Inflammatory responses to micro/nano-structured titanium surfaces with silver nanoparticles in vitro

AbstractWe aimed to isolate Acinetobacter baumannii (A. baumannii) from wound infections, determine their resistance and virulence profile, and assess the impact of Silver nanoparticles (AgNPs) on the bacterial growth, virulence and biofilm-related gene expression. AgNPs were synthesized and characterized using TEM, XRD and FTIR spectroscopy. A. baumannii (n = 200) were isolated and identified. Resistance pattern was determined and virulence genes (afa/draBC, cnf1, cnf2, csgA, cvaC, fimH, fyuA, ibeA, iutA, kpsMT II, PAI, papC, PapG II, III, sfa/focDE and traT) were screened using PCR. Biofilm formation was evaluated using Microtiter plate method. Then, the antimicrobial activity of AgNPs was evaluated by the well-diffusion method, growth kinetics and MIC determination. Inhibition of biofilm formation and the ability to disperse biofilms in exposure to AgNPs were evaluated. The effect of AgNPs on the expression of virulence and biofilm-related genes (bap, OmpA, abaI, csuA/B, A1S_2091, A1S_1510, A1S_0690, A1S_0114) were estimated using QRT-PCR. In vitro infection model for analyzing the antibacterial activity of AgNPs was done using a co-culture infection model of A. baumannii with human fibroblast skin cell line HFF-1 or Vero cell lines. A. baumannii had high level of resistance to antibiotics. Most of the isolates harbored the fimH, afa/draBC, cnf1, csgA and cnf2, and the majority of A. baumannii produced strong biofilms. AgNPs inhibited the growth of A. baumannii efficiently with MIC ranging from 4 to 25 µg/ml. A. baumannii showed a reduced growth rate in the presence of AgNPs. The inhibitory activity and the anti-biofilm activity of AgNPs were more pronounced against the weak biofilm producers. Moreover, AgNPs decreased the expression of kpsMII , afa/draBC,bap, OmpA, and csuA/B genes. The in vitro infection model revealed a significant antibacterial activity of AgNPs against extracellular and intracellular A. baumannii. AgNPs highly interrupted bacterial multiplication and biofilm formation. AgNPs downregulated the transcription level of important virulence and biofilm-related genes. Our findings provide an additional step towards understanding the mechanisms by which sliver nanoparticles interfere with the microbial spread and persistence.

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The Design, Characterization and Antibacterial Activity of Heat and Silver Crosslinked Poly(Vinyl Alcohol) Hydrogel Forming Dressings Containing Silver Nanoparticles

Nanomaterials ◽

10.3390/nano11010096 ◽

2021 ◽

Vol 11 (1) ◽

pp. 96

Author(s):

John Jackson ◽

Helen Burt ◽

Dirk Lange ◽

In Whang ◽

Robin Evans ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Activity ◽

Silver Nitrate ◽

Vinyl Alcohol ◽

Unmet Need ◽

Chemical Characterization ◽

Wound Dressings ◽

Poly Vinyl Alcohol ◽

Burn Wound

The prompt treatment of burn wounds is essential but can be challenging in remote parts of Africa, where burns from open fires are a constant hazard for children and suitable medical care may be far away. Consequently, there is an unmet need for an economical burn wound dressing with a sustained antimicrobial activity that might be manufactured locally at low cost. This study describes and characterizes the novel preparation of a silver nitrate-loaded/poly(vinyl alcohol) (PVA) film. Using controlled heating cycles, films may be crosslinked with in situ silver nanoparticle production using only a low heat oven and little technical expertise. Our research demonstrated that heat-curing of PVA/silver nitrate films converted the silver to nanoparticles. These films swelled in water to form a robust, wound-compatible hydrogel which exhibited controlled release of the antibacterial silver nanoparticles. An optimal formulation was obtained using 5% (w/w) silver nitrate in PVA membrane films that had been heated at 140 °C for 90 min. Physical and chemical characterization of such films was complemented by in vitro studies that confirmed the effective antibacterial activity of the released silver nanoparticles against both gram positive and negative bacteria. Overall, these findings provide economical and simple methods to manufacture stable, hydrogel forming wound dressings that release antibiotic silver over prolonged periods suitable for emergency use in remote locations.

