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1.
bioRxiv ; 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38562889

RESUMO

Wound infections, exacerbated by the prevalence of antibiotic-resistant bacterial pathogens, necessitate innovative antimicrobial approaches. Polymicrobial infections, often involving Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), present formidable challenges due to biofilm formation and antibiotic resistance. Hypochlorous acid (HOCl), a potent antimicrobial agent produced naturally by the immune system, holds promise as an alternative therapy. An electrochemical bandage (e-bandage) that generates HOCl in situ was evaluated for treatment of murine wound biofilm infections containing both MRSA and P. aeruginosa with "difficult-to-treat" resistance. Previously, the HOCl-producing e-bandage was shown to reduce wound biofilms containing P. aeruginosa alone. Compared to non-polarized e-bandage (no HOCl production) and Tegaderm only controls, the polarized e-bandages reduced bacterial loads in wounds infected with MRSA plus P. aeruginosa (MRSA: vs Tegaderm only - 1.4 log10 CFU/g, p = 0.0015, vs. non-polarized - 1.1 log10 CFU/g, p = 0.026. P. aeruginosa: vs Tegaderm only - 1.6 log10 CFU/g, p = 0.0015, vs non-polarized - 1.6 log10 CFU/g, p = 0.0032), and MRSA alone (vs Tegaderm only - 1.3 log10 CFU/g, p = 0.0048, vs. non-polarized - 1.1 log10 CFU/g, p = 0.0048), without compromising wound healing or causing tissue toxicity. Addition of systemic antibiotics did not enhance the antimicrobial efficacy of e-bandages, highlighting their potential as standalone therapies. This study provides additional evidence for the HOCl-producing e-bandage as a novel antimicrobial strategy for managing wound infections, including in the context of antibiotic resistance and polymicrobial infections.

2.
bioRxiv ; 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38585771

RESUMO

Electrochemical bandages (e-bandages) can be applied to biofilm-infected wounds to generate reactive oxygen species, such as hypochlorous acid (HOCl) or hydrogen peroxide (H 2 O 2 ). The e-bandage-generated HOCl or H 2 O 2 kills biofilms in vitro and in infected wounds on mice. The HOCl-generating e-bandage is more active against biofilms in vitro , although this distinction is less apparent in vivo . The H 2 O 2 -generating e-bandage, more than the HOCl-generating e-bandage, is associated with improved healing of infected wounds. A strategy in which H 2 O 2 and HOCl are generated alternately-for dual action-was explored. The goal was to develop a programmable multimodal wearable potentiostat (PMWP) that could be programmed to generate HOCl or H 2 O 2 , as needed. An ultralow-power microcontroller unit managed operation of the PMWP. The system was operated with a 260-mAh capacity coin battery and weighed 4.6 grams, making it suitable for small animal experiments or human use. The overall cost of a single wearable potentiostat was $6.50 (USD). The device was verified using established electrochemical systems and functioned comparably to a commercial potentiostat. To determine antimicrobial effectiveness, PMWP-controlled e-bandages were tested against clinical isolates of four prevalent chronic wound bacterial pathogens, methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Acinetobacter baumannii , and Enterococcus faecium , and one fungal pathogen of emerging concern, Candida auris . PMWP-controlled e-bandages exhibited broad-spectrum activity against biofilms of all study isolates tested when programmed to deliver HOCl followed by H 2 O 2 . These results show that the PMWP operates effectively and is suitable for animal testing.

3.
Antimicrob Agents Chemother ; 68(2): e0121623, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38214514

RESUMO

The growing threat of antibiotic-resistant bacterial pathogens necessitates the development of alternative antimicrobial approaches. This is particularly true for chronic wound infections, which commonly harbor biofilm-dwelling bacteria. A novel electrochemical bandage (e-bandage) delivering low-levels of hypochlorous acid (HOCl) was evaluated against Pseudomonas aeruginosa murine wound biofilms. 5 mm skin wounds were created on the dorsum of mice and infected with 106 colony-forming units (CFU) of P. aeruginosa. Biofilms were formed over 2 days, after which e-bandages were placed on the wound beds and covered with Tegaderm. Mice were administered Tegaderm-only (control), non-polarized e-bandage (no HOCl production), or polarized e-bandage (using an HOCl-producing potentiostat), with or without systemic amikacin. Purulence and wound areas were measured before and after treatment. After 48 hours, wounds were harvested for bacterial quantification. Forty-eight hours of polarized e-bandage treatment resulted in mean biofilm reductions of 1.4 log10 CFUs/g (P = 0.0107) vs non-polarized controls and 2.2 log10 CFU/g (P = 0.004) vs Tegaderm-only controls. Amikacin improved CFU reduction in Tegaderm-only (P = 0.0045) and non-polarized control groups (P = 0.0312) but not in the polarized group (P = 0.3876). Compared to the Tegaderm-only group, there was less purulence in the polarized group (P = 0.009). Wound closure was neither impeded nor improved by either polarized or non-polarized e-bandage treatment. Concurrent amikacin did not impact wound closure or purulence. In conclusion, an HOCl-producing e-bandage reduced P. aeruginosa in wound biofilms with no impairment in wound healing, representing a promising antibiotic-free approach for addressing wound infection.


