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1.
BMC Microbiol ; 24(1): 270, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39033146

RESUMO

BACKGROUND: The bacterial persistence, responsible for therapeutic failures, can arise from the biofilm formation, which possesses a high tolerance to antibiotics. This threat often occurs when a bone and joint infection is diagnosed after a prosthesis implantation. Understanding the biofilm mechanism is pivotal to enhance prosthesis joint infection (PJI) treatment and prevention. However, little is known on the characteristics of Cutibacterium acnes biofilm formation, whereas this species is frequently involved in prosthesis infections. METHODS: In this study, we compared the biofilm formation of C. acnes PJI-related strains and non-PJI-related strains on plastic support and textured titanium alloy by (i) counting adherent and viable bacteria, (ii) confocal scanning electronic microscopy observations after biofilm matrix labeling and (iii) RT-qPCR experiments. RESULTS: We highlighted material- and strain-dependent modifications of C. acnes biofilm. Non-PJI-related strains formed aggregates on both types of support but with different matrix compositions. While the proportion of polysaccharides signal was higher on plastic, the proportions of polysaccharides and proteins signals were more similar on titanium. The changes in biofilm composition for PJI-related strains was less noticeable. For all tested strains, biofilm formation-related genes were more expressed in biofilm formed on plastic that one formed on titanium. Moreover, the impact of C. acnes internalization in osteoblasts prior to biofilm development was also investigated. After internalization, one of the non-PJI-related strains biofilm characteristics were affected: (i) a lower quantity of adhered bacteria (80.3-fold decrease), (ii) an increase of polysaccharides signal in biofilm and (iii) an activation of biofilm gene expressions on textured titanium disk. CONCLUSION: Taken together, these results evidenced the versatility of C. acnes biofilm, depending on the support used, the bone environment and the strain.


Assuntos
Biofilmes , Infecções Relacionadas à Prótese , Titânio , Biofilmes/crescimento & desenvolvimento , Infecções Relacionadas à Prótese/microbiologia , Humanos , Aderência Bacteriana , Propionibacteriaceae/fisiologia , Propionibacteriaceae/genética , Propionibacteriaceae/efeitos dos fármacos , Próteses e Implantes/microbiologia , Osso e Ossos/microbiologia , Plásticos , Ligas , Propriedades de Superfície
2.
Molecules ; 28(3)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36770646

RESUMO

This work studies two copper-based alloys as potential antimicrobial weapons for sectors where surface hygiene is essential. Effects of different alloying elements addition at the same Cu content (92.5% by weight) on the corrosion resistance and the antibacterial performance of two copper alloys were studied in an aerated disinfectant solution (0.25% v/v Aniosurf Premium (D)) by electrochemical corrosion, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectroscopy (ToF-SIMS) and antibacterial tests. Results showed that the nature of the alloying elements had a clear influence on the corrosion resistance and antibacterial performance. Electrochemical impedance results and surface analyses demonstrate the presence of organic compounds bound on the substrate and that a film covers part of the total active surface and may act as a protective barrier by preventing the interaction between metal and solution, decreasing the antimicrobial performance of copper-based materials. Low zinc and silicon contents in copper alloys allows for better aging behavior in D solution while maintaining good antibacterial performance. The XPS and ToF-SIMS results indicated that artificial aging in disinfectant enhanced Cu enrichment in the organic film formed, which could effectively stimulate the release of Cu ions from the surface.


