The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Michael J Solomon - One of the best experts on this subject based on the ideXlab platform.
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flexible microfluidic device for mechanical property characterization of soft viscoelastic solids such as Bacterial Biofilms
2009Co-Authors: Danial N Hohne, John G Younger, Michael J SolomonAbstract:We introduce a flexible microfluidic device to characterize the mechanical properties of soft viscoelastic solids such as Bacterial Biofilms. In the device, stress is imposed on a test specimen by ...
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flexible microfluidic device for mechanical property characterization of soft viscoelastic solids such as Bacterial Biofilms
2009Co-Authors: Danial N Hohne, John G Younger, Michael J SolomonAbstract:We introduce a flexible microfluidic device to characterize the mechanical properties of soft viscoelastic solids such as Bacterial Biofilms. In the device, stress is imposed on a test specimen by the application of a fixed pressure to a thin, flexible poly(dimethyl siloxane) (PDMS) membrane that is in contact with the specimen. The stress is applied by pressurizing a microfabricated air channel located above the test area. The strain resulting from the applied stress is quantified by measuring the membrane deflection with a confocal laser scanning microscope. The deflection is governed by the viscoelastic properties of the PDMS membrane and of the test specimen. The relative contributions of the membrane and test material to the measured deformation are quantified by comparing a finite element analysis with an independent (control) measurement of the PDMS membrane mechanical properties. The flexible microfluidic rheometer was used to characterize both the steady-state elastic modulus and the transient strain recoil of two soft materials: gellan gums and Bacterial Biofilms. The measured linear elastic moduli and viscoelastic relaxation times of gellan gum solutions were in good agreement with the results of conventional mechanical rheometry. The linear Young's moduli of Biofilms of Staphylococcus epidermidis and Klebsiella pneumoniae, which could not be measured using conventional methods, were found to be 3.2 and 1.1 kPa, respectively, and the relaxation time of the S. epidermidis biofilm was 13.8 s. Additionally, strain hardening was observed in all the Biofilms studied. Finally, design parameters and detection limits of the method show that the device is capable of characterizing soft viscoelastic solids with elastic moduli in the range of 102-105 Pa. The flexible microfluidic rheometer addresses the need for mechanical property characterization of soft viscoelastic solids common in fields such as biomaterials, food, and consumer products. It requires only 200 pL of the test specimen.
Danial N Hohne - One of the best experts on this subject based on the ideXlab platform.
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flexible microfluidic device for mechanical property characterization of soft viscoelastic solids such as Bacterial Biofilms
2009Co-Authors: Danial N Hohne, John G Younger, Michael J SolomonAbstract:We introduce a flexible microfluidic device to characterize the mechanical properties of soft viscoelastic solids such as Bacterial Biofilms. In the device, stress is imposed on a test specimen by ...
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flexible microfluidic device for mechanical property characterization of soft viscoelastic solids such as Bacterial Biofilms
2009Co-Authors: Danial N Hohne, John G Younger, Michael J SolomonAbstract:We introduce a flexible microfluidic device to characterize the mechanical properties of soft viscoelastic solids such as Bacterial Biofilms. In the device, stress is imposed on a test specimen by the application of a fixed pressure to a thin, flexible poly(dimethyl siloxane) (PDMS) membrane that is in contact with the specimen. The stress is applied by pressurizing a microfabricated air channel located above the test area. The strain resulting from the applied stress is quantified by measuring the membrane deflection with a confocal laser scanning microscope. The deflection is governed by the viscoelastic properties of the PDMS membrane and of the test specimen. The relative contributions of the membrane and test material to the measured deformation are quantified by comparing a finite element analysis with an independent (control) measurement of the PDMS membrane mechanical properties. The flexible microfluidic rheometer was used to characterize both the steady-state elastic modulus and the transient strain recoil of two soft materials: gellan gums and Bacterial Biofilms. The measured linear elastic moduli and viscoelastic relaxation times of gellan gum solutions were in good agreement with the results of conventional mechanical rheometry. The linear Young's moduli of Biofilms of Staphylococcus epidermidis and Klebsiella pneumoniae, which could not be measured using conventional methods, were found to be 3.2 and 1.1 kPa, respectively, and the relaxation time of the S. epidermidis biofilm was 13.8 s. Additionally, strain hardening was observed in all the Biofilms studied. Finally, design parameters and detection limits of the method show that the device is capable of characterizing soft viscoelastic solids with elastic moduli in the range of 102-105 Pa. The flexible microfluidic rheometer addresses the need for mechanical property characterization of soft viscoelastic solids common in fields such as biomaterials, food, and consumer products. It requires only 200 pL of the test specimen.
