The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
David S Jones - One of the best experts on this subject based on the ideXlab platform.
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preliminary investigations concerning the anti adherence properties of Polyhexamethylenebiguanide vantocil ib
International Journal of Pharmaceutics, 1995Co-Authors: David S JonesAbstract:Abstract The effect of Polyhexamethylenebiguanide (PHMB) on adherence of Candida albicans blastospores to human buccal epithelial cells (BEC) was examined in vitro. Treatments of either blastospores or BEC with PHMB (50 and 1000 μg ml −1 ) significantly reduced the number of adherent blastospores per BEC and increased the number of BEC devoid of blastospores.
Jordi Puiggalí - One of the best experts on this subject based on the ideXlab platform.
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Electrospun fibrous mats from a l-phenylalanine based poly(ester amide): Drug delivery and accelerated degradation by loading enzymes
Polymer Degradation and Stability, 2015Co-Authors: Sara K. Murase, Luis J. Del Valle, Ramaz Katsarava, Sophio Kobauri, Jordi PuiggalíAbstract:Abstract Fibrous mats from an α-amino acid based poly(ester amide) have been prepared due to the potential applications of this kind of polymers in the biomedical field thanks to the expected non-toxicity of their degradation products. Specifically, the electrospinning technique has been applied and both solution properties and operational parameters have been optimized to get continuous fibers in the micrometer range. Furthermore, fibrous mats have been loaded with biguanide compounds differing on molecular size but having a well-proved bactericide activity (i.e., chlorhexidine, CHX and Polyhexamethylenebiguanide, PHMB). The high solubility of the poly(ester amide) constituted by l -phenylalanine, adipic acid and 1,4-butanediol also allowed getting appropriate electrospinning conditions to incorporate degrading enzymes like α-chymotrypsin without significant denaturation. Degradability of fibrous mats has been evaluated in distinct enzymatic media (lipase, proteinase K and α-chymotrypsin) being found a similar behavior that contrasts with the significant differences detected when film samples were employed. An accelerated degradation was clearly found for fibrous mats loaded with α-chymotrypsin even when they were exposed to a non-enzymatic aqueous medium. Release of bactericide agents was evaluated and a specific delay was determined when the polymeric biguanide was employed. Nevertheless, PHMB showed a clearly enhanced activity. Biocompatibility of the new fibrous mats was verified being also determined an increase on the cell adhesion with respect to film samples as a consequence of the increased porosity.
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Polybiguanide (PHMB) loaded in PLA scaffolds displaying high hydrophobic, biocompatibility and antibacterial properties
Materials Science and Engineering: C, 2015Co-Authors: Elena Llorens, Silvia Calderón, Luis J. Del Valle, Jordi PuiggalíAbstract:Abstract Polyhexamethylenebiguanide hydrochloride (PHMB), a low molecular weight polymer related to chlorohexidine (CHX), is a well-known antibacterial agent. In this study, polylactide (PLA) nanofibers loaded with PHMB were produced by electrospinning to obtain 3D biodegradable scaffolds with antibacterial properties. PLA fibers loaded with CHX were used as control. The electrospun fibers were studied and analyzed by SEM, FTIR, DSC and contact angle measurements. PHMB and CHX release from loaded scaffolds was evaluated, as well as their antibacterial activity and biocompatibility. The results showed that the nanofibers became smoother and their diameter smaller with increasing the amount of loaded PHMB. This feature led to an increase of both surface roughness and hydrophobicity of the scaffold. PHMB release was highly dependent on the hydrophilicity of the medium and differed from that determined for CHX. Lastly, PHMB-loaded PLA scaffolds showed antibacterial properties since they inhibited adhesion and bacterial growth, and exhibited biocompatible characteristics for the adhesion and proliferation of both fibroblast and epithelial cell lines.
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New poly(ester urea) derived from L-leucine: electrospun scaffolds loaded with antibacterial drugs and enzymes.