Assuntos
Cobre , Desinfetantes , Cobre/química , Ligas/farmacologia , Ligas/química , Desinfetantes/farmacologia , Corrosão , Antibacterianos/farmacologia , Antibacterianos/química , Teste de Materiais
3.
Int J Mol Sci ; 23(22)2022 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-36430871

RESUMO

Osteoblasts are bone-forming and highly active cells participating in bone homeostasis. In the case of osteomyelitis and more specifically prosthetic joint infections (PJI) for which Staphylococcus aureus (S. aureus) is mainly involved, the interaction between osteoblasts and S. aureus results in impaired bone homeostasis. If, so far, most of the studies of osteoblasts and S. aureus interactions were focused on osteoblast response following direct interactions with co-culture and/or internalization models, less is known about the effect of osteoblast factors on S. aureus biofilm formation. In the present study, we investigated the effect of human osteoblast culture supernatant on methicillin sensitive S. aureus (MSSA) SH1000 and methicillin resistant S. aureus (MRSA) USA300. Firstly, Saos-2 cell line was incubated with either medium containing TNF-α to mimic the inflammatory periprosthetic environment or with regular medium. Biofilm biomass was slightly increased for both strains in the presence of culture supernatant collected from Saos-2 cells, stimulated or not with TNF-α. In such conditions, SH1000 was able to develop microcolonies, suggesting a rearrangement in biofilm organization. However, the biofilm matrix and regulation of genes dedicated to biofilm formation were not substantially changed. Secondly, culture supernatant obtained from primary osteoblast culture induced varied response from SH1000 strain depending on the different donors tested, whereas USA300 was only slightly affected. This suggested that the sensitivity to bone cell secretions is strain dependent. Our results have shown the impact of osteoblast secretions on bacteria and further identification of involved factors will help to manage PJI.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Staphylococcus aureus , Meios de Cultivo Condicionados/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Antibacterianos/farmacologia , Infecções Estafilocócicas/microbiologia , Biofilmes , Osteoblastos
4.
Int J Mol Sci ; 23(13)2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35806233

RESUMO

In inflammatory diseases, polymorphonuclear neutrophils (PMNs) are known to produce elevated levels of pro-inflammatory cytokines and proteases. To limit ensuing exacerbated cell responses and tissue damage, novel therapeutic agents are sought. 4aa and 4ba, two pyridazinone-scaffold-based phosphodiesterase-IV inhibitors are compared in vitro to zardaverine for their ability to: (1) modulate production of pro-inflammatory mediators, reactive oxygen species (ROS), and phagocytosis; (2) modulate degranulation by PMNs after transepithelial lung migration. Compound 4ba and zardaverine were tested in vivo for their ability to limit tissue recruitment of PMNs in a murine air pouch model. In vitro treatment of lipopolysaccharide-stimulated PMNs with compounds 4aa and 4ba inhibited the release of interleukin-8, tumor necrosis factor-α, and matrix metalloproteinase-9. PMNs phagocytic ability, but not ROS production, was reduced following treatment. Using a lung inflammation model, we proved that PMNs transmigration led to reduced expression of the CD16 phagocytic receptor, which was significantly blunted after treatment with compound 4ba or zardaverine. Using the murine air pouch model, LPS-induced PMNs recruitment was significantly decreased upon addition of compound 4ba or zardaverine. Our data suggest that new pyridazinone derivatives have therapeutic potential in inflammatory diseases by limiting tissue recruitment and activation of PMNs.


Assuntos
Neutrófilos , Fagocitose , Animais , Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/farmacologia , Camundongos , Neutrófilos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Migração Transendotelial e Transepitelial
5.
Nanomedicine ; 29: 102256, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32615337

RESUMO

In bone tissue engineering, stem cells are known to form inhomogeneous bone-like nodules on a micrometric scale. Herein, micro- and nano-infrared (IR) micro-spectroscopies were used to decipher the chemical composition of the bone-like nodule. Histological and immunohistochemical analyses revealed a cohesive tissue with bone-markers positive cells surrounded by dense mineralized type-I collagen. Micro-IR gathered complementary information indicating a non-mature collagen at the top and periphery and a mature collagen within the nodule. Atomic force microscopy combined to IR (AFM-IR) analyses showed distinct spectra of "cell" and "collagen" rich areas. In contrast to the "cell" area, spectra of "collagen" area revealed the presence of carbohydrate moieties of collagen and/or the presence of glycoproteins. However, it was not possible to determine the collagen maturity, due to strong bands overlapping and/or possible protein orientation effects. Such findings could help developing protocols to allow a reliable characterization of in vitro generated complex bone tissues.