Feng Wan - One of the best experts on this subject based on the ideXlab platform.
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synthesis of carbon quantum dot poly lactic co glycolic acid hybrid nanoparticles for chemo photothermal therapy against Bacterial Biofilms
2020Co-Authors: Zheng Huang, Sylvia Natalie Klodzinska, Tongchang Zhou, Yuan Yuan, Tao Zheng, Claus Sternberg, Hanne Morck Nielsen, Yi Sun, Feng WanAbstract:Bacterial biofilm represents a protected mode of Bacterial growth that significantly enhances the resistance to antibiotics. Poly lactic-co-glycolic acid (PLGA)-based nanoparticle delivery systems have been intensively investigated to combat the Bacterial Biofilms-associated infections. However, some drawbacks associated with current PLGA-based nanoformulations (e.g. the relatively low drug loading capability, premature burst release and/or incapability of on-demand release of cargos at the site of action) restrict the transition from the lab research to the clinical applications. One potent strategy to overcome the above-mentioned limitations is exploiting the unique properties of carbon quantum dots (CQDs) and combining CQDs with the conventional PLGA nanoparticles. In the present study, the CQDs were innovatively incorporated into PLGA nanoparticles by using a microfluidic method. The resulting CQD-PLGA hybrid nanoparticles presented good loading capability of azithromycin (a macrolide antibiotic, AZI) and tobramycin (an aminoglycoside antibiotic, TOB), and stimuli-responsive release of the cargos upon laser irradiation. Consequently, AZI-loaded CQD-PLGA hybrid nanoparticles showed chemo-photothermally synergistic anti-biofilm effects against P. aeruginosa Biofilms. Additionally, the CQD-PLGA hybrid nanoparticles demonstrated good biocompatibility with the eukaryotic cells. Overall, the proof-of-concept of CQD-PLGA hybrid nanoparticles may open a new possibility in chemo-photothermal therapy against Bacterial Biofilms.
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Lipid Shell-Enveloped Polymeric Nanoparticles with High Integrity of Lipid Shells Improve Mucus Penetration and Interaction with Cystic Fibrosis-Related Bacterial Biofilms
2018Co-Authors: Feng Wan, Tommy Nylander, Sylvia Natalie Klodzinska, Camilla Foged, Mingshi Yang, Stefania G. Baldursdottir, Hanne M. NielsenAbstract:Nanoparticle (NP) mediated drug delivery into viscous biomatrices, e.g., mucus and Bacterial Biofilms, is challenging. Lipid shell-enveloped polymeric NPs (Lipid@NPs), composed of a polymeric NP core coated with a lipid shell, represent a promising alternative to the current delivery systems. Here, we describe the facile methods to prepare Lipid@NPs with high integrity of lipid shells and demonstrate the potential of Lipid@NPs in an effective mucus penetration and interaction with cystic fibrosis-related Bacterial Biofilms. Lipid shell-enveloped polystyrene NPs with high integrity of lipid shells (cLipid@PSNPs) were prepared by using an electrostatically mediated layer-by-layer approach, where the model polystyrene NPs (PSNPs) were first modified with positively charged poly-l-lysine (PLL) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), followed by subsequent fusion with zwitterionic, PEGylated small unilamellar vesicles (SUVs). The interaction of the PSNPs with SUVs was significantly enhanced by modifying the PSNPs with PLL and DOTAP, which eventually resulted in the formation of cLipid@PSNPs, i.e., Lipid@PLL-PSNPs and Lipid@DOTAP-PSNPs. Improved mucus-penetrating property of cLipid@PSNPs was demonstrated by quartz crystal microbalance with dissipation monitoring measurements. Furthermore, fluorescence resonance energy transfer measurements showed that the interaction of the cLipid@PSNPs with Bacterial Biofilms was significantly promoted. In conclusion, we prepared cLipid@PSNPs via an electrostatically mediated layer-by-layer approach. Our results suggest that the integrity of the lipid envelopes is crucial for enabling the diffusion of Lipid@PSNPs into the mucus layer and promoting the interaction of Lipid@PSNPs with a Bacterial biofilm
Pilar García - One of the best experts on this subject based on the ideXlab platform.
