS-CoV-2-S, SARS-CoV-S, and MERS-CoV-S pseudovirions in Vero E6 cell assays. Together, these results show that cellulosic Cu nanoparticles enhance the effectiveness of diluted SaberTM sanitizer, setting up an improved strategy to lower the risk of surface- and fomite-mediated transmission of enveloped respiratory viruses.

Use of a Hydrogen Peroxide Nebulizer for Viral Disinfection of Emergency Ambulance and Hospital Waiting Room.

Disinfection of hospital facilities and ambulances is an important issue for breaking the chain of transmission of viral pathogens. Hydrogen peroxide has provided promising results in laboratory assays. Here, we evaluate the efficacy of a hydrogen peroxide nebulizer for the inactivation of surrogate MS2 bacteriophage and murine norovirus (MNV) in a patient waiting room and the fully equipped cabin of a medical ambulance. We observed an average 3 log10 titer reduction in both settings, which represents the destruction of over 106 and 109 infectious particles of MNV and MS2 per cm2, respectively. The potential for viral exposure is high for health workers when disinfecting confined and cluttered spaces, so the use of a hydrogen peroxide mist might offer an affordable and efficient solution to minimize the risk of viral contaminations.

Inactivation of SARS-CoV-2 and influenza A virus by dry fogging hypochlorous acid solution and hydrogen peroxide solution.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is transmitted mainly by droplet or aerosol infection; however, it may also be transmitted by contact infection. SARS-CoV-2 that adheres to environmental surfaces remains infectious for several days. We herein attempted to inactivate SARS-CoV-2 and influenza A virus adhering to an environmental surface by dry fogging hypochlorous acid solution and hydrogen peroxide solution. SARS-CoV-2 and influenza virus were air-dried on plastic plates and placed into a test chamber for inactivation by the dry fogging of these disinfectants. The results obtained showed that the dry fogging of hypochlorous acid solution and hydrogen peroxide solution inactivated SARS-CoV-2 and influenza A virus in CT value (the product of the disinfectant concentration and contact time)-dependent manners. SARS-CoV-2 was more resistant to the virucidal effects of aerosolized hypochlorous acid solution and hydrogen peroxide solution than influenza A virus; therefore, higher concentrations of disinfectants or longer contact times were required to inactivate SARS-CoV-2 than influenza A virus. The present results provide important information for the development of a strategy that inactivates SARS-CoV-2 and influenza A virus on environmental surfaces by spatial fogging.

Unfolding the effects of decontamination treatments on the structural and functional integrity of N95 respirators via numerical simulations.

Filtering facepiece respirators (FFRs) provide effective protection against diseases spread through airborne infectious droplets and particles. The widespread use of FFRs during the COVID-19 pandemic has not only led to supply shortages, but the disposal of single-use facemasks also threatens the environment with a new kind of plastic pollution. While limited reuse of filtering facepiece respirators has been permitted as a crisis capacity strategy, there are currently no standard test methods available for decontamination before their repeated use. The decontamination of respirators can compromise the structural and functional integrity by reducing the filtration efficiency and breathability. Digital segmentation of X-ray microcomputed tomography (microCT) scans of the meltblown nonwoven layers of a specific N95 respirator model (Venus-4400) after treatment with one and five cycles of liquid hydrogen peroxide, ultraviolet radiation, moist heat, and aqueous soap solution enabled us to perform filtration simulations of decontaminated respirators. The computed filtration efficiencies for 0.3 µm particles agreed well with experimental measurements, and the distribution of particle penetration depths was correlated with the structural changes resulting from decontamination. The combination of X-ray microCT imaging with numerical simulations thus provides a strategy for quantitative evaluation of the effectiveness of decontamination treatments for a specific respirator model.

Large-scale decontamination of disposable FFP2 and FFP3 respirators by hydrogen peroxide vapour, Finland, April to June 2020.