Assuntos
Desenvolvimento Ósseo/efeitos dos fármacos , Colágeno/genética , Durapatita/uso terapêutico , Engenharia Tecidual , Colágeno/química , Humanos , Microscopia de Força Atômica , Transplante de Células-Tronco , Células-Tronco/efeitos dos fármacos
6.
J Periodontal Res ; 54(6): 589-600, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31215656

RESUMO

The purpose of this systematic review was to establish if patients suffering from periodontal diseases present differences in the expression or production of cationic antimicrobial peptides in saliva, gingival fluid, and periodontal tissues. Periodontal diseases are among the most common chronic diseases worldwide and share similar etiological or risk factors (genetic and/or environmental) with other systemic disorders. Over the last decade, an increasing number of publications have suggested the implication of antimicrobial peptides (AMPs) in periodontal and oral tissues conditions. Literature searches were conducted through MEDLINE-PubMed and EMBASE databases which identified 1267 publications. Only clinical studies that focused on assays of the expression and/or production of AMPs in human adult oral fluids (gingival crevicular fluid or saliva) or in oral tissues were retained and finally seventy-four publications meeting inclusion criteria were included. Cathelicidin, α- and ß-defensins 1-3 are the most documented AMPs regarding periodontal status. Significant correlations between clinical periodontal indexes (PD, CAL) and/or bacteriological index and LL37 level were retrieved. Data remain inconsistent between the studies for hBDs mainly due to heterogeneity of the results, periodontal disease diagnostic criteria and assaying technique employed. Given their role in innate immunity and their antimicrobial functions, LL-37 and α-defensins may be eligible as periodontal clinical biomarkers and could be an interesting way for therapeutic development.


Assuntos
Peptídeos Catiônicos Antimicrobianos/análise , Doenças Periodontais/fisiopatologia , Líquido do Sulco Gengival/química , Humanos , Índice Periodontal , Saliva/química
7.
J Clin Periodontol ; 45(5): 524-537, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29446150

RESUMO

AIM: Antimicrobial peptides (AMPs) are one of the most active components of innate immunity and have characteristics that could place them at the heart of the pathogenesis of periodontal disease. This study investigated differences in the expression of AMP coding genes obtained using a simple harvesting technique, gingival smear, between two groups of patients: chronic periodontitis subjects versus healthy ones. MATERIALS AND METHODS: Twenty-three patients were enrolled in two groups: 12 were diagnosed with moderate or severe generalized chronic periodontitis, and 11 were diagnosed as clinically healthy. Gingival smears were retrieved and studied using reverse transcription-quantitative PCR (RT-qPCR) after mRNA purification. RESULTS: Fifteen gene expressions were obtained using real-time RT-qPCR. Three AMP genes, histatin 3 (HTN3), α-defensin 4 (DEFA4) and lysozyme C (LYZ), presented different expression levels in periodontitis patients compared with healthy subjects. The relative expression level of DEFA4 appeared to be a protective factor against periodontitis. CONCLUSION: Gingival smears studied by RT-qPCR may be used to assess the expression of AMPs coding genes. A lack of expression of DEFA4 could be a potential indicator of periodontitis status.


Assuntos
Periodontite Crônica/genética , Histatinas/genética , Muramidase/genética , alfa-Defensinas/genética , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Reação em Cadeia da Polimerase em Tempo Real
8.
Int J Mol Sci ; 19(11)2018 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-30400326

RESUMO

The use of inorganic calcium/phosphate supplemented with biopolymers has drawn lots of attention in bone regenerative medicine. While inflammation is required for bone healing, its exacerbation alters tissue regeneration/implants integration. Inspired by bone composition, a friendly automated spray-assisted system was used to build bioactive and osteoinductive calcium phosphate/chitosan/hyaluronic acid substrate (CaP-CHI-HA). Exposing monocytes to CaP-CHI-HA resulted in a secretion of pro-healing VEGF and TGF-ß growth factors, TNF-α, MCP-1, IL-6 and IL-8 pro-inflammatory mediators but also IL-10 anti-inflammatory cytokine along with an inflammatory index below 1.5 (versus 2.5 and 7.5 following CaP and LPS stimulation, respectively). Although CD44 hyaluronic acid receptor seems not to be involved in the inflammatory regulation, results suggest a potential role of chemical composition and calcium release from build-up substrates, in affecting the intracellular expression of a calcium-sensing receptor. Herein, our findings indicate a great potential of CaP-CHI-HA in providing required inflammation-healing balance, favorable for bone healing/regeneration.