Assuntos
Infecções por Pseudomonas , Infecção dos Ferimentos , Animais , Camundongos , Pseudomonas aeruginosa , Ácido Hipocloroso , Amicacina , Infecções por Pseudomonas/microbiologia , Infecção dos Ferimentos/microbiologia , Bandagens , Antibacterianos , Biofilmes
4.
bioRxiv ; 2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37790575

RESUMO

A novel electrochemical bandage (e-bandage) delivering low-level hypochlorous acid (HOCl) was evaluated against Pseudomonas aeruginosa murine wound biofilms. 5 mm skin wounds were created on the dorsum of Swiss-Webster mice and infected with 10 6 colony forming units (CFU) of P. aeruginosa . Biofilms were formed over two days, after which e-bandages were placed on the wound beds and covered with Tegaderm™. Mice were administered Tegaderm-only (control), non-polarized e-bandage (no HOCl production), or polarized e-bandage (using an HOCl-producing potentiostat), with or without concurrently administered systemic amikacin. Purulence and wound areas were measured before and after treatment. After 48 hours, animals were sacrificed, and wounds were harvested for bacterial quantification. Forty-eight hours of polarized e-bandage treatment resulted in mean biofilm reductions of 1.4 log 10 CFUs/g (9.0 vs 7.6 log 10 ; p = 0.0107) vs non-polarized controls, and 2.2 log 10 CFU/g (9.8 vs 7.6 log 10 ; p = 0.004) vs Tegaderm only controls. Systemic amikacin improved CFU reduction in Tegaderm-only (p = 0.0045) and non-polarized control groups (p = 0.0312), but not in the polarized group (p = 0.3876). Compared to the Tegaderm only group, there was more purulence reduction in the polarized group (p = 0.009), but not in the non-polarized group (p = 0.064). Wound closure was not impeded or improved by either polarized or non-polarized e-bandage treatment. Concurrent amikacin did not impact wound closure or purulence. In conclusion, an HOCl-producing e-bandage reduced P. aeruginosa in wound biofilms with no impairment in wound healing, representing a promising antibiotic-free approach for addressing wound infections.

5.
Angew Chem Int Ed Engl ; 61(40): e202207175, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-35876840

RESUMO

2',3'-cGAMP is a cyclic A- and G-containing dinucleotide second messenger, which is formed upon cellular recognition of foreign cytosolic DNA as part of the innate immune response. The molecule binds to the adaptor protein STING, which induces an immune response characterized by the production of type I interferons and cytokines. The development of STING-binding molecules with both agonistic as well as antagonistic properties is currently of tremendous interest to induce or enhance antitumor or antiviral immunity on the one hand, or to treat autoimmune diseases on the other hand. To escape the host innate immune recognition, some viruses encode poxin endonucleases that cleave 2',3'-cGAMP. Here we report that dideoxy-2',3'-cGAMP (1) and analogs thereof, which lack the secondary ribose-OH groups, form a group of poxin-stable STING agonists. Despite their reduced affinity to STING, particularly the compound constructed from two A nucleosides, dideoxy-2',3'-cAAMP (2), features an unusually high antitumor response in mice.


