scholarly journals Development of a High-Throughput ex-Vivo Burn Wound Model Using Porcine Skin, and Its Application to Evaluate New Approaches to Control Wound Infection

2018 ◽  
Vol 8 ◽  
Author(s):  
Diana R. Alves ◽  
Simon P. Booth ◽  
Paola Scavone ◽  
Pascale Schellenberger ◽  
Jonathan Salvage ◽  
...  
Keyword(s):  
Wound Infection ◽  
High Throughput ◽  
Ex Vivo ◽  
Porcine Skin ◽  
Burn Wound ◽  
New Approaches ◽  
Wound Model

scholarly journals Active neutrophil responses counteract Candida albicans burn wound infection of ex vivo human skin explants

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Christin von Müller ◽  
Fionnuala Bulman ◽  
Lysett Wagner ◽  
Daniel Rosenberger ◽  
Alessandra Marolda ◽  
...  
Keyword(s):  
Human Skin ◽  
Ex Vivo ◽  
Burn Wound ◽  
Local Immunity ◽  
Fungal Virulence ◽  
Opportunistic Fungi ◽  
Burn Wounds ◽  
Wound Model ◽  
Skin Explants ◽  
Bacteria And Fungi

AbstractBurn wounds are highly susceptible sites for colonization and infection by bacteria and fungi. Large wound surface, impaired local immunity, and broad-spectrum antibiotic therapy support growth of opportunistic fungi such as Candida albicans, which may lead to invasive candidiasis. Currently, it remains unknown whether depressed host defenses or fungal virulence drive the progression of burn wound candidiasis. Here we established an ex vivo burn wound model, where wounds were inflicted by applying preheated soldering iron to human skin explants, resulting in highly reproducible deep second-degree burn wounds. Eschar removal by debridement allowed for deeper C. albicans penetration into the burned tissue associated with prominent filamentation. Active migration of resident tissue neutrophils towards the damaged tissue and release of pro-inflammatory cytokine IL-1β accompanied the burn. The neutrophil recruitment was further increased upon supplementation of the model with fresh immune cells. Wound area and depth decreased over time, indicating healing of the damaged tissue. Importantly, prominent neutrophil presence at the infected site correlated to the limited penetration of C. albicans into the burned tissue. Altogether, we established a reproducible burn wound model of candidiasis using ex vivo human skin explants, where immune responses actively control the progression of infection and promote tissue healing.

scholarly journals Laboratory study to investigate the sensitivity and specificity of a diagnostic dressing to detect burn wound infection

2021 ◽  
Author(s):  
Naing T Thet ◽  
Andrew Toby Jenkins ◽  
June D Mercer-Chalmers ◽  
Karen Coy ◽  
Simon Booth ◽  
...  
Keyword(s):  
Wound Infection ◽  
Wound Dressing ◽  
Clinical Symptoms ◽  
Ex Vivo ◽  
Clinical Decision ◽  
Wound Dressings ◽  
Point Estimate ◽  
Reference Standard ◽  
Burn Wound ◽  
Future Utility

Burn Wound Infection (BWI) is difficult to define and detect before it manifests with clear clinical symptoms. In this paper, an ex vivo study of a prototype BWI detecting wound dressing is reported. Consenting patients with burns were recruited from four burns services in the United Kingdom, their burn infection state recorded at time of recruitment and retrospectively following treatment. Their wound dressings were used as a source of inoculating bacteria to create an ex vivo biofilm model in the laboratory with reasonable fidelity to the original microbial state of their wound. The prototype infection detecting wound dressing, which responds to cytolytic toxins secreted by bacteria, was placed on the ex vivo biofilm and the response of the dressing correlated with the clinical decision on the patient's wound infection state. The study illustrated a number of broader issues with clinical BWI diagnosis, notably the absence of objective diagnostic criteria: a 'reference standard' for BWI. The absence of such a reference standard made analysis of the relationship between the dressing response and BWI diagnosis challenging, however a point estimate of 68% sensitivity from the study suggests the potential future utility of using a sensor which detects secreted bacterial virulence factors to assist in BWI diagnosis.

scholarly journals A VersaTile-driven platform for rapid hit-to-lead development of engineered lysins

2020 ◽  
Vol 6 (23) ◽  
pp. eaaz1136 ◽  
Author(s):  
H. Gerstmans ◽  
D. Grimon ◽  
D. Gutiérrez ◽  
C. Lood ◽  
A. Rodríguez ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Bacterial Pathogen ◽  
Combinatorial Libraries ◽  
Resistant Bacteria ◽  
Dna Assembly ◽  
Burn Wound ◽  
Development Platform ◽  
High Antibacterial Activity ◽  
Wound Model ◽  
Assembly Method

