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Pritchard MF, Powell LC, Adams JYM, Menzies G, Khan S, Tøndervik A, Sletta H, Aarstad O, Skjåk-Bræk G, McKenna S, Buurma NJ, Farnell DJJ, Rye PD, Hill KE, Thomas DW. Structure-Activity Relationships of Low Molecular Weight Alginate Oligosaccharide Therapy against Pseudomonas aeruginosa. Biomolecules 2023; 13:1366. [PMID: 37759766 PMCID: PMC10527064 DOI: 10.3390/biom13091366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/26/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023] Open
Abstract
Low molecular weight alginate oligosaccharides have been shown to exhibit anti-microbial activity against a range of multi-drug resistant bacteria, including Pseudomonas aeruginosa. Previous studies suggested that the disruption of calcium (Ca2+)-DNA binding within bacterial biofilms and dysregulation of quorum sensing (QS) were key factors in these observed effects. To further investigate the contribution of Ca2+ binding, G-block (OligoG) and M-block alginate oligosaccharides (OligoM) with comparable average size DPn 19 but contrasting Ca2+ binding properties were prepared. Fourier-transform infrared spectroscopy demonstrated prolonged binding of alginate oligosaccharides to the pseudomonal cell membrane even after hydrodynamic shear treatment. Molecular dynamics simulations and isothermal titration calorimetry revealed that OligoG exhibited stronger interactions with bacterial LPS than OligoM, although this difference was not mirrored by differential reductions in bacterial growth. While confocal laser scanning microscopy showed that both agents demonstrated similar dose-dependent reductions in biofilm formation, OligoG exhibited a stronger QS inhibitory effect and increased potentiation of the antibiotic azithromycin in minimum inhibitory concentration and biofilm assays. This study demonstrates that the anti-microbial effects of alginate oligosaccharides are not purely influenced by Ca2+-dependent processes but also by electrostatic interactions that are common to both G-block and M-block structures.
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Affiliation(s)
- Manon F. Pritchard
- Advanced Therapies Group, School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (L.C.P.); (J.Y.M.A.); (S.K.); (S.M.); (D.J.J.F.); (K.E.H.); (D.W.T.)
| | - Lydia C. Powell
- Advanced Therapies Group, School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (L.C.P.); (J.Y.M.A.); (S.K.); (S.M.); (D.J.J.F.); (K.E.H.); (D.W.T.)
- Microbiology and Infectious Disease Group, Swansea University Medical School, Swansea SA2 8PP, UK
| | - Jennifer Y. M. Adams
- Advanced Therapies Group, School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (L.C.P.); (J.Y.M.A.); (S.K.); (S.M.); (D.J.J.F.); (K.E.H.); (D.W.T.)
| | - Georgina Menzies
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK;
| | - Saira Khan
- Advanced Therapies Group, School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (L.C.P.); (J.Y.M.A.); (S.K.); (S.M.); (D.J.J.F.); (K.E.H.); (D.W.T.)
| | - Anne Tøndervik
- Department of Bioprocess Technology, SINTEF Materials and Chemistry, N-7465 Trondheim, Norway; (A.T.); (H.S.)
| | - Håvard Sletta
- Department of Bioprocess Technology, SINTEF Materials and Chemistry, N-7465 Trondheim, Norway; (A.T.); (H.S.)
| | - Olav Aarstad
- Department of Biotechnology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway; (O.A.); (G.S.-B.)
| | - Gudmund Skjåk-Bræk
- Department of Biotechnology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway; (O.A.); (G.S.-B.)
| | - Stephen McKenna
- Advanced Therapies Group, School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (L.C.P.); (J.Y.M.A.); (S.K.); (S.M.); (D.J.J.F.); (K.E.H.); (D.W.T.)
| | - Niklaas J. Buurma
- Physical Organic Chemistry Centre, School of Chemistry, Cardiff University, Cardiff CF10 3AT, UK;
| | - Damian J. J. Farnell
- Advanced Therapies Group, School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (L.C.P.); (J.Y.M.A.); (S.K.); (S.M.); (D.J.J.F.); (K.E.H.); (D.W.T.)
| | - Philip D. Rye
- AlgiPharma AS, Industriveien 33, N-1337 Sandvika, Norway;
| | - Katja E. Hill
- Advanced Therapies Group, School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (L.C.P.); (J.Y.M.A.); (S.K.); (S.M.); (D.J.J.F.); (K.E.H.); (D.W.T.)
| | - David W. Thomas
- Advanced Therapies Group, School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK; (L.C.P.); (J.Y.M.A.); (S.K.); (S.M.); (D.J.J.F.); (K.E.H.); (D.W.T.)
