The COVID-19 pandemic has demonstrated the real need for mechanisms to control the spread of airborne respiratory pathogens. Thus, preventing the spread of disease from pathogens has come to the ...forefront of the public consciousness. This has brought an increasing demand for novel technologies to prioritise clean air. In this study we report on the efficacy of novel biocide treated filters and their antimicrobial activity against bacteria, fungi and viruses. The antimicrobial filters reported here are shown to kill pathogens, such as Candida albicans, Escherichia coli and MRSA in under 15 min and to destroy SARS-CoV-2 viral particles in under 30 s following contact with the filter. Through air flow rate testing, light microscopy and SEM, the filters are shown to maintain their structure and filtration function. Further to this, the filters are shown to be extremely durable and to maintain antimicrobial activity throughout the operational lifetime of the product. Lastly, the filters have been tested in field trials onboard the UK rail network, showing excellent efficacy in reducing the burden of microbial species colonising the air conditioning system.
There is an increasing focus in healthcare environments on combatting antimicrobial resistant infections. While bacterial infections are well reported, infections caused by fungi receive less ...attention, yet have a broad impact on society and can be deadly. Fungi are eukaryotes with considerable shared biology with humans, therefore limited technologies exist to combat fungal infections and hospital infrastructure is rarely designed for reducing microbial load. In this study, a novel antimicrobial surface (AMS) that is modified with the broad‐spectrum biocide chlorhexidine is reported. The surfaces are shown to kill the opportunistic fungal pathogens Candida albicans and Cryptococcus neoformans very rapidly (<15 min) and are significantly more effective than current technologies available on the commercial market, such as silver and copper.
Transmission of disease is a global problem. In the current climate, there is a significant focus on airborne transmission. However, in many infections, surfaces play a key role in transmission. The present study demonstrates the efficacy of an antimicrobial surface technology in killing opportunistic fungal pathogens.
Nanomaterials of zinc oxide (ZnO) exhibit antibacterial activities under ambient illumination that result in cell membrane permeability and disorganization, representing an important opportunity for ...health-related applications. However, the development of antibiofouling surfaces incorporating ZnO nanomaterials has remained limited. In this work, we fabricate superhydrophobic surfaces based on ZnO nanopillars. Water droplets on these superhydrophobic surfaces exhibit small contact angle hysteresis (within 2–3°) and a minimal tilting angle of 1°. Further, falling droplets bounce off when impacting the superhydrophobic ZnO surfaces with a range of Weber numbers (8–46), demonstrating that the surface facilitates a robust Cassie–Baxter wetting state. In addition, the antibiofouling efficacy of the surfaces has been established against model pathogenic Gram-positive bacteria Staphylococcus aureus (S. aureus) and Gram-negative bacteria Escherichia coli (E. coli). No viable colonies of E. coli were recoverable on the superhydrophobic surfaces of ZnO nanopillars incubated with cultured bacterial solutions for 18 h. Further, our tests demonstrate a substantial reduction in the quantity of S. aureus that attached to the superhydrophobic ZnO nanopillars. Thus, the superhydrophobic ZnO surfaces offer a viable design of antibiofouling materials that do not require additional UV illumination or antimicrobial agents.
The development of a polyarginine cell-penetrating peptide (CPP) could enable the treatment of age-related macular degeneration, with drugs like bevacizumab, to be administered using eye drops ...instead of intravitreal injections. Topical formulations have a vast potential impact on healthcare by increasing patient compliance while reducing the financial burden. However, as the ocular preparations may contain several doses, it is essential to understand the stability of the bevacizumab+CPP conjugate produced.
In this work, we examine the stability of a bevacizumab solution with and without cell-penetrating peptide using dynamic light scattering and circular dichroism to assess the physical stability. We use HPLC to assess the chemical stability and ELISA to assess its biological activity. We also examine the potential of the CPP to be used as an antimicrobial agent in place of preservatives in the eye drop.
The structural stability of bevacizumab with and without the CPP was found not to be affected by temperature: samples stored at either 20°C or 4°C were identical in behavior. However, physical instability was observed after five weeks, leading to aggregation and precipitation. Further investigation revealed that the addition of the polypeptide led to increased aggregation, as revealed through dynamic light scattering and concentration analysis of the peptide through HPLC. Complexing the bevacizumab with CPP had no effect on biological stability or degradation.
Our findings suggest that the shelf life of CPP+bevacizumab complexes is at least 38 days from its initial formulation. Currently, the mechanism for aggregation is not fully understood but does not appear to occur through chemical degradation.
Despite bacterial biofilms representing a common form of infection, notably on medical devices post implantation, their detection and characterisation with existing methods is not sufficient to ...inform clinicians about biofilm presence or treatment response in affected patients. This study reports the development and use of a combined hyperspectral imaging (HSI) and electrochemical platform to monitor biofilm formation optically and electrochemically. Firstly, production of pyocyanin, a common pigmented and redox active secondary metabolite produced by P. aeruginosa , is monitored by combined HSI and square-wave voltammetry. Secondly, P. aeruginosa biofilm formation is characterised directly using electrochemical impedance spectroscopy. This suite of optical and electrochemical measurements allows for combined monitoring of secondary metabolite/virulence factor production along with direct monitoring of biofilm formation on the sensor surface. Crucially, the easy to deploy and low-cost nature of the selected sensing technologies means the approach can be developed for enhanced study of biofilms and/or at the point of care.