Assuntos
Interferon Tipo I , Proteínas de Membrana/genética , Nucleosídeos , Animais , Antivirais , Citocinas , DNA , Endonucleases , Imunidade Inata , Proteínas de Membrana/metabolismo , Camundongos , Nucleotídeos Cíclicos , Nucleotidiltransferases/metabolismo , Ribose
6.
Chembiochem ; 23(8): e202200005, 2022 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-35189023

RESUMO

The cGAS-STING pathway is known for its role in sensing cytosolic DNA introduced by a viral infection, bacterial invasion or tumorigenesis. Free DNA is recognized by the cyclic GMP-AMP synthase (cGAS) catalyzing the production of 2',3'-cyclic guanosine monophosphate-adenosine monophosphate (2',3'-cGAMP) in mammals. This cyclic dinucleotide acts as a second messenger, activating the stimulator of interferon genes (STING) that finally triggers the transcription of interferon genes and inflammatory cytokines. Due to the therapeutic potential of this pathway, both the production and the detection of cGAMP via fluorescent moieties for assay development is of great importance. Here, we introduce the paralleled synthetic access to the intrinsically fluorescent, cyclic dinucleotides 2'3'-cth GAMP and 3'3'-cth GAMP based on phosphoramidite and phosphate chemistry, adaptable for large scale synthesis. We examine their binding properties to murine and human STING and confirm biological activity including interferon induction by 2'3'-cth GAMP in THP-1 monocytes. Two-photon imaging revealed successful cellular uptake of 2'3'-cth GAMP in THP-1 cells.


Assuntos
Proteínas de Membrana , Nucleotidiltransferases , Animais , DNA/metabolismo , Fosfatos de Dinucleosídeos , Humanos , Interferons , Mamíferos/genética , Mamíferos/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Nucleotidiltransferases/metabolismo , Sistemas do Segundo Mensageiro
7.
Nat Commun ; 12(1): 4100, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34215750

RESUMO

Tet3 is the main α-ketoglutarate (αKG)-dependent dioxygenase in neurons that converts 5-methyl-dC into 5-hydroxymethyl-dC and further on to 5-formyl- and 5-carboxy-dC. Neurons possess high levels of 5-hydroxymethyl-dC that further increase during neural activity to establish transcriptional plasticity required for learning and memory functions. How αKG, which is mainly generated in mitochondria as an intermediate of the tricarboxylic acid cycle, is made available in the nucleus has remained an unresolved question in the connection between metabolism and epigenetics. We show that in neurons the mitochondrial enzyme glutamate dehydrogenase, which converts glutamate into αKG in an NAD+-dependent manner, is redirected to the nucleus by the αKG-consumer protein Tet3, suggesting on-site production of αKG. Further, glutamate dehydrogenase has a stimulatory effect on Tet3 demethylation activity in neurons, and neuronal activation increases the levels of αKG. Overall, the glutamate dehydrogenase-Tet3 interaction might have a role in epigenetic changes during neural plasticity.


Assuntos
Núcleo Celular/enzimologia , Núcleo Celular/metabolismo , Dioxigenases/metabolismo , Glutamato Desidrogenase/metabolismo , Ácidos Cetoglutáricos/metabolismo , Neurônios/metabolismo , Animais , Encéfalo/metabolismo , Ciclo do Ácido Cítrico , Dioxigenases/genética , Epigenômica , Expressão Gênica , Glutamato Desidrogenase/genética , Ácido Glutâmico/metabolismo , Células HEK293 , Humanos , Complexo Cetoglutarato Desidrogenase/metabolismo , Metabolômica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Plasticidade Neuronal
8.
Int J Clin Pract ; 75(4): e13891, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33278857

RESUMO

OBJECTIVE: In this study, we aim to investigate the thoughts and attitudes of individuals towards the future COVID-19 vaccine. METHODS: This descriptive study was carried out on the web between 10/06/2020 and 10/07/2020. The sample constitutes all individuals above 18 years of age using social media and smartphone. The e-survey form was shared by the researchers via the web for a month, and those who completed the survey were included in the study and formed the sample of the research. RESULTS: Seven-hundred and fifty-nine people participated. 49.7% of the participants stated to be vaccinated; 38.4% of them stated to be vaccinated their children against COVID-19; if the vaccine for COVID-19 is developed. The request for the COVID-19 vaccine had relationship with gender, occupation, health insurance, anxiety level, having children and willing to get vaccinated for their children. "Afraid of the side effects of vaccine", "don't think it can be reliable as it will be a new vaccine" and "COVID-19 infection is a biological weapon and the vaccine will serve those who produce this virus" were the most common reasons for rejection of vaccine. CONCLUSION: In our study, afraid of the side effects of vaccine and not thinking it can be reliable as it will be a new vaccine are the most reasons of indecision and rejection about COVID 19 vaccine. In order for the future COVID 19 vaccination campaign to not fail, media, politicians and healthcare professionals should closely follow the vaccination development processes, inform the public transparently and consider public's concerns.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Opinião Pública , Adulto , COVID-19/prevenção & controle , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde , Humanos , Masculino , SARS-CoV-2 , Adulto Jovem
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