BackgroundThe shortage of FFP2 and FFP3 respirators posed a serious threat to the operation of the healthcare system at the onset of the COVID-19 pandemic.AimOur aim was to develop and validate a large-scale facility that uses hydrogen peroxide vapour for the decontamination of used respirators.MethodsA multidisciplinary and multisectoral ad hoc group of experts representing various organisations was assembled to implement the collection and transport of used FFP2 and FFP3 respirators from hospitals covering 86% of the Finnish population. A large-scale decontamination facility using hydrogen peroxide vapour was designed and constructed. Microbiological tests were used to confirm efficacy of hydrogen peroxide vapour decontamination together with a test to assess the effect of decontamination on the filtering efficacy and fit of respirators. Bacterial and fungal growth in stored respirators was determined by standard methods.ResultsLarge-scale hydrogen peroxide vapour decontamination of a range of FFP2 and FFP3 respirator models effectively reduced the recovery of biological indicators: Geobacillus stearothermophilus and Bacillus atrophaeus spores, as well as model virus bacteriophage MS2. The filtering efficacy and facial fit after hydrogen peroxide vapour decontamination were not affected by the process. Microbial growth in the hydrogen peroxide vapour-treated respirators indicated appropriate microbial cleanliness.ConclusionsLarge-scale hydrogen peroxide vapour decontamination was validated. After effective decontamination, no significant changes in the key properties of the respirators were detected. European Union regulations should incorporate a facilitated pathway to allow reuse of appropriately decontaminated respirators in a severe pandemic when unused respirators are not available.

Evaluation of hydrogen peroxide efficacy against AZD1222 chimpanzee adenovirus strain in the recombinant COVID-19 vaccine for application in cleaning validation in a pharmaceutical manufacturing industry.

This study aimed to evaluate the performance of hydrogen peroxide vapour (HPV) to inactivate the chimpanzee adenovirus AZD1222 vaccine strain used in the production of recombinant COVID-19 vaccine for application in cleaning validation in pharmaceutical industries production areas. Two matrixes were tested: formulated recombinant COVID-19 vaccine (FCV) and active pharmaceutical ingredient (API). The samples were dried on stainless steel and exposed to HPV in an isolator. One biological indicator with population >106 Geobacillus stearothermophilus spores was used to validate the HPV decontamination cycle as standard. HPV exposure resulted in complete virus inactivation in FVC (≥5·03 log10 ) and API (≥6·40 log10 ), showing HPV efficacy for reducing chimpanzee adenovirus AZD1222 vaccine strain. However, the optimum concentration and contact time will vary depending on the type of application. Future decontamination studies scaling up the process to the recombinant COVID-19 vaccine manufacturing areas are necessary to evaluate if the HPV will have the same or better virucidal effectivity in each specific production area. In conclusion, HPV showed efficacy for reducing AZD1222 chimpanzee adenovirus strain and can be a good choice for pharmaceutical industries facilities disinfection during recombinant COVID-19 vaccine production.

Viral Inactivation with Emphasis on SARS-CoV-2 Using Physical and Chemical Disinfectants.

BACKGROUND: Recently, an outbreak of a novel human coronavirus SARS-CoV-2 has become a world health concern leading to severe respiratory tract infections in humans. Virus transmission occurs through person-to-person contact, respiratory droplets, and contaminated hands or surfaces. Accordingly, we aim at reviewing the literature on all information available about the persistence of coronaviruses, including human and animal coronaviruses, on inanimate surfaces and inactivation strategies with biocides employed for chemical and physical disinfection. METHOD: A comprehensive search was systematically conducted in main databases from 1998 to 2020 to identify various viral disinfectants associated with HCoV and methods for control and prevention of this newly emerged virus. RESULTS: The analysis of 62 studies shows that human coronaviruses such as severe acute respiratory syndrome (SARS) coronavirus, Middle East respiratory syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV), canine coronavirus (CCV), transmissible gastroenteritis virus (TGEV), and mouse hepatitis virus (MHV) can be efficiently inactivated by physical and chemical disinfectants at different concentrations (70, 80, 85, and 95%) of 2-propanol (70 and 80%) in less than or equal to 60 s and 0.5% hydrogen peroxide or 0.1% sodium hypochlorite within 1 minute. Additionally, glutaraldehyde (0.5-2%), formaldehyde (0.7-1%), and povidone-iodine (0.1-0.75%) could readily inactivate coronaviruses. Moreover, dry heat at 56°C, ultraviolet light dose of 0.2 to 140 J/cm2, and gamma irradiation could effectively inactivate coronavirus. The WHO recommends the use of 0.1% sodium hypochlorite solution or an ethanol-based disinfectant with an ethanol concentration between 62% and 71%. CONCLUSION: The results of the present study can help researchers, policymakers, health decision makers, and people perceive and take the correct measures to control and prevent further transmission of COVID-19. Prevention and decontamination will be the main ways to stop the ongoing outbreak of COVID-19.