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Xue W, Pritchard MF, Khan S, Powell LC, Stokniene J, Wu J, Claydon N, Reddell P, Thomas DW, Hill KE. Defining in vitro topical antimicrobial and antibiofilm activity of epoxy-tigliane structures against oral pathogens. J Oral Microbiol 2023; 15:2241326. [PMID: 37534218 PMCID: PMC10392292 DOI: 10.1080/20002297.2023.2241326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/04/2023] [Accepted: 07/20/2023] [Indexed: 08/04/2023] Open
Abstract
Background Peri-implantitis has become an inexorable clinical challenge in implantology. Topical immunomodulatory epoxy-tiglianes (EBCs), derived from the Queensland blushwood tree, which induce remodeling and resolve dermal infection via induction of the inflammasome and biofilm disruption, may offer a novel therapeutic approach. Design In vitro antimicrobial activity of EBC structures (EBC-46, EBC-1013 and EBC-147) against Streptococcus mutans, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis in minimum inhibitory concentration, growth curve and permeabilization assays were determined. Antibiofilm activity was assessed using minimum biofilm eradication concentration (MBEC) experiments. Biofilm formation and disruption assays were analyzed using confocal laser scanning microscopy, scanning electron microscopy and direct plate counting. Results The observed antimicrobial efficacy of the tested compounds (EBC-1013 > EBC-46 > EBC-147) was directly related to significant membrane permeabilization and growth inhibition (p < 0.05) against planktonic S. mutans and P. gingivalis. Antibiofilm activity was evident in MBEC assays, with S. mutans biofilm formation assays revealing significantly lower biomass volume and increased DEAD:LIVE cell ratio observed for EBC-1013 (p < 0.05). Furthermore, biofilm disruption assays on titanium discs induced significant biofilm disruption in S. mutans and P. gingivalis (p < 0.05). Conclusions EBC-1013 is a safe, semi-synthetic, compound, demonstrating clear antimicrobial biofilm disruption potential in peri-implantitis.
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Affiliation(s)
- Wenya Xue
- Advanced Therapies Group, Cardiff School of Dentistry, Heath Park, Cardiff University, Cardiff, UK
| | - Manon F. Pritchard
- Advanced Therapies Group, Cardiff School of Dentistry, Heath Park, Cardiff University, Cardiff, UK
| | - Saira Khan
- Advanced Therapies Group, Cardiff School of Dentistry, Heath Park, Cardiff University, Cardiff, UK
| | - Lydia C. Powell
- Microbiology and Infectious Disease Group, Swansea University Medical School, Swansea, UK
| | - Joana Stokniene
- Advanced Therapies Group, Cardiff School of Dentistry, Heath Park, Cardiff University, Cardiff, UK
| | - Jingxiang Wu
- Advanced Therapies Group, Cardiff School of Dentistry, Heath Park, Cardiff University, Cardiff, UK
| | - Nicholas Claydon
- Advanced Therapies Group, Cardiff School of Dentistry, Heath Park, Cardiff University, Cardiff, UK
| | - Paul Reddell
- QBiotics Group Limited, Yungaburra, Queensland, Australia
| | - David W. Thomas
- Advanced Therapies Group, Cardiff School of Dentistry, Heath Park, Cardiff University, Cardiff, UK
| | - Katja E. Hill
- Advanced Therapies Group, Cardiff School of Dentistry, Heath Park, Cardiff University, Cardiff, UK
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Powell LC, Adams JYM, Quoraishi S, Py C, Oger A, Gazze SA, Francis LW, von Ruhland C, Owens D, Rye PD, Hill KE, Pritchard MF, Thomas DW. Alginate oligosaccharides enhance the antifungal activity of nystatin against candidal biofilms. Front Cell Infect Microbiol 2023; 13:1122340. [PMID: 36798083 PMCID: PMC9927220 DOI: 10.3389/fcimb.2023.1122340] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 01/11/2023] [Indexed: 02/04/2023] Open
Abstract
Background The increasing prevalence of invasive fungal infections in immuno-compromised patients is a considerable cause of morbidity and mortality. With the rapid emergence of antifungal resistance and an inadequate pipeline of new therapies, novel treatment strategies are now urgently required. Methods The antifungal activity of the alginate oligosaccharide OligoG in conjunction with nystatin was tested against a range of Candida spp. (C. albicans, C. glabrata, C. parapsilosis, C. auris, C. tropicalis and C. dubliniensis), in both planktonic and biofilm assays, to determine its potential clinical utility to enhance the treatment of candidal infections. The effect of OligoG (0-6%) ± nystatin on Candida spp. was examined in minimum inhibitory concentration (MIC) and growth curve assays. Antifungal effects of OligoG and nystatin treatment on biofilm formation and disruption were characterized using confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and ATP cellular viability assays. Effects on the