Hydrogen Peroxide as an Adjuvant Therapy for COVID-19: A Case Series of Patients and Caregivers in the Mexico City Metropolitan Area

Functionalized Copper Nanoparticles with Gold Nanoclusters: Part I. Highly Selective Electrosynthesis of Hydrogen Peroxide

Copper nanoparticles (CuNPs) and gold nanoclusters (AuNCs) show a high catalytic performance in generating hydrogen peroxide (H2O2), a property that can be exploited to kill disease-causing microbes and to carry carbon-free energy. Some combinations of NPs/NCs can generate synergistic effects to produce stronger antiseptics, such as H2O2 or other reactive oxygen species (ROS). Herein, we demonstrate a novel facile AuNC surface decoration method on the surfaces of CuNPs using galvanic displacement. The Cu-Au bimetallic NPs presented a high selective production of H2O2 via a two-electron (2e-) oxygen reduction reaction (ORR). Their physicochemical analyses were conducted by scanning electron microscopy (SEM), transmitting electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). With the optimized Cu-Au1.5NPs showing their particle sizes averaged in 53.8 nm, their electrochemical analysis indicated that the pristine AuNC structure exhibited the highest 2e- selectivity in ORR, the CuNPs presented the weakest 2e- selectivity, and the optimized Cu-Au1.5NPs exhibited a high 2e- selectivity of 95% for H2O2 production, along with excellent catalytic activity and durability. The optimized Cu-Au1.5NPs demonstrated a novel pathway to balance the cost and catalytic performance through the appropriate combination of metal NPs/NCs.

The effects of acute hydrogen peroxide exposure on respiratory cilia motility and viability

COVID-19 has seen the propagation of alternative remedies to treat respiratory disease, such as nebulization of hydrogen peroxide (H₂O₂). As H₂O₂ has known cytotoxicity, it was hypothesised that H₂O₂ inhalation would negatively impact respiratory cilia function. To test this hypothesis, mouse tracheal samples were incubated with different H₂O₂ concentrations (0.1-1%) then cilia motility, cilia generated flow, and cell death was assessed 0-120 min following H₂O₂ treatment. 0.1-0.2% H₂O₂ caused immediate depression of cilia motility and complete cessation of cilia generated flow. Higher H₂O₂ concentrations (≥0.5%) caused immediate complete cessation of cilia motility and cilia generated flow. Cilia motility and flow was restored 30 min after 0.1% H₂O₂ treatment. Cilia motility and flow remained depressed 120 min after 0.2-0.5% H₂O₂ treatment. No recovery was seen 120 min after treatment with ≥1% H₂O₂. Live/dead staining revealed that H₂O₂ treatment caused preferential cell death of ciliated respiratory epithelia over non-ciliated epithelia, with 1% H₂O₂ causing 35.3 ± 7.0% of the ciliated epithelia cells to die 120 min following initial treatment. This study shows that H₂O₂ treatment significantly impacts respiratory cilia motility and cilia generated flow, characterised by a significant impairment in cilia motility even at low concentrations, the complete cessation of cilia motility at higher doses, and a significant cytotoxic effect on ciliated respiratory epithelial cells by promoting cell death. While this data needs further study using in vivo models, it suggests that extreme care should be taken when considering treating respiratory diseases with nebulised H₂O₂.

Efectividad de enjuagues bucales contra virus de la familia coronavirus

La aparición del virus Sars-CoV-2 y la enfermedad Covid-19 han provocado un estado de emergencia en el sistema de salud. Teniendo en cuenta el potencial de la saliva como material contaminante, la práctica odontológica fue una de las áreas que se vio afectada debido al uso de instrumentos que pueden esparcir aerosoles y salpicaduras que contienen microorganismos hacia el medio ambiente. Por esta razón, conociendo su potencial en la inactivación de patógenos, se propuso la utilización de enjuagues bucales en la práctica clínica previo a la realización de procedimientos dentales, sin embargo la evidencia no es clara respecto a su efectividad. Objetivo. Establecer el estado de evidencia actual del efecto de los enjuagues bucales sobre los coronavirus que se encuentran en cavidad. Métodos. Se realizó una revisión sistemática siguiendo todos los parámetros descritos en las DirectricesPRISMA basada en información obtenida en los buscadores Science direct, Pubmed y Dentistry and Oral Science Source. Los criterios de selección incluyeron estudios in vivo e in vitro de texto completo que evidenciaron la efectividad del enjuague bucal contra coronavirus. Resultados. Se obtuvieron 90 artículos, de los cuales sólo 12 cumplían con los criterios de inclusión,8 in vitro y 4 in vivo, que fueron sometidos a la evaluación de calidad metodológica utilizando la lista de verificación de evaluación crítica del JBI.  Conclusiones. Los resultados sugieren que la povidona yodada es efectiva para la inactivación del virus Sars-coV-2 en todas sus concentraciones.