In vitro comparison of the tensile strength of elastomeric ligatures exposed to Povidone Iodine 1%, Chlorhexidine 0.02%, and hydrogen peroxide 5.

OBJECTIVE: In orthodontic patients using any chemical substances in oral environment could change the elastomeric properties of their appliances. Since the beginning of the SARS-CoV-2 pandemic, efforts have been devoted to explore methods of prevention including the use of antiviral mouthwashes. This study aimed to investigate the effects of Povidone Iodine (PVP-I) and two other disinfecting solutions on the mechanical properties of orthodontic elastomeric ligatures. MATERIALS AND METHODS: In this study, 130 elastomeric ligatures in five groups (three test groups and two control groups) were examined in laboratory conditions for a period of 28 days. In the control group, specimens were kept dry in a dark environment while all other ligatures were stored in artificial saliva. Elastomeric ligatures were immersed into PVP-I solution (1%) Chlorhexidine (0.02%), and hydrogen peroxide (5%) for one minute each day in three time intervals of one day, 7 days and 28 days. Next, the maximum tensile strength of elastomeric ligatures was tested by a universal testing machine (CN 1174, Germany). RESULTS: The results showed that the tensile strength of elastomeric ligatures was significantly decreased in all three test groups after 28 days (p-value<0.05). However, the difference between groups was not statistically significant. Between-subject ANOVA test showed that there were significant correlations between the time of exposure and type of disinfecting solutions. CONCLUSIONS: PVP-I has comparable effects on elastomeric ligatures as artificial saliva, chlorhexidine, and hydrogen peroxide.

Decontamination of respirators amid shortages due to SARS-CoV-2.

The pandemic created by SARS-CoV-2 has caused a shortage in the supplies of N95 filtering facepiece respirators (FFRs), disposable respirators with at least 95% efficiency to remove non-oily airborne particles, due to increasing cases all over the world. The current article reviewed various possible decontamination methods for FFR reuse including ultraviolet germicidal irradiation (UVGI), hydrogen peroxide vapor (HPV), microwave-generated steam (MGS), hydrogen peroxide gas plasma (HPGP), and 70% or higher ethanol solution. HPV decontamination was effective against bacterial spores (6 log10 reduction of Geobacillus stearothermophilus spores) on FFRs and viruses (> 4 log10 reduction of various types of viruses) on inanimate surfaces, and no degradation of respirator materials and fit has been reported. 70% or higher ethanol decontamination showed high efficacy in inactivation of coronaviruses on inanimate surfaces (> 3.9 log10 reduction) but it was lower on FFRs which filtration efficiency was also decreased. UVGI method had good biocidal efficacy on FFRs (> 3 log10 reduction of H1N1 virus) combined with inexpensive, readily available equipment; however, it was more time-consuming to ensure sufficient reduction in SARS-CoV-2. MGS treatment also provided good viral decontamination on FFRs (> 4 log10 reduction of H1N1 virus) along with less time-intensive process and readily available equipment while inconsistent disinfection on the treated surfaces and deterioration of nose cushion of FFRs were observed. HPGP was a good virucidal system (> 6 log10 reduction of Vesicular stomatitis virus) but filtration efficiency after decontamination was inconsistent. Overall, HPV appeared to be one of the most promising methods based on the high biocidal efficacy on FFRs, preservation of respirator performance after multiple cycles, and no residual chemical toxicity. Nonetheless, equipment cost and time of the HPV process and a suitable operating room need to be considered.

Antiviral effect of multipurpose contact lens disinfecting solutions against coronavirus.

