In Vitro Visualization and Quantitative Characterization of Pseudomonas aeruginosa Biofilm Growth Dynamics on Polyether Ether Ketone

2021 ◽  
Author(s):  
Carole SL Spake ◽  
Ellis M. Berns ◽  
Lori Sahakian ◽  
Adrian Turcu ◽  
Ahsia Clayton ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Growth Dynamics ◽  
Quantitative Characterization ◽  
Biofilm Growth ◽  
Polyether Ether Ketone ◽  
Ether Ketone

scholarly journals An In Vitro Coumarin-Antibiotic Combination Treatment of Pseudomonas aeruginosa Biofilms

2021 ◽  
Vol 16 (1) ◽  
pp. 1934578X2098774
Author(s):  
Jinpeng Zou ◽  
Yang Liu ◽  
Ruiwei Guo ◽  
Yu Tang ◽  
Zhengrong Shi ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Resistance ◽  
Combination Treatment ◽  
Crude Extract ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antibacterial Properties ◽  
Biofilm Growth ◽  
Antibiotic Combination

The drug resistance of Pseudomonas aeruginosa is a worldwide problem due to its great threat to human health. A crude extract of Angelica dahurica has been proved to have antibacterial properties, which suggested that it may be able to inhibit the biofilm formation of P. aeruginosa; initial exploration had shown that the crude extract could inhibit the growth of P. aeruginosa effectively. After the adaptive dose of coumarin was confirmed to be a potential treatment for the bacteria’s drug resistance, “coumarin-antibiotic combination treatments” (3 coumarins—simple coumarin, imperatorin, and isoimperatorin—combined with 2 antibiotics—ampicillin and ceftazidime) were examined to determine their capability to inhibit P. aeruginosa. The final results showed that (1) coumarin with either ampicillin or ceftazidime significantly inhibited the biofilm formation of P. aeruginosa; (2) coumarin could directly destroy mature biofilms; and (3) the combination treatment can synergistically enhance the inhibition of biofilm formation, which could significantly reduce the usage of antibiotics and bacterial resistance. To sum up, a coumarin-antibiotic combination treatment may be a potential way to inhibit the biofilm growth of P. aeruginosa and provides a reference for antibiotic resistance treatment.

scholarly journals Interfacial Fracture Toughness Comparison of Three Indirect Resin Composites to Dentin and Polyether Ether Ketone Polymer

2020 ◽  
Vol 14 (03) ◽  
pp. 456-461
Author(s):  
Rayhaneh Khalesi ◽  
Mahdi Abbasi ◽  
Zahra Shahidi ◽  
Masoumeh Hasani Tabatabaei ◽  
Zohreh Moradi
Keyword(s):  
Fracture Toughness ◽  
Bond Strength ◽  
Testing Machine ◽  
Composite Resins ◽  
High Wear Resistance ◽  
Luting Cements ◽  
Anterior Teeth ◽  
Polyether Ether Ketone ◽  
Ether Ketone

Abstract Objectives Advances in laboratory composites and their high wear resistance and fracture toughness have resulted in their growing popularity and increasing use for dental restorations. This study sought to assess the fracture toughness of three indirect composites bonded to dental substrate and polyether ether ketone (PEEK) polymer. Materials and Methods This in vitro study was conducted on two groups of dental and polymer substrates. Each substrate was bonded to three indirect composite resins. Sixty blocks (3 × 3 × 12 mm) were made of sound bovine anterior teeth and PEEK polymer. Sixty blocks (3 × 3 × 12 mm) were fabricated of CRIOS (Coltene, Germany), high impact polymer composite (HIPC; Bredent, Germany), and GRADIA (Indirect; GC, Japan) composite resins. Composites were bonded to dentin using Panavia F 2.0 (Kuraray, Japan). For bonding to PEEK, Combo.lign (Bredent) and Visio.Link (Bredent) luting cements were used. In all samples, a single-edge notch was created by a no. 11 surgical blade at the interface. The samples were subjected to 3,500 thermal cycles, and their fracture toughness was measured in a universal testing machine (Zwick/Roell, Germany) by application of four-point flexural load. Statistical Analysis Data were analyzed using one-way analysis of variance, Kruskal–Wallis. Results The fracture toughness of CRIOS–PEEK interface was significantly higher than HIPC–PEEK. The fracture toughness of GRADIA–PEEK was not significantly different from that of HIPC and CRIOS. The fracture toughness of GRADIA–dentin was significantly higher than HIPC–dentin. Conclusion Considering the limitations of this study, GRADIA has the highest bond strength to dentin, while CRIOS shows the highest bond strength to PEEK.