Assuntos
Substitutos Ósseos/farmacologia , Fosfatos de Cálcio/farmacologia , Quitosana/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Ácido Hialurônico/farmacologia , Regeneração Óssea/genética , Regeneração Óssea/imunologia , Substitutos Ósseos/química , Osso e Ossos/citologia , Osso e Ossos/metabolismo , Fosfatos de Cálcio/química , Quimiocina CCL2/genética , Quimiocina CCL2/imunologia , Quitosana/química , Regulação da Expressão Gênica/imunologia , Humanos , Receptores de Hialuronatos/genética , Receptores de Hialuronatos/imunologia , Ácido Hialurônico/química , Inflamação , Interleucinas/genética , Interleucinas/imunologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/imunologia , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo , Receptores de Detecção de Cálcio/genética , Receptores de Detecção de Cálcio/imunologia , Transdução de Sinais , Células THP-1 , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/imunologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/imunologia , Vinculina/genética , Vinculina/imunologia
9.
J Pathol ; 240(1): 50-60, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27235726

RESUMO

Bone fragility and loss are a significant cause of morbidity in patients with cystic fibrosis (CF), and the lack of effective therapeutic options means that treatment is more often palliative rather than curative. A deeper understanding of the pathogenesis of CF-related bone disease (CFBD) is necessary to develop new therapies. Defective CF transmembrane conductance regulator (CFTR) protein and chronic inflammation in bone are important components of the CFBD development. The receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) drive the regulation of bone turnover. To investigate their roles in CFBD, we evaluated the involvement of defective CFTR in their production level in CF primary human osteoblasts with and without inflammatory stimulation, in the presence or not of pharmacological correctors of the CFTR. No major difference in cell ultrastructure was noted between cultured CF and non-CF osteoblasts, but a delayed bone matrix mineralization was observed in CF osteoblasts. Strikingly, resting CF osteoblasts exhibited strong production of RANKL protein, which was highly localized at the cell membrane and was enhanced in TNF (TNF-α) or IL-17-stimulated conditions. Under TNF stimulation, a defective response in OPG production was observed in CF osteoblasts in contrast to the elevated OPG production of non-CF osteoblasts, leading to an elevated RANKL-to-OPG protein ratio in CF osteoblasts. Pharmacological inhibition of CFTR chloride channel conductance in non-CF osteoblasts replicated both the decreased OPG production and the enhanced RANKL-to-OPG ratio. Interestingly, using CFTR correctors such as C18, we significantly reduced the production of RANKL by CF osteoblasts, in both resting and TNF-stimulated conditions. In conclusion, the overexpression of RANKL and high membranous RANKL localization in osteoblasts are related to defective CFTR, and may worsen bone resorption, leading to bone loss in patients with CF. Targeting osteoblasts with CFTR correctors may represent an effective strategy to treat CFBD. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Doenças Ósseas/metabolismo , Fibrose Cística/metabolismo , Osteoblastos/metabolismo , Ligante RANK/metabolismo , Adolescente , Adulto , Doenças Ósseas/complicações , Doenças Ósseas/patologia , Membrana Celular/metabolismo , Fibrose Cística/complicações , Fibrose Cística/patologia , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Suscetibilidade a Doenças , Humanos , Interleucina-17/farmacologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/patologia , Osteoprotegerina/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Adulto Jovem
10.
Int J Mol Sci ; 18(10)2017 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-29065466