cell membrane were determined using permeability assays and transmission electron microscopy (TEM). Results MIC and growth curve assays demonstrated the synergistic effects of OligoG (0-6%) with nystatin, resulting in an up to 32-fold reduction in MIC, and a significant reduction in the growth of C. parapsilosis and C. auris (minimum significant difference = 0.2 and 0.12 respectively). CLSM and SEM imaging demonstrated that the combination treatment of OligoG (4%) with nystatin (1 µg/ml) resulted in significant inhibition of candidal biofilm formation on glass and clinical grade silicone surfaces (p < 0.001), with increased cell death (p < 0.0001). The ATP biofilm disruption assay demonstrated a significant reduction in cell viability with OligoG (4%) alone and the combined OligoG/nystatin (MIC value) treatment (p < 0.04) for all Candida strains tested. TEM studies revealed the combined OligoG/nystatin treatment induced structural reorganization of the Candida cell membrane, with increased permeability when compared to the untreated control (p < 0.001). Conclusions Antimicrobial synergy between OligoG and nystatin against Candida spp. highlights the potential utility of this combination therapy in the prevention and topical treatment of candidal biofilm infections, to overcome the inherent tolerance of biofilm structures to antifungal agents.
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Affiliation(s)
- Lydia C. Powell
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff, United Kingdom
- Microbiology and Infectious Disease group, Swansea University Medical School, Swansea, United Kingdom
- *Correspondence: Lydia C. Powell,
| | - Jennifer Y. M. Adams
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff, United Kingdom
| | - Sadik Quoraishi
- Otolaryngology Department, New Cross Hospital, Wolverhampton, United Kingdom
| | - Charlène Py
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff, United Kingdom
- School of Engineering, University of Angers, Angers, France
| | - Anaϊs Oger
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff, United Kingdom
- School of Engineering, University of Angers, Angers, France
| | - Salvatore A. Gazze
- Centre for Nanohealth, Swansea University Medical School, Swansea, United Kingdom
| | - Lewis W. Francis
- Centre for Nanohealth, Swansea University Medical School, Swansea, United Kingdom
| | - Christopher von Ruhland
- Central Biotechnology Services, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - David Owens
- Head and Neck Directorate, University Hospital of Wales, Cardiff, United Kingdom
| | | | - Katja E. Hill
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff, United Kingdom
| | - Manon F. Pritchard
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff, United Kingdom
| | - David W. Thomas
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff, United Kingdom
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Powell LC, Cullen JK, Boyle GM, De Ridder T, Yap PY, Xue W, Pierce CJ, Pritchard MF, Menzies GE, Abdulkarim M, Adams JYM, Stokniene J, Francis LW, Gumbleton M, Johns J, Hill KE, Jones AV, Parsons PG, Reddell P, Thomas DW. Topical, immunomodulatory epoxy-tiglianes induce biofilm disruption and healing in acute and chronic skin wounds. Sci Transl Med 2022; 14:eabn3758. [DOI: 10.1126/scitranslmed.abn3758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The management of antibiotic-resistant, bacterial biofilm infections in chronic skin wounds is an increasing clinical challenge. Despite advances in diagnosis, many patients do not derive benefit from current anti-infective/antibiotic therapies. Here, we report a novel class of naturally occurring and semisynthetic epoxy-tiglianes, derived from the Queensland blushwood tree (
Fontainea picrosperma)
, and demonstrate their antimicrobial activity (modifying bacterial growth and inducing biofilm disruption), with structure/activity relationships established against important human pathogens. In vitro, the lead candidate EBC-1013 stimulated protein kinase C (PKC)–dependent neutrophil reactive oxygen species (ROS) induction and NETosis and increased expression of wound healing–associated cytokines, chemokines, and antimicrobial peptides in keratinocytes and fibroblasts. In vivo, topical EBC-1013 induced rapid resolution of infection with increased matrix remodeling in acute thermal injuries in calves. In chronically infected diabetic mouse wounds, treatment induced cytokine/chemokine production, inflammatory cell recruitment, and complete healing (in six of seven wounds) with ordered keratinocyte differentiation. These results highlight a nonantibiotic approach involving contrasting, orthogonal mechanisms of action combining targeted biofilm disruption and innate immune induction in the treatment of chronic wounds.