The opportunistic pathogen,
Pseudomonas aeruginosa
, is infamous for its ability to rapidly form biofilms (<24 h) in inhospitable environments and the development of antimicrobial resistance (AMR). ...It has been seen to have resistance to nearly all known antibiotics, including last-line antibiotics colistin and carbapenems. AMR is currently considered one of the biggest threats to human health, causing 700,000 deaths annually, expected to rise to 10 million deaths per year by 2050.
P. aeruginosa
, alongside other opportunistic pathogens, has been implicated in infections following various surgical procedures. Such infections compromise patient recovery and, when a medical implant is present a biofilm can develop that will ultimately require a complex revision surgery to remove the infection.
In this study, impedance spectroscopy and differential pulse voltammetry were carried out in parallel to measure electrochemical and impedance properties of bacteria, allowing for identification and quantification of pyoverdine and pyocyanin; bacterial metabolites. Three
Pseudomonas
spp. (
P. aeruginosa
,
P. fluorescens
and
P. putida
) were assayed in liquid culture at OD600. The sensor was standardised with pyoverdine and pyocyanin, with an electrochemical reading taken every 30 minutes up to 4 hours. This assay was repeated with
Pseudomonas
spp. growing in biofilms in LB broth, with a screen-printed electrode as the solid surface. Readings were then used to correlate metabolite production to biofilm production in each
Pseudomonas
sp. Pyoverdine correlated with biofilm formation for all three assayed
Pseudomonas
, with variation in the quantity of metabolite produced between species. This allows the two metabolites to be used as indicators of biofilm mass on devices and surfaces.
Despite increased sterilisation and education campaigns, hospital acquired infections have not been eradicated. Bacterial colonisation of frequent touch surfaces is key in the transmission of ...infection. Most current technologies cannot provide a material which can rapidly kill bacteria. Here we report a novel surface technology, which uses synthetic mimetics of human defensin proteins on a surface. The surface shows excellent antibacterial efficacy against Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus, Pseudomonas aeruginosa and Escherichia coli. Both microbiology laboratory tests and trials in hospital settings of this new antimicrobial material (AMS) showed >99% efficacy over a year in situ. It maintains its efficacy through accelerated ageing tests and has shown to kill bacteria far more rapidly (45 min) than the commercially available technologies (24 h).
•It demonstrates a novel coating method for applying organic antibacterial actives to the surface of steel substrates (AMS).•The AMS system shows excellent antibacterial efficacy against a range of pathogens including both Gram positive and Gram negative.•The AMS shows efficacy in clinical trials over 1 year.
The development of a polyarginine cell-penetrating peptide (CPP) could enable the treatment of age-related macular degeneration, with drugs like bevacizumab, to be administered using eye drops ...instead of intravitreal injections. Topical formulations have a vast potential impact on healthcare by increasing patient compliance while reducing the financial burden. However, as the ocular preparations may contain several doses, it is essential to understand the stability of the bevacizumab+CPP conjugate produced.
In this work, we examine the stability of a bevacizumab solution with and without cell-penetrating peptide using dynamic light scattering and circular dichroism to assess the physical stability. We use HPLC to assess the chemical stability and ELISA to assess its biological activity. We also examine the potential of the CPP to be used as an antimicrobial agent in place of preservatives in the eye drop.
The structural stability of bevacizumab with and without the CPP was found not to be affected by temperature: samples stored at either 20°C or 4°C were identical in behavior. However, physical instability was observed after five weeks, leading to aggregation and precipitation. Further investigation revealed that the addition of the polypeptide led to increased aggregation, as revealed through dynamic light scattering and concentration analysis of the peptide through HPLC. Complexing the bevacizumab with CPP had no effect on biological stability or degradation.
Our findings suggest that the shelf life of CPP+bevacizumab complexes is at least 38 days from its initial formulation. Currently, the mechanism for aggregation is not fully understood but does not appear to occur through chemical degradation.
Objective: Research among young adults (YA), in samples of majority White college students, indicates links between posting about alcohol on social media and self-reported drinking behavior. We ...sought to extend this work by examining unique associations between public versus private posting about alcohol and the high-risk outcome of alcohol-related blackouts among a sample of racially/ethnically diverse YA not in 4-year college. Method: A sample of 499 participants (ages 18–29; 52.5% female; 37.5% Black/African American, 26.9% White, 25.3% Hispanic/Latinx) completed an online survey about social media use and drinking behavior. Results: Across three platforms (Instagram, TikTok, Twitter now known as “X”), public posting on Instagram was most common. Adjusting for covariates, a higher frequency of private posting about alcohol was associated with a higher frequency of past-month blackouts. Tests of simple effects of posting on blackouts within racial/ethnic subgroups indicated that private posting about alcohol was significantly associated with past-month blackouts only among those who most strongly identified as Black/African American or White but not among those who most strongly identified as Hispanic/Latinx. Further, public posting was significantly associated with past-month blackouts, though the association was specific to White participants. Conclusions: Whether posting about alcohol may be useful in identifying risky drinking behavior may depend on racial/ethnic identification as well as whether private or public posting is being considered. Results have implications for eventual online interventions, which can identify individuals potentially at risk for hazardous drinking based on their social media posting behavior. (PsycInfo Database Record (c) 2024 APA, all rights reserved) (Source: journal abstract)
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