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Fabrication of Silver Nanoparticles Supported on Rice Straw: In Vitro Antibacterial Activity and its Heterogeneous Catalysis in the Degradation of 4-Nitrophenol

BioResources ◽

10.15376/biores.11.2.3691-3708 ◽

2016 ◽

Vol 11 (2) ◽

Cited By ~ 4

Author(s):

Roshanak Khandanlou ◽

Gek Cheng Ngoh ◽

Wen Tong Chong ◽

Saadi Bayat ◽

Elnaz Saki

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Activity ◽

Heterogeneous Catalysis ◽

Rice Straw ◽

In Vitro Antibacterial Activity

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A Comparative Transcriptome Analysis of Human and Porcine Choroid Plexus Cells in Response to Streptococcus suis Serotype 2 Infection Points to a Role of Hypoxia

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.639620 ◽

2021 ◽

Vol 11 ◽

Author(s):

Alexa N. Lauer ◽

Rene Scholtysik ◽

Andreas Beineke ◽

Christoph Georg Baums ◽

Kristin Klose ◽

...

Keyword(s):

Epithelial Cells ◽

Inflammatory Response ◽

Choroid Plexus ◽

Cellular Proliferation ◽

Inflammatory Responses ◽

Streptococcus Suis ◽

Gene Set Enrichment Analysis ◽

Rna Seq

Streptococcus suis (S. suis) is an important opportunistic pathogen, which can cause septicemia and meningitis in pigs and humans. Previous in vivo observations in S. suis-infected pigs revealed lesions at the choroid plexus (CP). In vitro experiments with primary porcine CP epithelial cells (PCPEC) and human CP epithelial papilloma (HIBCPP) cells demonstrated that S. suis can invade and traverse the CP epithelium, and that the CP contributes to the inflammatory response via cytokine expression. Here, next generation sequencing (RNA-seq) was used to compare global transcriptome profiles of PCPEC and HIBCPP cells challenged with S. suis serotype (ST) 2 infected in vitro, and of pigs infected in vivo. Identified differentially expressed genes (DEGs) were, amongst others, involved in inflammatory responses and hypoxia. The RNA-seq data were validated via quantitative PCR of selected DEGs. Employing Gene Set Enrichment Analysis (GSEA), 18, 28, and 21 enriched hallmark gene sets (GSs) were identified for infected HIBCPP cells, PCPEC, and in the CP of pigs suffering from S. suis ST2 meningitis, respectively, of which eight GSs overlapped between the three different sample sets. The majority of these GSs are involved in cellular signaling and pathways, immune response, and development, including inflammatory response and hypoxia. In contrast, suppressed GSs observed during in vitro and in vivo S. suis ST2 infections included those, which were involved in cellular proliferation and metabolic processes. This study suggests that similar cellular processes occur in infected human and porcine CP epithelial cells, especially in terms of inflammatory response.

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PHYTOCHEMICAL SCREENING AND GAS CHROMATOGRAPHY-MASS SPECTROSCOPY ANALYSIS OF BIOACTIVE COMPOUNDS AND BIOSYNTHESIS OF SILVER NANOPARTICLES USING SPROUT EXTRACTS OF VIGNA RADIATA L. AND THEIR ANTIOXIDANT AND ANTIBACTERIAL ACTIVITY

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2019.v12i2.29253 ◽

2019 ◽

pp. 180-184

Author(s):

SIVAKUMAR T

Keyword(s):

Gas Chromatography ◽

Antioxidant Activity ◽

Silver Nanoparticles ◽

Antibacterial Activity ◽

Mass Spectroscopy ◽

Vigna Radiata ◽

Green Gram ◽

Hexadecanoic Acid ◽

Gas Chromatography Mass Spectroscopy

Objectives: The present study was aimed to investigate the facile synthesis of silver nanoparticles (AgNPs) using the green gram sprout extract (GGSE) of Vigna radiata L. and also in vitro studies of antioxidant and antimicrobial activities. Methods: Gas chromatography-mass spectroscopy techniques have been used for the qualitative and quantitative evaluation of the phytochemicals present in the green gram seedlings. The antioxidant activity of AgNPs and GGSE was analyzed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. In vitro antibacterial activity was performed using the agar well diffusion method. Results: The presence of various secondary metabolites such as flavonoids, steroids, terpenoids, alkaloids, amino acids, polyphenol, glycoside, and protein was found in samples. The major chemical compounds of V. radiata were n-hexadecanoic acid, stigmasterol, caffeine, hexadecanoic acid, cholest-5-en-3-ol (3.beta.)-, and cyclopentane. The percentage of DPPH activity was enhanced on increasing the concentration of AgNPs. In vitro antibacterial effect of the diverse concentrations of AgNPs was investigated against each Gram-negative (Klebsiella aerogenes, and Escherichia coli) and Gram-positive (Bacillus substilis and Staphylococcus aureus) bacterial strains. Conclusion: The result suggests that biosynthesized AgNPs have good antibacterial and antioxidant activity and might be a potential for the bioactive components.