scholarly journals Adhesion Behaviour of Primary Human Osteoblasts and Fibroblasts on Polyether Ether Ketone Compared with Titanium under In Vitro Lipopolysaccharide Incubation

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2739 ◽  
Author(s):  
Korbinian Benz ◽  
Andreas Schöbel ◽  
Marisa Dietz ◽  
Peter Maurer ◽  
Jochen Jackowski
Keyword(s):  
Gene Expression ◽  
Protein Level ◽  
Binding Protein ◽  
Sem Images ◽  
Human Osteoblasts ◽  
Polyether Ether Ketone ◽  
Primary Human Osteoblasts ◽  
Titanium Surfaces ◽  
Ether Ketone

The aim of this in vitro pilot study was to analyse the adhesion behaviour of human osteoblasts and fibroblasts on polyether ether ketone (PEEK) when compared with titanium surfaces in an inflammatory environment under lipopolysaccharide (LPS) incubation. Scanning electron microscopy (SEM) images of primary human osteoblasts/fibroblasts on titanium/PEEK samples were created. The gene expression of the LPS-binding protein (LBP) and the LPS receptor (toll-like receptor 4; TLR4) was measured by real-time polymerase chain reaction (PCR). Immunocytochemistry was used to obtain evidence for the distribution of LBP/TLR4 at the protein level of the extra-cellular-matrix-binding protein vinculin and the actin cytoskeleton. SEM images revealed that the osteoblasts and fibroblasts on the PEEK surfaces had adhesion characteristics comparable to those of titanium. The osteoblasts contracted under LPS incubation and a significantly increased LBP gene expression were detected. This was discernible at the protein level on all the materials. Whereas no increase of TLR4 was detected with regard to mRNA concentrations, a considerable increase in the antibody reaction was detected on all the materials. As is the case with titanium, the colonisation of human osteoblasts and fibroblasts on PEEK samples is possible under pro-inflammatory environmental conditions and the cellular inflammation behaviour towards PEEK is lower than that of titanium.

scholarly journals Characterization of Phospholipase Activity of the Pseudomonas aeruginosa Type III Cytotoxin, ExoU

2005 ◽  
Vol 187 (3) ◽  
pp. 1192-1195 ◽  
Author(s):  
Hiromi Sato ◽  
Jimmy B. Feix ◽  
Cecilia J. Hillard ◽  
Dara W. Frank
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Substrate Specificity ◽  
Yeast Extract ◽  
Enzyme Activation ◽  
Phospholipase Activity ◽  
Eukaryotic Protein ◽  
Type Iii

ABSTRACT Recombinant ExoU (rExoU) and yeast extract were used to optimize an in vitro phospholipase assay as a basis for identifying the mechanism for enzyme activation and substrate specificity. Our results support a model in which a eukaryotic protein cofactor or complex facilitates the interaction of rExoU with phospholipid substrates.

scholarly journals Tribological Characterization of Polyether Ether Ketone (PEEK) Polymers Produced by Additive Manufacturing for Hydrodynamic Bearing Application

Lubricants ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 112
Author(s):  
Davide Massocchi ◽  
Giacomo Riboni ◽  
Nora Lecis ◽  
Steven Chatterton ◽  
Paolo Pennacchi
Keyword(s):  
Additive Manufacturing ◽  
Optical Microscope ◽  
Wear Volume ◽  
Coating Materials ◽  
Hydrodynamic Bearing ◽  
Polyether Ether Ketone ◽  
Strength Tests ◽  
Ether Ketone ◽  
Tribological Characterization