RESUMO

Maintenance of mesenchymal stem cells (MSCs) requires a tissue-specific microenvironment (i.e., niche), which is poorly represented by the typical plastic substrate used for two-dimensional growth of MSCs in a tissue culture flask. The objective of this study was to address the potential use of collagen-based medical devices (HEMOCOLLAGENE®, Saint-Maur-des-Fossés, France) as mimetic niche for MSCs with the ability to preserve human MSC stemness in vitro. With a chemical composition similar to type I collagen, HEMOCOLLAGENE® foam presented a porous and interconnected structure (>90%) and a relative low elastic modulus of around 60 kPa. Biological studies revealed an apparently inert microenvironment of HEMOCOLLAGENE® foam, where 80% of cultured human MSCs remained viable, adopted a flattened morphology, and maintained their undifferentiated state with basal secretory activity. Thus, three-dimensional HEMOCOLLAGENE® foams present an in vitro model that mimics the MSC niche with the capacity to support viable and quiescent MSCs within a low stiffness collagen I scaffold simulating Wharton's jelly. These results suggest that haemostatic foam may be a useful and versatile carrier for MSC transplantation for regenerative medicine applications.


Assuntos
Microambiente Celular , Colágeno , Células-Tronco Mesenquimais , Preservação Biológica/métodos , Medicina Regenerativa/instrumentação , Humanos
11.
Planta Med ; 82(15): 1351-1358, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27352384

RESUMO

Wood residues produced from forestry activities represent an interesting source of biologically active, high value-added secondary metabolites. In this study, 30 extracts from 10 barks of deciduous and coniferous tree species were investigated for their potential dermo-cosmetic use. The extracts were obtained from Fagus sylvatica, Quercus robur, Alnus glutinosa, Prunus avium, Acer pseudoplatanus, Fraxinus excelsior, Populus robusta, Larix decidua, Picea abies, and Populus tremula after three successive solid/liquid extractions of the barks with n-heptane, methanol, and methanol/water. All extracts were evaluated for their radical scavenging capacity, for their elastase, collagenase, and tyrosinase inhibitory activities, as well as for their antibacterial activity against gram-positive Staphylococcus aureus. In parallel, the global metabolite profiles of all extracts were established by 1D and 2D NMR and related to their biological activity. The results showed that the methanol extracts of Q. robur, A. glutinosa, L. decidua, and P. abies barks exhibit particularly high activities on most bioassays, suggesting their promising use as active ingredients in the dermo-cosmetic industry.


Assuntos
Fármacos Dermatológicos/farmacologia , Casca de Planta/química , Extratos Vegetais/farmacologia , Árvores/química , Animais , Antibacterianos/farmacologia , Fármacos Dermatológicos/química , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Espectroscopia de Ressonância Magnética , Monofenol Mono-Oxigenase/antagonistas & inibidores , Elastase Pancreática/antagonistas & inibidores , Extratos Vegetais/química , Staphylococcus aureus/efeitos dos fármacos
12.
Molecules ; 21(11)2016 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-27879645

RESUMO

Common spruce (Picea abies L.) is a fast-growing coniferous tree, widely used in several countries for the production of sawn wood, timber and pulp. During this industrial exploitation, large quantities of barks are generated as waste materials. The aim of this study was the bio-guided investigation and the effective recovery of methanol-soluble metabolites of common spruce bark for the development of new dermo-cosmetic agents. The active methanol extract was initially fractionated by Centrifugal Partition Chromatography (CPC) using a triphasic solvent system in a step-gradient elution mode. All resulting fractions were evaluated for their antibacterial activity, antioxidant activity and their capability to inhibit tyrosinase, elastase and collagenase activity. In parallel, the chemical composition of each fraction was established by combining a 13C-NMR dereplication approach and 2D-NMR analyses. As a result, fourteen secondary metabolites corresponding to stilbene, flavonoid and phenolic acid derivatives were directly identified in the CPC fractions. A high amount (0.93 g) of E-astringin was recovered from 3 g of crude extract in a single 125 min run. E-Astringin significantly induced the tyrosinase activity while E-piceid, taxifolin, and taxifolin-3'-O-glucopyranoside exhibited significant anti-tyrosinase activity. The above compounds showed important anti-collagenase and antimicrobial activities, thus providing new perspectives for potential applications as cosmetic ingredients.