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Silver Nanoparticles Alter Cell Viability Ex Vivo and in Vitro and Induce Proinflammatory Effects in Human Lung Fibroblasts

Nanomaterials ◽

10.3390/nano10091868 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1868

Author(s):

Anna Löfdahl ◽

Andreas Jern ◽

Samuel Flyman ◽

Monica Kåredal ◽

Hanna L Karlsson ◽

...

Keyword(s):

Silver Nanoparticles ◽

Cell Viability ◽

Human Lung ◽

Inflammatory Responses ◽

Ex Vivo ◽

Lung Fibroblasts ◽

Human Lung Fibroblasts ◽

Metabolic Activities ◽

Precision Cut Lung Slices

Silver nanoparticles (AgNPs) are commonly used in commercial and medical applications. However, AgNPs may induce toxicity, extracellular matrix (ECM) changes and inflammatory responses. Fibroblasts are key players in remodeling processes and major producers of the ECM. The aims of this study were to explore the effect of AgNPs on cell viability, both ex vivo in murine precision cut lung slices (PCLS) and in vitro in human lung fibroblasts (HFL-1), and immunomodulatory responses in fibroblasts. PCLS and HFL-1 were exposed to AgNPs with different sizes, 10 nm and 75 nm, at concentrations 2 µg/mL and 10 μg/mL. Changes in synthesis of ECM proteins, growth factors and cytokines were analyzed in HFL-1. Ag10 and Ag75 affected cell viability, with significantly reduced metabolic activities at 10 μg/mL in both PCLS and HFL-1 after 48 h. AgNPs significantly increased procollagen I synthesis and release of IL-8, prostaglandin E2, RANTES and eotaxin, whereas reduced IL-6 release was observed in HFL-1 after 72 h. Our data indicate toxic effects of AgNP exposure on cell viability ex vivo and in vitro with altered procollagen and proinflammatory cytokine secretion in fibroblasts over time. Hence, careful characterizations of AgNPs are of importance, and future studies should include timepoints beyond 24 h.

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A Novel Combination of Vitamin C, Curcumin and Glycyrrhizic Acid Potentially Regulates Immune and Inflammatory Response Associated with Coronavirus Infections: A Perspective from System Biology Analysis

Nutrients ◽

10.3390/nu12041193 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1193 ◽

Cited By ~ 22

Author(s):

Liang Chen ◽

Chun Hu ◽

Molly Hood ◽

Xue Zhang ◽

Lu Zhang ◽

...

Keyword(s):

Immune Response ◽

Vitamin C ◽

Inflammatory Response ◽

Signaling Pathways ◽

System Biology ◽

Glycyrrhizic Acid ◽

Inflammatory Responses ◽

Mapk Signaling ◽

Gene Target

Novel coronaviruses (CoV) have emerged periodically around the world in recent years. The recurrent spreading of CoVs imposes an ongoing threat to global health and the economy. Since no specific therapy for these CoVs is available, any beneficial approach (including nutritional and dietary approach) is worth investigation. Based on recent advances in nutrients and phytonutrients research, a novel combination of vitamin C, curcumin and glycyrrhizic acid (VCG Plus) was developed that has potential against CoV infection. System biology tools were applied to explore the potential of VCG Plus in modulating targets and pathways relevant to immune and inflammation responses. Gene target acquisition, gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment were conducted consecutively along with network analysis. The results show that VCG Plus can act on 88 hub targets which are closely connected and associated with immune and inflammatory responses. Specifically, VCG Plus has the potential to regulate innate immune response by acting on NOD-like and Toll-like signaling pathways to promote interferons production, activate and balance T-cells, and regulate the inflammatory response by inhibiting PI3K/AKT, NF-κB and MAPK signaling pathways. All these biological processes and pathways have been well documented in CoV infections studies. Therefore, our findings suggest that VCG Plus may be helpful in regulating immune response to combat CoV infections and inhibit excessive inflammatory responses to prevent the onset of cytokine storm. However, further in vitro and in vivo experiments are warranted to validate the current findings with system biology tools. Our current approach provides a new strategy in predicting formulation rationale when developing new dietary supplements.

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