Development of an Ultraviolet-C Irradiation Room in a Public Portuguese Hospital for Safe Re-Utilization of Personal Protective Respirators

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.

Zirconia Dental Implants Surface Electric Stimulation Impact on Staphylococcus aureus

Tooth loss during the lifetime of an individual is common. A strategy to treat partial or complete edentulous patients is the placement of dental implants. However, dental implants are subject to bacterial colonization and biofilm formation, which cause an infection named peri-implantitis. The existing long-term treatments for peri-implantitis are generally inefficient. Thus, an electrical circuit was produced with zirconia (Zr) samples using a hot-pressing technique to impregnate silver (Ag) through channels and holes to create a path by LASER texturing. The obtained specimens were characterized according to vitro cytotoxicity, to ensure ZrAg non-toxicity. Furthermore, samples were inoculated with Staphylococcus aureus using 6.5 mA of alternating current (AC). The current was delivered using a potentiostat and the influence on the bacterial concentration was assessed. Using AC, the specimens displayed no bacterial adhesion (Log 7 reduction). The in vitro results presented in this study suggest that this kind of treatment can be an alternative and promising strategy to treat and overcome bacterial adhesion around dental implants that can evolve to biofilm.

Enhancing Functionalization of Health Care Textiles with Gold Nanoparticle-Loaded Hydroxyapatite Composites

Hospitals and nursing home wards are areas prone to the propagation of infections and are of particular concern regarding the spreading of dangerous viruses and multidrug-resistant bacteria (MDRB). MDRB infections comprise approximately 20% of cases in hospitals and nursing homes. Healthcare textiles, such as blankets, are ubiquitous in hospitals and nursing home wards and may be easily shared between patients/users without an adequate pre-cleaning process. Therefore, functionalizing these textiles with antimicrobial properties may considerably reduce the microbial load and prevent the propagation of infections, including MDRB. Blankets are mainly comprised of knitted cotton (CO), polyester (PES), and cotton-polyester (CO-PES). These fabrics were functionalized with novel gold-hydroxyapatite nanoparticles (AuNPs-HAp) that possess antimicrobial properties, due to the presence of the AuNPs' amine and carboxyl groups, and low propensity to display toxicity. For optimal functionalization of the knitted fabrics, two pre-treatments, four different surfactants, and two incorporation processes were evaluated. Furthermore, exhaustion parameters (time and temperature) were subjected to a design of experiments (DoE) optimization. The concentration of AuNPs-HAp in the fabrics and their washing fastness were critical factors assessed through color difference (ΔE). The best performing knitted fabric was half bleached CO, functionalized using a surfactant combination of Imerol^® Jet-B (surfactant A) and Luprintol^® Emulsifier PE New (surfactant D) through exhaustion at 70 °C for 10 min. This knitted CO displayed antibacterial properties even after 20 washing cycles, showing its potential to be used in comfort textiles within healthcare environments.

PMMA Microcapsules for the Inactivation of SARS-CoV-2

Surface disinfection currently plays a decisive role in the epidemiological situation caused by the SARS-CoV-2 coronavirus. However, most disinfection products available on the market have a high evaporation rate and only an immediate action and not continuous, creating the need for a high frequency of disinfection. To overcome this limitation, in the present work, poly(methyl methacrylate) (PMMA) microcapsules were developed with an active agent (hydrogen peroxide) encapsulated, which has the ability to inactivate/neutralize the SARS-CoV-2 virus. PMMA-H₂O₂ microcapsules have a spherical shape and a smooth structure with low porosity and were successfully attached to nonwoven fabrics, as observed from scanning electron microscopy. The thermogravimetric analysis shows that PMMA-H₂O₂ microcapsules have high thermal stability and can increase the stability of H₂O₂. Nonfabric substrates functionalized with PMMA-H₂O₂ microcapsules were tested by a highly sensitive and specific reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR)-based method to evaluate antiviral activity through the degradation of SARS-CoV-2 deoxyribonucleic acids. The highest percentage of viral nucleic acid elimination was obtained when exposing the viral sample for 1 h to PMMA-H₂O₂ microcapsules, resulting in an elimination of >97% of the coronavirus. In addition, the microcapsules are stable over a period of three weeks and retain the ability to eliminate SARS-CoV-2. Hence, it is demonstrated that this microcapsule system is efficient for SARS-CoV-2 elimination and inherent surface disinfection.