Materials Science and Engineering: C, 2014Co-Authors: Angélica Díaz, Luis J. Del Valle, David Tugushi, Ramaz Katsarava, Jordi PuiggalíAbstract:Abstract Electrospun scaffolds from an amino acid containing poly(ester urea) (PEU) were developed as promising materials in the biomedical field and specifically in tissue engineering applications. The selected poly(ester urea) was obtained with a high yield and molecular weight by reaction of phosgene with a bis(α-aminoacyl)-α,ω-diol-diester monomer. The polymer having l -leucine, 1,6-hexanediol and carbonic acid units had a semicrystalline character and relatively high glass transition and melting temperatures. Furthermore it was highly soluble in most organic solvents, an interesting feature that facilitated the electrospinning process and the effective incorporation of drugs with bactericidal activity (e.g. biguanide derivatives such as clorhexidine and Polyhexamethylenebiguanide) and enzymes (e.g. α-chymotrypsin) that accelerated the degradation process. Continuous micro/nanofibers were obtained under a wide range of processing conditions, being diameters of electrospun fibers dependent on the drug and solvent used. Poly(ester urea) samples were degradable in media containing lipases and proteinases but the degradation rate was highly dependent on the surface area, being specifically greater for scaffolds with respect to films. The high hydrophobicity of new scaffolds had repercussions on enzymatic degradability since different weight loss rates were found depending on how samples were exposed to the medium (e.g. forced or non-forced immersion). New scaffolds were biocompatible, as demonstrated by adhesion and proliferation assays performed with fibroblast and epithelial cells.
Mark E. Berrang - One of the best experts on this subject based on the ideXlab platform.
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Bactericidal Effect of Several Chemicals on Hatching Eggs Inoculated with Salmonella serovar Typhimurium
The Journal of Applied Poultry Research, 2007Co-Authors: L. J. Richardson, Mark E. Berrang, R. J. Buhr, M. T. Musgrove, W. BrightAbstract:Abstract Breeder flocks and commercial hatcheries represent an early contamination point for Salmonella entry into commercial integrated poultry operations. Utilizing effective antimicrobial treatments for hatching eggs is a critical part of reducing the incidence of Salmonella-colonized chicks on the farm. The objective of this study was to evaluate the bactericidal effect of several chemicals on Salmonella-contaminated hatching eggs. Four replications (n = 10/treatment per replicate) were conducted to determine the efficacy of 7 commercially available compounds. The compounds tested were as follows: 1) hydrogen peroxide, 2) water-oil emulsion droplets stabilized by detergent, 3) peroxyacetic acid, 4) 4 quaternary ammonium compounds attached to a polymer, 5) 2 quaternary ammonium compounds, 1 biguanide compound and bronopol attached to a polymer, 6) N-alkyl dimethyl benzyl ammonium chloride and stabilized urea, and 7) Polyhexamethylenebiguanide hydrochloride. A naladixic acid-resistant Salmonella serovar Typhimurium was inoculated (103 cfu/mL) onto fertile hatching eggs by drip-inoculation. Controls included a positive control (no spray application) and a water control (spray containing water to take into account rinsing effects). Compounds 5 and 7 had a 100% reduction, and both of these chemicals included a biguanide. Compounds 4 and 3 were also effective with a 95 and 93.5% reduction, respectively. Compounds 6 and 2 were the least effective of all chemicals, with a reduction of 47.5 and 40%, respectively. Hydrogen peroxide (compound 1), which has been used by the poultry industry, had a 70% reduction, and the water control produced a 10% reduction due to the rinsing effect. Several antimicrobials tested were more effective than hydrogen peroxide. More detailed studies will be required to adequately evaluate these antimicrobials.
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BACTERICIDAL TREATMENT OF HATCHING EGGS III: EFFECT OF ORGANIC CONTAMINANTS ON EFFICACY OF EGG SANITIZERS
The Journal of Applied Poultry Research, 2001Co-Authors: J. S. Bailey, Mark E. BerrangAbstract:SUMMARY The effectiveness of three sanitizers in killing Salmonella during room temperature storage with and without contaminating feces, egg, or chicken rinse for 48 h was tested. Uncontaminated sanitizers were tested, as were 50-mL solutions of 0.035% Polyhexamethylenebiguanide hydrochloride (PHMB), 0.39% (1:256) Tektrol, and 1.4% H2O2, which were contaminated with 10 mL of a feces slurry, 10 mL of mixed egg, or 10 mL of chicken rinse. Each container was inoculated with approximately 1,000 cells of S. typhimurium and cultured after 1 and 5 min. After 24 and 48 h of storage, each original container was reinoculated and assayed for the new inoculum at 1 and 5 min postinoculation. Complete eradication of Salmonella was noted after 1 or 5 min exposure to fresh or stored uncontaminated sanitizer solutions. Tektrol became less active against Salmonella when contaminated with egg and stored for 24 h or more. However, feces or chicken rinse did not interfere with the activity of Tektrol. Hydrogen peroxide deteriorated most with storage with chicken feces and to a lesser extent chicken rinse. PHMB lost efficacy when exposed to chicken feces for 24 h or more, but was not affected by the other contaminants.