Health care authorities are calling for new antibacterial therapies to cope with the global emergence of antibiotic-resistant bacteria. Bacteriophage-encoded lysins are a unique class of antibacterials with promising (pre)clinical progress. Custom engineering of lysins allows for the creation of variants against potentially any bacterial pathogen. We here present a high-throughput hit-to-lead development platform for engineered lysins. The platform is driven by VersaTile, a new DNA assembly method for the rapid construction of combinatorial libraries of engineered lysins. We constructed approximately 10,000 lysin variants. Using an iterative screening procedure, we identified a lead variant with high antibacterial activity against Acinetobacter baumannii in human serum and an ex vivo pig burn wound model. This generic platform could offer new opportunities to populate the preclinical pipeline with engineered lysins for diverse (therapeutic) applications.

scholarly journals Transcriptional analysis and target genes discovery of Pseudomonas aeruginosa biofilm developed ex vivo chronic wound model

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaojuan Tan ◽  
Xi Cheng ◽  
Mei Hu ◽  
Yifan Zhang ◽  
Aiqun Jia ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Alkaline Phosphatase ◽  
Chronic Wound ◽  
Ex Vivo ◽  
Wound Infections ◽  
Porcine Skin ◽  
Expression Levels ◽  
Wound Model ◽  
Skin Explants ◽  
Chronic Wound Infections

AbstractBacterial biofilms formation is one of the major reasons for treatment failure in chronic wound infections. Therefore, diagnostic biomarkers remain the best option for prevention and treatment of chronic wound infections by biofilms. Herein, Pseudomonas aeruginosa PAO1 was used to mimic biofilm development in porcine skin explants wells as ex vivo wound model. The microscopic imaging showed that PAO1 in porcine skin explants wells formed micro-colonies at 24 h, developed mushroom-like structure at 48 h, and at 72 h mushroom-like structure disappeared, remaining a thin bacterial lawn. RNA-seq data analysis revealed that the expression levels of genes involved in the type II hxc secretion system were significantly higher in biofilms than in planktonic cells, especially the expression of lapA encoding alkaline phosphatase. However, the expression levels of genes associated with denitrification pathway were markedly decreased in biofilms, especially the transcription of nirS encoding nitrite reductase to produce nitric oxide (NO). Therefore, their expressions and products were further detected using RT-qPCR and biochemical assays, respectively. The results found that the expression of lapA and alkaline phosphatase activity were induced, but the expression of nirS and intracellular NO were reduced at the whole biofilms cycle. The study indicates that LapA and NO would play an important role for P. aeruginosa biofilm formation in chronic wound infections. LapA would serve as potential target to monitor chronic wound infections by P. aeruginosa biofilms. Inducing NO would be used to treat chronic wound infections due to P. aeruginosa biofilms.

scholarly journals Transcriptional Analysis and Target Genes Discovery of Pseudomonas Aeruginosa Biofilm Developed Ex Vivo Chronic Wound Model

2021 ◽  
Author(s):  
Xiaojuan Tan ◽  
Xi Cheng ◽  
Mei Hu ◽  
Yifan Zhang ◽  
Aiqun Jia ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Alkaline Phosphatase ◽  
Chronic Wound ◽  
Ex Vivo ◽  
Wound Infections ◽  
Porcine Skin ◽  
Expression Levels ◽  
Wound Model ◽  
Skin Explants ◽  
Chronic Wound Infections

Abstract Bacterial biofilms formation is one of the major reasons for treatment failure in chronic wound infections. Therefore, diagnostic biomarkers remain the best option for prevention and treatment of chronic wound infections by biofilms. Herein, Pseudomonas aeruginosa PAO1 was used to mimic biofilm development in porcine skin explants wells as ex vivo wound model. The microscopic imaging showed that PAO1 in porcine skin explants wells formed micro-colonies at 24 h, developed mushroom-like structure at 48 h, and at 72 h mushroom-like structure disappeared, remaining a thin bacterial lawn. RNA-seq data analysis revealed that the expression levels of genes involved in the type II hxc secretion system were significantly higher in biofilms than in planktonic cells, especially the expression of lapA encoding alkaline phosphatase. However, the expression levels of genes associated with denitrification pathway were markedly decreased in biofilms, especially the transcription of nirS encoding nitrite reductase to produce nitric oxide (NO). Therefore, their expressions and products were further detected using RT-qPCR and biochemical assays, respectively. The results found that the expression of lapA and alkaline phosphatase activity were induced, but the expression of nirS and intracellular NO were reduced at the whole biofilms cycle. The study indicates that LapA and NO would play an important role for P. aeruginosa biofilm formation in chronic wound infections. LapA would serve as potential target to monitor chronic wound infections by P. aeruginosa biofilms. Inducing NO would be used to treat chronic wound infections due to P. aeruginosa biofilms.