Assuntos
Cosméticos/química , Cosméticos/isolamento & purificação , Metanol/química , Picea/química , Casca de Planta/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Fracionamento Químico/métodos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Solubilidade
13.
Life (Basel) ; 14(2)2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38398765

RESUMO

Disinfection in the hospital environment remains challenging, especially for wide and structurally complex objects such as beds or wheelchairs. Indeed, the regular disinfection of these objects with chemicals is manually carried out by healthcare workers and is fastidious and time-consuming. Alternative antibacterial techniques were thus proposed in the past decades, including the use of naturally antimicrobial UVC. Here, the antibacterial efficiency of a large UVC box built to accommodate wheelchairs was investigated through testing bacterial burden reductions on various parts of a wheelchair, with various support types and with several treatment durations. The results demonstrate a time-dependent antibacterial effect, with a strong burden reduction at only five minutes of treatment (>3-log median reduction in Escherichia coli and Staphylococcus epidermidis). The UVC flux and residual bacterial burden both significantly varied depending on the spatial location on the wheelchair. However, the nature of the support impacted the antibacterial efficiency even more, with residual bacterial burdens being the lowest on rigid materials (steel, plastics) and being the highest on tissue. On metallic samples, the nature of the alloy and surface treatment had various impacts on the antibacterial efficiency of the UVC. This study highlights the efficiency of the tested UVC box to efficiently and quickly decontaminate complex objects such as wheelchairs, but also gives rise to the warning to focus on rigid materials and avoid porous materials in the conception of objects, so as to ensure the efficiency of UVC decontamination.

14.
Antibiotics (Basel) ; 13(3)2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38534722

RESUMO

Copper (I) oxide (cuprite) is a material widely used nowadays, and its versatility is further amplified when it is brought to the nanometric size. Among the possible applications of this nanomaterial, one of the most interesting is that in the medical field. This paper presents a cuprite nanopowder study with the aim of employing it in medical applications. With regards to the environmental context, the synthesis used is related to green chemistry since the technique (out-of-phase pulsed electrochemistry) uses few chemical products via electricity consumption and soft conditions of temperature and pressure. After different physico-chemical characterizations, the nanopowder was tested on the Candida albicans to determine its fungicide activity and on human blood to estimate its hemocompatibility. The results show that 2 mg of this nanopowder diluted in 30 µL Sabouraud broth was able to react with Candida albicans. The hemocompatibility tests indicate that for 25 to 100 µg/mL of nanopowder in an aqueous medium, the powder was not toxic for human blood (no hemolysis nor platelet aggregation) but promoted blood coagulation. It appears, therefore, as a potential candidate for the functionalization of matrices for medical applications (wound dressing or operating field, for example).

15.
J Biol Chem ; 287(42): 34883-34894, 2012 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-22927440

RESUMO

There is accumulating evidence that following bacterial infection, the massive recruitment and activation of the phagocytes, neutrophils, is accompanied with the extracellular release of active neutrophil elastase (NE), a potent serine protease. Using NE-deficient mice in a clinically relevant model of Pseudomonas aeruginosa-induced pneumonia, we provide compelling in vivo evidence that the absence of NE was associated with decreased protein and transcript levels of the proinflammatory cytokines TNF-α, MIP-2, and IL-6 in the lungs, coinciding with increased mortality of mutant mice to infection. The implication of NE in the induction of cytokine expression involved at least in part Toll-like receptor 4 (TLR-4). These findings were further confirmed following exposure of cultured macrophages to purified NE. Together, our data suggest strongly for the first time that NE not only plays a direct antibacterial role as it has been previously reported, but released active enzyme can also modulate cytokine expression, which contributes to host protection against P. aeruginosa. In light of our findings, the long held view that considers NE as a prime suspect in P. aeruginosa-associated diseases will need to be carefully reassessed. Also, therapeutic strategies aiming at NE inhibition should take into account the physiologic roles of the enzyme.