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Bactericidal Treatment of Hatching Eggs I. Chemical Immersion Treatments and Salmonella
The Journal of Applied Poultry Research, 1998Co-Authors: J. S. Bailey, Mark E. BerrangAbstract:Abstract Breeder flocks and commercial hatcheries represent the earliest and probably the most critical control points for salmonellae entry into commercial integrated poultry operations. Effective chemical treatment of hatching eggs may also be a necessary part of reducing the presence of salmonellae on processed broiler carcasses. This study evaluated the immersion of artificially inoculated eggs into three chemicals: phenol, hydrogen peroxide (H2O2), and Polyhexamethylenebiguanide hydrochloride (PHMB) following various inoculum drying times of 1 min, 5 min, 4 hr, and 24 hr. Reductions in Salmonella-positive eggs for the various chemicals as compared to the water-treated controls were as follows: 1) 0.78% phenol: 80% reduction at 1 min, 0% reduction if the egg was treated 24 hr after contamination; 2) 2.0% H2O2: 85% reduction at 1 min, 25% reduction at 24 hr; 3) 0.05% PHMB: 93% reduction at 1 min, 12% reduction at 24 hr. These data demonstrate that chemical treatments do not consistently kill all Salmonella on or in eggshells and that what effectiveness they have appears to diminish as the amount of time between contamination and treatment increases.
Luis J. Del Valle - One of the best experts on this subject based on the ideXlab platform.
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Electrospun fibrous mats from a l-phenylalanine based poly(ester amide): Drug delivery and accelerated degradation by loading enzymes
Polymer Degradation and Stability, 2015Co-Authors: Sara K. Murase, Luis J. Del Valle, Ramaz Katsarava, Sophio Kobauri, Jordi PuiggalíAbstract:Abstract Fibrous mats from an α-amino acid based poly(ester amide) have been prepared due to the potential applications of this kind of polymers in the biomedical field thanks to the expected non-toxicity of their degradation products. Specifically, the electrospinning technique has been applied and both solution properties and operational parameters have been optimized to get continuous fibers in the micrometer range. Furthermore, fibrous mats have been loaded with biguanide compounds differing on molecular size but having a well-proved bactericide activity (i.e., chlorhexidine, CHX and Polyhexamethylenebiguanide, PHMB). The high solubility of the poly(ester amide) constituted by l -phenylalanine, adipic acid and 1,4-butanediol also allowed getting appropriate electrospinning conditions to incorporate degrading enzymes like α-chymotrypsin without significant denaturation. Degradability of fibrous mats has been evaluated in distinct enzymatic media (lipase, proteinase K and α-chymotrypsin) being found a similar behavior that contrasts with the significant differences detected when film samples were employed. An accelerated degradation was clearly found for fibrous mats loaded with α-chymotrypsin even when they were exposed to a non-enzymatic aqueous medium. Release of bactericide agents was evaluated and a specific delay was determined when the polymeric biguanide was employed. Nevertheless, PHMB showed a clearly enhanced activity. Biocompatibility of the new fibrous mats was verified being also determined an increase on the cell adhesion with respect to film samples as a consequence of the increased porosity.
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Polybiguanide (PHMB) loaded in PLA scaffolds displaying high hydrophobic, biocompatibility and antibacterial properties
Materials Science and Engineering: C, 2015Co-Authors: Elena Llorens, Silvia Calderón, Luis J. Del Valle, Jordi PuiggalíAbstract:Abstract Polyhexamethylenebiguanide hydrochloride (PHMB), a low molecular weight polymer related to chlorohexidine (CHX), is a well-known antibacterial agent. In this study, polylactide (PLA) nanofibers loaded with PHMB were produced by electrospinning to obtain 3D biodegradable scaffolds with antibacterial properties. PLA fibers loaded with CHX were used as control. The electrospun fibers were studied and analyzed by SEM, FTIR, DSC and contact angle measurements. PHMB and CHX release from loaded scaffolds was evaluated, as well as their antibacterial activity and biocompatibility. The results showed that the nanofibers became smoother and their diameter smaller with increasing the amount of loaded PHMB. This feature led to an increase of both surface roughness and hydrophobicity of the scaffold. PHMB release was highly dependent on the hydrophilicity of the medium and differed from that determined for CHX. Lastly, PHMB-loaded PLA scaffolds showed antibacterial properties since they inhibited adhesion and bacterial growth, and exhibited biocompatible characteristics for the adhesion and proliferation of both fibroblast and epithelial cell lines.