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Affiliation(s)
- Lydia C. Powell
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
- Centre for Nanohealth, Swansea University Medical School, Swansea University, Swansea SA2 8PP, UK
| | - Jason K. Cullen
- Drug Discovery Group, QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4006, Australia
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Glen M. Boyle
- Drug Discovery Group, QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4006, Australia
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Tom De Ridder
- QBiotics Group Limited Yungaburra, Queensland 4884, Australia
| | - Pei-Yi Yap
- Drug Discovery Group, QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4006, Australia
| | - Wenya Xue
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
| | - Carly J. Pierce
- Drug Discovery Group, QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4006, Australia
| | - Manon F. Pritchard
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
| | | | - Muthanna Abdulkarim
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK
| | - Jennifer Y. M. Adams
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
| | - Joana Stokniene
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
| | - Lewis W. Francis
- Centre for Nanohealth, Swansea University Medical School, Swansea University, Swansea SA2 8PP, UK
| | - Mark Gumbleton
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, UK
| | - Jenny Johns
- Drug Discovery Group, QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4006, Australia
| | - Katja E. Hill
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
| | - Adam V. Jones
- Oral Pathology, Cardiff and Vale University Health Board , Cardiff CF14 4XY, UK
| | - Peter G. Parsons
- Drug Discovery Group, QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4006, Australia
| | - Paul Reddell
- QBiotics Group Limited Yungaburra, Queensland 4884, Australia
| | - David W. Thomas
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
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5
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Francis LW, Yao SN, Powell LC, Griffiths S, Berquand A, Piasecki T, Howe W, Gazze AS, Farach-Carson MC, Constantinou P, Carson D, Margarit L, Gonzalez D, Conlan RS. Highly glycosylated MUC1 mediates high affinity L-selectin binding at the human endometrial surface. J Nanobiotechnology 2021; 19:50. [PMID: 33596915 PMCID: PMC7890821 DOI: 10.1186/s12951-021-00793-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 02/04/2021] [Indexed: 12/30/2022] Open
Abstract
Background Sialyl-Lewis X/L-selectin high affinity binding interactions between transmembrane O-glycosylated mucins proteins and the embryo have been implicated in implantation processes within the human reproductive system. However, the adhesive properties of these mucins at the endometrial cell surface are difficult to resolve due to known discrepancies between in vivo models and the human reproductive system and a lack of sensitivity in current in vitro models. To overcome these limitations, an in vitro model of the human endometrial epithelial was interrogated with single molecule force spectroscopy (SMFS) to delineate the molecular configurations of mucin proteins that mediate the high affinity L-selectin binding required for human embryo implantation. Results This study reveals that MUC1 contributes to both the intrinsic and extrinsic adhesive properties of the HEC-1 cellular surface. High expression of MUC1 on the cell surface led to a significantly increased intrinsic adhesion force (148 pN vs. 271 pN, p < 0.001), whereas this adhesion force was significantly reduced (271 pN vs. 118 pN, p < 0.001) following siRNA mediated MUC1 ablation. Whilst high expression of MUC1 displaying elevated glycosylation led to strong extrinsic (> 400 pN) L-selectin binding at the cell surface, low expression of MUC1 with reduced glycosylation resulted in significantly less (≤200 pN) binding events. Conclusions An optimal level of MUC1 together with highly glycosylated decoration of the protein is critical for high affinity L-selectin binding. This study demonstrates that MUC1 contributes to cellular adhesive properties which may function to facilitate trophoblast binding to the endometrial cell surface through the L-selectin/sialyl-Lewis x adhesion system subsequent to implantation.![]()
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Affiliation(s)
- Lewis W Francis
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Seydou N Yao
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Lydia C Powell
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Sean Griffiths
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | | | - Thomas Piasecki
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - William Howe
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Andrea S Gazze
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Mary C Farach-Carson
- School of Dentistry, The University of Texas Health Science Center, Houston, 77054, Texas, USA
| | - Pamela Constantinou
- Department of Biosciences, Wiess School of Natural Science, Rice University, Houston, Texas, 77251, USA
| | - Daniel Carson
- Department of Biosciences, Wiess School of Natural Science, Rice University, Houston, Texas, 77251, USA
| | - Lavinia Margarit
- Cwm Taf Morgannwg University Health Board, Princess of Wales Hospital, Bridgend, CF31 1RQ, UK
| | - Deya Gonzalez
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - R Steven Conlan
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, UK.