Assuntos
Citocinas/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata , Elastase de Leucócito/imunologia , Pneumonia Bacteriana/imunologia , Infecções por Pseudomonas/imunologia , Pseudomonas aeruginosa/imunologia , Animais , Citocinas/biossíntese , Citocinas/genética , Elastase de Leucócito/genética , Elastase de Leucócito/metabolismo , Pulmão/enzimologia , Pulmão/imunologia , Pulmão/microbiologia , Pulmão/patologia , Camundongos , Camundongos Knockout , Pneumonia Bacteriana/enzimologia , Pneumonia Bacteriana/genética , Pneumonia Bacteriana/microbiologia , Pneumonia Bacteriana/patologia , Infecções por Pseudomonas/enzimologia , Infecções por Pseudomonas/genética , Infecções por Pseudomonas/patologia , Pseudomonas aeruginosa/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Receptor 4 Toll-Like/metabolismo
16.
Cytometry A ; 83(2): 235-41, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23212973

RESUMO

The spatial organization of proteins in a cell population or in tissues is an important parameter to study the functionality of biological specimens. In this article, we have focused on tight junctions which form network-like features in immunofluorescence microscopy images. Usually, the organization or disorganization of tight junctions is noticed qualitatively. The aim of this article is to present a simple method to quantify the organization level of tight junction network using image analysis with a dedicated macro developed with Image J software. The method has been validated with simulated images displaying regular decrease of network organization. Then, the macro has been applied to immunofluorescence microscopy images of cells in culture and of tissue sections.


Assuntos
Células Epiteliais/metabolismo , Processamento de Imagem Assistida por Computador , Junções Íntimas/metabolismo , Animais , Células Cultivadas , Simulação por Computador , Humanos , Pulmão/patologia , Lesão Pulmonar/induzido quimicamente , Lesão Pulmonar/patologia , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Elastase Pancreática , Pseudomonas aeruginosa/química , Pseudomonas aeruginosa/imunologia , Proteína da Zônula de Oclusão-1/metabolismo
17.
Pathogens ; 12(3)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36986306

RESUMO

Infections, which interfere with bone regeneration, may be a critical issue to consider during the development of biomimetic material. Calcium phosphate (CaP) and type I collagen substrates, both suitable for bone-regeneration dedicated scaffolds, may favor bacterial adhesion. Staphylococcus aureus possesses adhesins that allow binding to CaP or collagen. After their adhesion, bacteria may develop structures highly tolerant to immune system attacks or antibiotic treatments: the biofilms. Thus, the choice of material used for scaffolds intended for bone sites is essential to provide devices with the ability to prevent bone and joint infections by limiting bacterial adhesion. In this study, we compared the adhesion of three different S. aureus strains (CIP 53.154, SH1000, and USA300) on collagen- and CaP-coating. Our objective was to evaluate the capacity of bacteria to adhere to these different bone-mimicking coated supports to better control the risk of infection. The three strains were able to adhere to CaP and collagen. The visible matrix components were more important on CaP- than on collagen-coating. However, this difference was not reflected in biofilm gene expression for which no change was observed between the two tested surfaces. Another objective was to evaluate these bone-mimicking coatings for the development of an in vitro model. Thus, CaP, collagen-coatings, and the titanium-mimicking prosthesis were simultaneously tested in the same bacterial culture. No significant differences were found compared to adhesion on surfaces independently tested. In conclusion, these coatings used as bone substitutes can easily be colonized by bacteria, especially CaP-coating, and must be used with an addition of antimicrobial molecules or strategies to avoid bacterial biofilm development.