The coating materials commonly used in hydrodynamic bearings are the so-called “Babbitt metals” or “white metals”, as defined by ASTM B23-00. Their low Young’s modulus and yield point have encouraged researchers to find new coatings to overcome these limitations. In this paper, the friction and wear of PEEK are studied in a dry sliding environment (without lubrication) using a ball-on-disk tribometer and compared to those of Babbitt metal. Furthermore, the bond strength tests between PEEK and metals/alloys are evaluated. PEEK polymer samples were obtained from cylindrical rods, manufactured by an innovative process for polymer bonding on bearing surfaces, using additive manufacturing technology. The morphologies of the degraded surfaces were examined using a high-resolution metallurgical optical microscope (OM) and a scanning electron microscope (SEM). The coefficients of friction (CoF) were obtained under the alternating ball-on-disk dry tribometer. The results of the experimental activity show that PEEK polymers have CoFs of about 0.22 and 0.16 under the 1 and 5 N applied load, respectively. The CoF and wear volume loss results are reported and compared to the reference Babbitt coating.

scholarly journals Construction and Characterization of a Pseudomonas aeruginosa Mucoid Exopolysaccharide-Alginate Conjugate Vaccine

2003 ◽  
Vol 71 (7) ◽  
pp. 3875-3884 ◽  
Author(s):  
Christian Theilacker ◽  
Fadie T. Coleman ◽  
Simone Mueschenborn ◽  
Nicolas Llosa ◽  
Martha Grout ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Conjugate Vaccine ◽  
Significant Proportion ◽  
Vaccine Trial ◽  
Keyhole Limpet Hemocyanin ◽  
Opsonic Activity ◽  
Human Sera ◽  
Normal Human

ABSTRACT Deterioration of lung function in patients with cystic fibrosis (CF) is closely associated with chronic pulmonary infection with mucoid Pseudomonas aeruginosa. The mucoid exopolysaccharide (MEP) from P. aeruginosa has been shown to induce opsonic antibodies in mice that are protective against this chronic infection. MEP-specific opsonic antibodies are also commonly found in the sera of older CF patients lacking detectable P. aeruginosa infection. When used in a human vaccine trial, however, MEP only minimally induced opsonic antibodies. To evaluate whether conjugation of MEP to a carrier protein could improve its immunogenicity, we bound thiolated MEP to keyhole limpet hemocyanin (KLH) by using succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC) as a linker. In contrast to the native MEP polymer, the MEP-KLH conjugate vaccine induced high titers of MEP-specific immunoglobulin G (IgG) in C3H-HeN mice and in a rabbit. Sera from mice immunized with MEP-KLH conjugate, but not from animals immunized with comparable doses of native MEP, demonstrated opsonic killing activity. Vaccination with MEP-KLH conjugate induced opsonic antibodies broadly cross-reactive to heterologous mucoid strains of P. aeruginosa. Preexisting nonopsonic antibodies to MEP are found in normal human sera, including young CF patients, and their presence impedes the induction of opsonic antibodies. Induction of nonopsonic antibodies by either intraperitoneal injection of MEP or injection or feeding of the cross-reactive antigen, seaweed alginate, reduced the level of overall IgG elicited by follow-up immunization with the MEP-KLH conjugate. However, the opsonic activity was lower only in the sera of MEP-KLH conjugate-immunized mice with preexisting antibodies induced by MEP but not with antibodies induced by seaweed alginate. Immunization with MEP-KLH elicited a significant proportion of antibodies specific to epitopes involving O-acetate residues, and this subpopulation of antibodies mediated opsonic killing of mucoid P. aeruginosa in vitro. These results indicate that conjugation of MEP to KLH significantly enhances its immunogenicity and the elicitation of opsonic antibodies in mice and rabbits, that the conjugate induces opsonic antibodies in the presence of preexisting nonopsonic antibodies, and that opsonic antibodies to MEP are directed at epitopes that include acetate residues on the uronic acid polymer.

Sign in / Sign up

Export Citation Format

Share Document