scholarly journals Identification of a juvenile-hormone signaling inhibitor via high-throughput screening of a chemical library

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Takumi Kayukawa ◽  
Kenjiro Furuta ◽  
Keisuke Nagamine ◽  
Tetsuro Shinoda ◽  
Kiyoaki Yonesu ◽  
...  
Keyword(s):  
Juvenile Hormone ◽  
Cell Line ◽  
Signaling Pathway ◽  
High Throughput ◽  
High Throughput Screening ◽  
Large Scale ◽  
Ex Vivo ◽  
Agricultural Field ◽  
Chemical Library ◽  
Field Development

Abstract Insecticide resistance has recently become a serious problem in the agricultural field. Development of insecticides with new mechanisms of action is essential to overcome this limitation. Juvenile hormone (JH) is an insect-specific hormone that plays key roles in maintaining the larval stage of insects. Hence, JH signaling pathway is considered a suitable target in the development of novel insecticides; however, only a few JH signaling inhibitors (JHSIs) have been reported, and no practical JHSIs have been developed. Here, we established a high-throughput screening (HTS) system for exploration of novel JHSIs using a Bombyx mori cell line (BmN_JF&AR cells) and carried out a large-scale screening in this cell line using a chemical library. The four-step HTS yielded 69 compounds as candidate JHSIs. Topical application of JHSI48 to B. mori larvae caused precocious metamorphosis. In ex vivo culture of the epidermis, JHSI48 suppressed the expression of the Krüppel homolog 1 gene, which is directly activated by JH-liganded receptor. Moreover, JHSI48 caused a parallel rightward shift in the JH response curve, suggesting that JHSI48 possesses a competitive antagonist-like activity. Thus, large-scale HTS using chemical libraries may have applications in development of future insecticides targeting the JH signaling pathway.

scholarly journals Wound Healing Composite Materials of Bacterial Cellulose and Zinc Oxide Nanoparticles with Immobilized Betulin Diphosphate

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 713
Author(s):  
Nina Melnikova ◽  
Alexander Knyazev ◽  
Viktor Nikolskiy ◽  
Peter Peretyagin ◽  
Kseniia Belyaeva ◽  
...  
Keyword(s):  
Wound Healing ◽  
Zinc Oxide ◽  
Bacterial Cellulose ◽  
Zinc Oxide Nanoparticles ◽  
Wound Dressings ◽  
Oxide Nanoparticles ◽  
Burn Wound ◽  
Zno Nps ◽  
Wound Model ◽  
And Oxidative Stress

A design of new nanocomposites of bacterial cellulose (BC) and betulin diphosphate (BDP) pre-impregnated into the surface of zinc oxide nanoparticles (ZnO NPs) for the production of wound dressings is proposed. The sizes of crystalline BC and ZnO NPs (5–25%) corresponded to 5–6 nm and 10–18 nm, respectively (powder X-ray diffractometry (PXRD), Fourier-infrared (FTIR), ultraviolet (UV), atomic absorption (AAS) and photoluminescence (PL) spectroscopies). The biological activity of the wound dressings “BC-ZnO NPs-BDP” was investigated in rats using a burn wound model. Morpho-histological studies have shown that more intensive healing was observed during treatment with hydrophilic nanocomposites than the oleophilic standard (ZnO NPs-BDP oleogel; p < 0.001). Treatment by both hydrophilic and lipophilic agents led to increases in antioxidant enzyme activity (superoxide dismutase (SOD), catalase) in erythrocytes and decreases in the malondialdehyde (MDA) concentration by 7, 10 and 21 days (p < 0.001). The microcirculation index was restored on the 3rd day after burn under treatment with BC-ZnO NPs-BDP wound dressings. The results of effective wound healing with BC-ZnO NPs-BDP nanocomposites can be explained by the synergistic effect of all nanocomposite components, which regulate oxygenation and microcirculation, reducing hypoxia and oxidative stress in a burn wound.

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