18.
PLoS One ; 18(8): e0290820, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37647324

RESUMO

The sterilization of medical devices is paramount to achieve an acceptable level of sterility assurance and to prevent hospital-acquired infections. However, some medical devices cannot be sterilized by usual processes such as autoclave (AC) and gamma-ray irradiation (GI). A new non-thermal plasma (NTP) process using sealed bag that preserves the sterile state of the devices could be used as an alternative sterilization method. The aim of the study was to assess the cytocompatibility of titanium and poly(etheretherketone) (PEEK) surfaces after O2-NTP sterilization compared to GI and AC. MG-63 osteoblast-like cells were seeded on titanium (TA6V) and PEEK disks sterilized by AC, GI and O2-NTP. The cells' viability and proliferation, determined by WST-1 and DNA quantification respectively, were enhanced whatever the material types from 3 to 10 days. When seeded on titanium, MG-63 cells showed a higher viability and proliferation after GI and O2-NTP treatment compared to AC treatment. When cultured on PEEK, MG-63 cells showed a higher viability after O2-NTP treatment. No difference of proliferation was observed whatever the sterilization processes. The cell colonization of the materials' surface was confirmed by scanning electron microscopy. Lactate dehydrogenase (LDH) assay revealed no cytotoxicity. Thus, O2-NTP led to similar cell responses to AC and GI and could be a cost-effective alternative process to the usual sterilization methods for fragile medical devices.


Assuntos
Infertilidade , Gases em Plasma , Humanos , Titânio/farmacologia , Poli A , Esterilização , Benzofenonas , Gases em Plasma/farmacologia
19.
Biofilm ; 5: 100120, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37125394

RESUMO

The major role and implication of bacterial biofilms in the case of bone and prosthesis infections have been highlighted and often linked to implant colonization. Management strategies of these difficult-to-treat infections consist in surgeries and antibiotic treatment, but the rate of relapse remains high, especially if Staphylococcus aureus, a high-virulent pathogen, is involved. Therapeutic approaches are not adapted to the specific features of biofilm in bone context whereas infectious environment is known to importantly influence biofilm structure. In the present study, we aim to characterize S. aureus SH1000 (methicillin-sensitive strain, MSSA) and USA300 (methicillin-resistant strain, MRSA) biofilm on different surfaces mimicking the periprosthetic environment. As expected, protein adsorption on titanium enhanced the number of adherent bacteria for both strains. On bone explant, USA300 adhered more than SH1000. The simultaneous presence of two different surfaces was also found to change the bacterial behaviour. Thus, proteins adsorption on titanium and bone samples (from bank or directly recovered after an arthroplasty) were found to be key parameters that influence S. aureus biofilm formation: adhesion, matrix production and biofilm-related gene regulation. These results highlighted the need for new biofilm models, more relevant with the infectious environment by using adapted culture medium and presence of surfaces that are representative of in situ conditions to better evaluate therapeutic strategies against biofilm.

20.
J Nat Prod ; 74(2): 163-8, 2011 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-21288041

RESUMO

Three new bidesmosidic saponins (1-3) and a new ursane triterpenoid, 2α,3ß,11α,23-tetrahydroxyurs-12-en-28-oic acid (4), along with seven known compounds, were isolated from a methanolic extract of the leaves of Symplocos lancifolia. The bidesmosidic saponins were found to possess the same sugar unit part, composed of two ß-d-glucose moieties and one α-l-rhamnose moiety, linked to maslinic acid, arjunolic acid, and asiatic acid, respectively. Their structures were elucidated by interpretation of their 1D and 2D NMR spectra and completed by analysis of the HRESIMS data. The antibacterial activity of the isolated triterpenoids was evaluated against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa, and several showed activity against Gram-positive bacteria.


Assuntos
Antibacterianos/isolamento & purificação , Magnoliopsida/química , Saponinas/isolamento & purificação , Triterpenos/isolamento & purificação , Antibacterianos/química , Antibacterianos/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Folhas de Planta/química , Pseudomonas aeruginosa/efeitos dos fármacos , Saponinas/química , Saponinas/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Triterpenos/química , Triterpenos/farmacologia , Vietnã
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