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Analysis of Different Parameters Affecting Diffusion, Propagation and Survival of Staphylophages in Bacterial Biofilms
2018Co-Authors: Silvia González, Diana Gutiérrez, Ana Rodríguez, Lucía Fernández, Ana Belén Campelo, Pilar GarcíaAbstract:The elimination of Bacterial Biofilms remains a major challenge due to their recalcitrant nature. Bacteriophages, viruses that infect bacteria, have been gaining increasing attention as biofilm control agents. However, the development of a successful phage-based strategy requires in-depth analysis of different parameters. It is particularly important to determine the ability of a given phage to diffuse, propagate and remain viable within the complex biofilm structure. Here, we examine some of these properties for two staphylophages, vB_SauM_phiIPLA-RODI and vB_SepM_phiIPLA-C1C. Both Staphylococcus aureus and Staphylococcus epidermidis are important opportunistic pathogens that readily form Biofilms on a wide array of biotic and abiotic surfaces. Our results confirmed that both phages could penetrate through Biofilms formed by several Bacterial strains with varying degrees of susceptibility to the viruses and biofilm-forming abilities. However, phage penetration differed depending on the specific bacterium or combination of bacteria. The data presented here suggest that the factors determining the diffusion rate of phages in Biofilms include the amount of attached biomass, susceptibility of the strain, initial phage titer, phage entrapment in the extracellular matrix, and phage inactivation. This information will help to further characterize phage-bacteria interactions within biofilm communities and will be valuable for the development of antistaphylococcal products based on these phages
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Bacteriophages as weapons against Bacterial Biofilms in the food industry
2016Co-Authors: Diana Gutiérrez, Lorena Rodríguez-rubio, Beatriz Martínez, Ana Rodríguez, Pilar GarcíaAbstract:Microbiological contamination in the food industry is often attributed to the presence of Biofilms in processing plants. Bacterial Biofilms are complex communities of bacteria attached to a surface and surrounded by an extracellular polymeric material. Their extreme resistance to cleaning and disinfecting processes is related to a unique organization, which implies a differential Bacterial growth and gene expression inside the biofilm. The impact of Biofilms on health, and the economic consequences, has promoted the development of different approaches to control or remove biofilm formation. Recently, successful results in phage therapy have boosted new research in bacteriophages and phage lytic proteins for biofilm eradication. In this regard, this review examines the environmental factors that determine biofilm development in food-processing equipment. In addition, future perspectives for the use of bacteriophage-derived tools as disinfectants are discussed.
John G Younger - One of the best experts on this subject based on the ideXlab platform.
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flexible microfluidic device for mechanical property characterization of soft viscoelastic solids such as Bacterial Biofilms
2009Co-Authors: Danial N Hohne, John G Younger, Michael J SolomonAbstract:We introduce a flexible microfluidic device to characterize the mechanical properties of soft viscoelastic solids such as Bacterial Biofilms. In the device, stress is imposed on a test specimen by ...
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flexible microfluidic device for mechanical property characterization of soft viscoelastic solids such as Bacterial Biofilms
2009Co-Authors: Danial N Hohne, John G Younger, Michael J SolomonAbstract:We introduce a flexible microfluidic device to characterize the mechanical properties of soft viscoelastic solids such as Bacterial Biofilms. In the device, stress is imposed on a test specimen by the application of a fixed pressure to a thin, flexible poly(dimethyl siloxane) (PDMS) membrane that is in contact with the specimen. The stress is applied by pressurizing a microfabricated air channel located above the test area. The strain resulting from the applied stress is quantified by measuring the membrane deflection with a confocal laser scanning microscope. The deflection is governed by the viscoelastic properties of the PDMS membrane and of the test specimen. The relative contributions of the membrane and test material to the measured deformation are quantified by comparing a finite element analysis with an independent (control) measurement of the PDMS membrane mechanical properties. The flexible microfluidic rheometer was used to characterize both the steady-state elastic modulus and the transient strain recoil of two soft materials: gellan gums and Bacterial Biofilms. The measured linear elastic moduli and viscoelastic relaxation times of gellan gum solutions were in good agreement with the results of conventional mechanical rheometry. The linear Young's moduli of Biofilms of Staphylococcus epidermidis and Klebsiella pneumoniae, which could not be measured using conventional methods, were found to be 3.2 and 1.1 kPa, respectively, and the relaxation time of the S. epidermidis biofilm was 13.8 s. Additionally, strain hardening was observed in all the Biofilms studied. Finally, design parameters and detection limits of the method show that the device is capable of characterizing soft viscoelastic solids with elastic moduli in the range of 102-105 Pa. The flexible microfluidic rheometer addresses the need for mechanical property characterization of soft viscoelastic solids common in fields such as biomaterials, food, and consumer products. It requires only 200 pL of the test specimen.