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New poly(ester urea) derived from L-leucine: electrospun scaffolds loaded with antibacterial drugs and enzymes.
Materials Science and Engineering: C, 2014Co-Authors: Angélica Díaz, Luis J. Del Valle, David Tugushi, Ramaz Katsarava, Jordi PuiggalíAbstract:Abstract Electrospun scaffolds from an amino acid containing poly(ester urea) (PEU) were developed as promising materials in the biomedical field and specifically in tissue engineering applications. The selected poly(ester urea) was obtained with a high yield and molecular weight by reaction of phosgene with a bis(α-aminoacyl)-α,ω-diol-diester monomer. The polymer having l -leucine, 1,6-hexanediol and carbonic acid units had a semicrystalline character and relatively high glass transition and melting temperatures. Furthermore it was highly soluble in most organic solvents, an interesting feature that facilitated the electrospinning process and the effective incorporation of drugs with bactericidal activity (e.g. biguanide derivatives such as clorhexidine and Polyhexamethylenebiguanide) and enzymes (e.g. α-chymotrypsin) that accelerated the degradation process. Continuous micro/nanofibers were obtained under a wide range of processing conditions, being diameters of electrospun fibers dependent on the drug and solvent used. Poly(ester urea) samples were degradable in media containing lipases and proteinases but the degradation rate was highly dependent on the surface area, being specifically greater for scaffolds with respect to films. The high hydrophobicity of new scaffolds had repercussions on enzymatic degradability since different weight loss rates were found depending on how samples were exposed to the medium (e.g. forced or non-forced immersion). New scaffolds were biocompatible, as demonstrated by adhesion and proliferation assays performed with fibroblast and epithelial cells.
J. S. Bailey - One of the best experts on this subject based on the ideXlab platform.
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BACTERICIDAL TREATMENT OF HATCHING EGGS III: EFFECT OF ORGANIC CONTAMINANTS ON EFFICACY OF EGG SANITIZERS
The Journal of Applied Poultry Research, 2001Co-Authors: J. S. Bailey, Mark E. BerrangAbstract:SUMMARY The effectiveness of three sanitizers in killing Salmonella during room temperature storage with and without contaminating feces, egg, or chicken rinse for 48 h was tested. Uncontaminated sanitizers were tested, as were 50-mL solutions of 0.035% Polyhexamethylenebiguanide hydrochloride (PHMB), 0.39% (1:256) Tektrol, and 1.4% H2O2, which were contaminated with 10 mL of a feces slurry, 10 mL of mixed egg, or 10 mL of chicken rinse. Each container was inoculated with approximately 1,000 cells of S. typhimurium and cultured after 1 and 5 min. After 24 and 48 h of storage, each original container was reinoculated and assayed for the new inoculum at 1 and 5 min postinoculation. Complete eradication of Salmonella was noted after 1 or 5 min exposure to fresh or stored uncontaminated sanitizer solutions. Tektrol became less active against Salmonella when contaminated with egg and stored for 24 h or more. However, feces or chicken rinse did not interfere with the activity of Tektrol. Hydrogen peroxide deteriorated most with storage with chicken feces and to a lesser extent chicken rinse. PHMB lost efficacy when exposed to chicken feces for 24 h or more, but was not affected by the other contaminants.
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Bactericidal Treatment of Hatching Eggs I. Chemical Immersion Treatments and Salmonella
The Journal of Applied Poultry Research, 1998Co-Authors: J. S. Bailey, Mark E. BerrangAbstract:Abstract Breeder flocks and commercial hatcheries represent the earliest and probably the most critical control points for salmonellae entry into commercial integrated poultry operations. Effective chemical treatment of hatching eggs may also be a necessary part of reducing the presence of salmonellae on processed broiler carcasses. This study evaluated the immersion of artificially inoculated eggs into three chemicals: phenol, hydrogen peroxide (H2O2), and Polyhexamethylenebiguanide hydrochloride (PHMB) following various inoculum drying times of 1 min, 5 min, 4 hr, and 24 hr. Reductions in Salmonella-positive eggs for the various chemicals as compared to the water-treated controls were as follows: 1) 0.78% phenol: 80% reduction at 1 min, 0% reduction if the egg was treated 24 hr after contamination; 2) 2.0% H2O2: 85% reduction at 1 min, 25% reduction at 24 hr; 3) 0.05% PHMB: 93% reduction at 1 min, 12% reduction at 24 hr. These data demonstrate that chemical treatments do not consistently kill all Salmonella on or in eggshells and that what effectiveness they have appears to diminish as the amount of time between contamination and treatment increases.