Methylene blue applied to N95 respirators and medical masks for SARS-CoV-2 decontamination: What is the likelihood of inhaling methylene blue?

Piezoelectric nanogenerators from sustainable biowaste source: Power harvesting and respiratory monitoring with electrospun crab shell powder-poly(vinylidene fluoride) composite nanofibers

Wearable piezoelectric nanogenerators (PENGs) are increasingly significant in healthcare and energy harvesting applications due to their ability to convert mechanical energy into electrical signals. In this study, we developed PENGs by incorporating crab shell powder (CS-NFs) into electrospun polyvinylidene fluoride (PVDF) nanofibers to enhance their piezoelectric properties. The PVDF-CS-NFs (PC-NFs) composites were evaluated for structural, thermal, and piezoelectric performance. The 1.5 wt% CS-NFs composite exhibited a notable improvement, with a maximum output voltage of 19 V under mechanical deformation, significantly higher than pristine PVDF NFs. Furthermore, the device demonstrated excellent sensitivity in real-time respiratory monitoring when applied to various body locations, including the chest, throat, and mask. Additionally, the PC-NFs-based PENGs were capable of charging a 2.2 µF capacitor to 2 V within 180 s and powering 56 LEDs. These results underscore the potential of using sustainable crab shell waste in biocompatible, eco-friendly piezoelectric devices for wearable sensors and energy harvesting applications.

Integrity and filtration efficiency of decontaminated N95/PFF2 masks to protect health care professionals against COVID-19: A systematic literature review and meta-analysis

BACKGROUND

To evaluate the evidence related to maintaining the integrity and filtration efficiency of N95 and/or PFF2 respirators after decontamination in health care professionals' protection against COVID-19.

METHODS

Systematic review, developed based on the guidelines from Joanna Briggs Institute for syntheses focusing on effectiveness evidence. The protocol was registered on the International Prospective Register of Ongoing Systematic Reviews platform, under the number CRD42022354256. This study report was developed in accordance with the guidelines recommended by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Publications between January 2020 and August 2022 were selected of Embase, Medline, CINAHL, Web of Science, Cochrane, SciELO and Virtual Health Library databases. Joanna Briggs critical appraisal tool for nonrandomized experimental tests was used to evaluate the evidence quality.

RESULTS

Seven articles were included in the data extraction and critical evaluation, and 3 in the meta-analysis. Four studies evaluated the integrity by visual inspection and 2 by electron microscopy. There was no association between the number of cycles increase and the reduction in filtration in up to 10 cycles. None study was considered of high methodological quality.

CONCLUSIONS

There is some evidence that integrity and filtration capacity were maintained after decontamination of N95/PFF2 respirators to prevent COVID-19.

aPDI meets PPE: photochemical decontamination in healthcare using methylene blue-where are we now, where will we go?

Personal protective equipment (PPE) reuse, first recommended in the context of the SARS-CoV-2 pandemic, can mitigate shortages in crisis situations and can greatly reduce the environmental impact of typically single-use PPE. Prior to safe reuse, PPE must be sanitized and contaminating pathogens-in current circumstances viruses in particular-must be inactivated. However, many established decontamination procedures are not equitable and remain unavailable in low-resource settings. In mid-2020, an interdisciplinary consortium of researchers first studied the potential of implementing cheap and easy-to-use antimicrobial photodynamic inactivation (aPDI) using methylene blue as photosensitizer to decontaminate face masks and filtering facepiece respirators. In this perspective piece, we describe the development of this novel method, discuss recent advances, and offer insights into how equitable PPE decontamination via methylene blue-based aPDI may be integrated into circular economy policies in the healthcare sector.

Application of methylene blue for the prevention and treatment of COVID-19: A narrative review

The newest virus from the SARS family of viruses called acute syndrome-coronavirus-2 (SARS-CoV-2), which causes COVID-19 disease, was identified in China at the end of 2019. In March 2020, after it spread to 29 additional countries, it was declared a pandemic by the World Health Organization (WHO). SARS-CoV-2 infection mainly starts through the respiratory tract and causes a wide spectrum of symptoms from asymptomatic infections to acute respiratory distress syndrome with multi-organ failure and vasoplegic shock. Among the many immunomodulatory and antiviral drugs that have been studied for the treatment of COVID-19, methylene blue (MB) may play an influential role. This article reviews the history of MB applications, the antiviral effects of MB against SARS-CoV-2, and the results of in vivo and in vitro studies of the use of MB in COVID-19. Based on studies, MB can simultaneously affect most of the host's harmful responses caused by SARS-CoV-2 infection due to its multiple properties, including anti-hypoxemia, anti-oxidant, immune system modulator, and antiviral. The use of MB is associated with a reduction in the possibility of getting infection, and mortality, and can be used as a safe, effective, cheap, and available treatment option with minimal side effects for the clinical management of COVID-19.