Performance of Pd catalyst supported on trimetallic nanohybrid Zr–Al–La in hydrogenation of ethylanthraquinone

In light of the recent COVID-19 pandemic, the demand for hydrogen peroxide has increased significantly due to its widespread use in disinfectant formulations. The present study aims to develop an efficient nanohybrid material as catalyst support for the successful hydrogenation of ethylanthraquinone for the production of hydrogen peroxide. Co-precipitation and wet impregnation methods were used to prepare nanohybrid Zr–Al–La supported Pd catalyst (Pd/Zr–Al–La). The high surface area (146.56 m2/g) of Zr–Al–La makes it suitable to use as support and causes to lower the mass transfer resistance and dispersion of active metal. XRF, BET, FTIR, and TGA were used to characterize the developed catalyst. The catalytic activity of the developed catalyst was studied using a high-pressure autoclave reactor to obtain a notable yield of H2O2 as 93.8% at 75 °C, 0.3 MPa, and 0.5 g of catalyst dose, a significant enhancement over the traditional Pd catalyst with Al2O3 support (63%) with the loss of active quinone compound. The mass transfer limitation of the reaction is high using only a Pd catalyst. The calculated mass transfer resistance of the reaction over Pd/Zr–Al–La catalyst was found to be moderate with a diffusion coefficient of the reactant (H2) as 0.0133 × 10−6 m2/s at 75 °C. It was also verified and confirmed with the Thiele modulus (calculated as 0.0314), no mass transfer resistance. The effectiveness factor (η s ) was found to be 1.0, indicating the negligible mass transfer resistance in the hydrogenation reaction using Pd/Zr–Al–La catalyst.

A Comparative Study on Alvogyl and a Mixture of Black Seed Oil and Powder for Alveolar Osteitis: A Randomized Double-Blind Controlled Clinical Trial

INTRODUCTION

Alveolar osteitis (AO) is the most common complication faced by exodontia patients and is usually seen 24-74 hours after tooth extraction, heralded by severe throbbing pain. Nigella sativa is commonly known as black seed known to have anti-inflammatory and antibacterial properties along with other reparative properties that enhance bone formation. This study aimed to evaluate and compare the effects of Alvogyl and a mixture of Nigella sativa powder and oil in the treatment of dry sockets.

MATERIALS AND METHODS

Sixty patients above the age of 18 and below 70 years, from both genders, who underwent extraction of teeth and were clinically diagnosed with a dry socket at the clinic of the College of Dentistry, Jouf University, Saudi Arabia, were included in this study. Pain scores were assessed after placement of the dressing at the following intervals: 5 minutes, 30 minutes, 60 minutes, 2^nd day, 4^th day, and 7^th day. Patients were randomly allocated to three groups, namely, Group 1 (Alvogyl), Group 2 (mixture of Nigella sativa's powder and oil), and Group 3 (control). Pain relief and healing of the socket were compared between the three groups. The collected data were subjected to statistical analysis through Spearman's correlation test, independent t-test, ANOVA, and post hoc test.

RESULTS

A mixture of Nigella sativa powder and oil showed a statistically significant difference in relieving pain compared to the Alvogyl group. A mixture of Nigella sativa's powder and oil required fewer dressings when compared to the Alvogyl group.

CONCLUSION

A mixture of Nigella sativa powder and oil is the more efficacious dressing material for the management of dry sockets compared to Alvogyl. It provides immediate and complete pain relief and fewer numbers of repeated visits.

Public Buses Decontamination by Automated Hydrogen Peroxide Aerosolization System

BACKGROUND: Public transportation has been linked to an increase in the risk of coronavirus disease 2019 transmission. The effective decontamination system using aerosolized hydrogen peroxide can mitigate the transmission risk from using public transportation. AIM: The aim of this study was to develop and validate an effective decontamination system for public transport. METHODS: The experimental research was performed in 13 inter-city public buses. The aerosol generator with ultrasonic atomizer was used in the experiment. The validation process for disinfection was conducted using both a chemical indicator (CI) and spore discs biological indicator (inoculated with 106 Geobacillus stearothermophilus enclosed in glassine envelopes). The CIs and biological indicators were marked by number and placed in nine locations on each bus. The decontamination cycle was developed by analyzed of various aerosolized and decomposition period. Both concentrations of hydrogen peroxide, 5% and 7%, were used for comparison. RESULTS: In an aerosolized period, both concentrations of hydrogen peroxide at 30 min were effective for sporicidal 6-log reductions. The decontamination cycle totaled 100 min, based on a 70 min average decomposition time. CONCLUSIONS: The automated hydrogen peroxide aerosolized system is a highly effective and safe method of decontaminating public buses.