PURPOSE: To evaluate the antiviral potential of five multipurpose disinfecting solutions against coronavirus (mouse hepatitis virus, a surrogate for SARS-CoV-2 human corona virus). METHODS: Test solutions (Biotrue, renu Advanced [Bausch and Lomb], ACUVUE RevitaLens [Johnson and Johnson Vision], cleadew [Ophtecs corp.] or AOSept Plus [Alcon]) were mixed with the coronavirus mouse hepatitis virus at 104 plaque forming units (PFU)/mL as the final concentration and incubated at room temperature for the specified disinfection time. Surviving virus from each sample was then quantified by standard plaque forming unit assay and the reduction of PFU for each disinfectant was compared to the phosphate buffer saline (PBS) treated negative control. A regimen test was also conducted using Biotrue. RESULTS: The three multipurpose disinfecting solutions Biotrue (containing PHMB and polyquaternium-1), renu Advanced (PHMB, polyquaternium-1 and alexidine) and ACUVUE RevitaLens (polyquaternium-1 and alexidine) did not kill the coronavirus at the manufacturers recommended disinfection time in the stand alone test. After treatment, the virus's titer (3.8 ± 0.2 log10 for Biotrue, 3.7 ± 0.1 log10 for renu and 3.7 ± 0.2 log10 for RevitaLens) was similar to the negative control (3.7 ± 0.1 log10; p ≥ 0.996). AOSept Plus (hydrogen peroxide) and cleadew (povidone iodine) significantly (p < 0.001) reduced the numbers of coronaviruses to below the detection limit (i.e. killed 3.7 ± 0.1 log10 viruses compared to control). However, there was a significant reduction (p = 0.028) in numbers of coronaviruses attached to lenses when using the regimen test with Biotrue. CONCLUSIONS: This study shows that oxidative contact lens disinfecting solutions (i.e. those containing povidone-iodine or hydrogen peroxide) provide superior antiviral activity against a coronavirus surrogate of SARS-CoV-2, unless the full regimen test (rub, rinse, disinfect) is used.

Leonurine Ameliorates Oxidative Stress and Insufficient Angiogenesis by Regulating the PI3K/Akt-eNOS Signaling Pathway in H2O2-Induced HUVECs.

Thrombus is considered to be the pathological source of morbidity and mortality of cardiovascular disease and thrombotic complications, while oxidative stress is regarded as an important factor in vascular endothelial injury and thrombus formation. Therefore, antioxidative stress and maintaining the normal function of vascular endothelial cells are greatly significant in regulating vascular tension and maintaining a nonthrombotic environment. Leonurine (LEO) is a unique alkaloid isolated from Leonurus japonicus Houtt (a traditional Chinese medicine (TCM)), which has shown a good effect on promoting blood circulation and removing blood stasis. In this study, we explored the protective effect and action mechanism of LEO on human umbilical vein endothelial cells (HUVECs) after damage by hydrogen peroxide (H2O2). The protective effects of LEO on H2O2-induced HUVECs were determined by measuring the cell viability, cell migration, tube formation, and oxidative biomarkers. The underlying mechanism of antioxidation of LEO was investigated by RT-qPCR and western blotting. Our results showed that LEO treatment promoted cell viability; remarkably downregulated the intracellular generation of reactive oxygen species (ROS), malondialdehyde (MDA) production, and lactate dehydrogenase (LDH); and upregulated the nitric oxide (NO) and superoxide dismutase (SOD) activity in H2O2-induced HUVECs. At the same time, LEO treatment significantly promoted the phosphorylation level of angiogenic protein PI3K, Akt, and eNOS and the expression level of survival factor Bcl2 and decreased the expression level of death factor Bax and caspase3. In conclusion, our findings suggested that LEO can ameliorate the oxidative stress damage and insufficient angiogenesis of HUVECs induced by H2O2 through activating the PI3K/Akt-eNOS signaling pathway.

In vitro studies evaluating the efficacy of mouth rinses on Sars-Cov-2: A systematic review.

This systematic review aims to evaluate the evidence on the efficacy of mouth rinses on SARS-CoV-2 from in vitro studies. Five electronic databases were searched up to February 2021; no language or time restrictions were used. Two independent reviewers conducted both selection and data extraction processes. The toxicological data reliability assessment tool was used to evaluate the risk of bias. Starting from 239 articles, retrieved by the electronic search, only eight studies were included in our systematic review. Povidone Iodine (PVP-I) was effective in killing SARS-CoV-2, demonstrated higher virucidal activity than other commonly used active ingredients. Conflicting results were found about the effectiveness of Chlorhexidine (CHX) while hydrogen peroxide (H2O2) proved less effective than PVP-I. Other active ingredients, such as quaternary ammonium compounds and Ethanol (particularly when combined with essential oils), have also shown promising results in reducing viral load, with results comparable to PVP-I.