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Powell LC, Abdulkarim M, Stokniene J, Yang QE, Walsh TR, Hill KE, Gumbleton M, Thomas DW. Quantifying the effects of antibiotic treatment on the extracellular polymer network of antimicrobial resistant and sensitive biofilms using multiple particle tracking. NPJ Biofilms Microbiomes 2021; 7:13. [PMID: 33547326 PMCID: PMC7864955 DOI: 10.1038/s41522-020-00172-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 11/24/2020] [Indexed: 01/30/2023] Open
Abstract
Novel therapeutics designed to target the polymeric matrix of biofilms requires innovative techniques to accurately assess their efficacy. Here, multiple particle tracking (MPT) was developed to characterize the physical and mechanical properties of antimicrobial resistant (AMR) bacterial biofilms and to quantify the effects of antibiotic treatment. Studies employed nanoparticles (NPs) of varying charge and size (40-500 nm) in Pseudomonas aeruginosa PAO1 and methicillin-resistant Staphylococcus aureus (MRSA) biofilms and also in polymyxin B (PMB) treated Escherichia coli biofilms of PMB-sensitive (PMBSens) IR57 and PMB-resistant (PMBR) PN47 strains. NP size-dependent and strain-related differences in the diffusion coefficient values of biofilms were evident between PAO1 and MRSA. Dose-dependent treatment effects induced by PMB in PMBSens E. coli biofilms included increases in diffusion and creep compliance (P < 0.05), not evident in PMB treatment of PMBR E. coli biofilms. Our results highlight the ability of MPT to quantify the diffusion and mechanical effects of antibiotic therapies within the AMR biofilm matrix, offering a valuable tool for the pre-clinical screening of anti-biofilm therapies.
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Affiliation(s)
- Lydia C Powell
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff, UK.
- Centre of Nanohealth, Swansea University Medical School, Swansea University, Swansea, UK.
| | - Muthanna Abdulkarim
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK.
| | - Joana Stokniene
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff, UK
| | - Qiu E Yang
- Medical Microbiology and Infectious Disease, School of Medicine, Cardiff University, Cardiff, UK
| | - Timothy R Walsh
- Medical Microbiology and Infectious Disease, School of Medicine, Cardiff University, Cardiff, UK
| | - Katja E Hill
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff, UK
| | - Mark Gumbleton
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
| | - David W Thomas
- Advanced Therapies Group, Cardiff University School of Dentistry, Cardiff, UK
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7
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Jack AA, Nordli HR, Powell LC, Farnell DJJ, Pukstad B, Rye PD, Thomas DW, Chinga-Carrasco G, Hill KE. Cellulose Nanofibril Formulations Incorporating a Low-Molecular-Weight Alginate Oligosaccharide Modify Bacterial Biofilm Development. Biomacromolecules 2019; 20:2953-2961. [PMID: 31251598 DOI: 10.1021/acs.biomac.9b00522] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cellulose nanofibrils (CNFs) from wood pulp are a renewable material possessing advantages for biomedical applications because of their customizable porosity, mechanical strength, translucency, and environmental biodegradability. Here, we investigated the growth of multispecies wound biofilms on CNF formulated as aerogels and films incorporating the low-molecular-weight alginate oligosaccharide OligoG CF-5/20 to evaluate their structural and antimicrobial properties. Overnight microbial cultures were adjusted to 2.8 × 109 colony-forming units (cfu) mL-1 in Mueller Hinton broth and growth rates of Pseudomonas aeruginosa PAO1 and Staphylococcus aureus 1061A monitored for 24 h in CNF dispersions sterilized by γ-irradiation. Two CNF formulations were prepared (20 g m-2) with CNF as air-dried films or freeze-dried aerogels, with or without incorporation of an antimicrobial alginate oligosaccharide (OligoG CF-5/20) as a surface coating or bionanocomposite, respectively. The materials were structurally characterized by scanning electron microscopy (SEM) and laser profilometry (LP). The antimicrobial properties of the formulations were assessed using single- and mixed-species biofilms grown on the materials and analyzed using LIVE/DEAD staining with confocal laser scanning microscopy (CLSM) and COMSTAT software. OligoG-CNF suspensions significantly decreased the growth of both bacterial strains at OligoG concentrations >2.58% (P < 0.05). SEM showed that aerogel-OligoG bionanocomposite formulations had a more open three-dimensional structure, whereas LP showed that film formulations coated with OligoG were significantly smoother than untreated films or films incorporating PEG400 as a plasticizer (P < 0.05). CLSM of biofilms grown on films incorporating OligoG demonstrated altered biofilm architecture, with reduced biomass and decreased cell viability. The OligoG-CNF formulations as aerogels or films both inhibited pyocyanin production (P < 0.05). These novel CNF formulations or bionanocomposites were able to modify bacterial growth, biofilm development, and virulence factor production in vitro. These data support the potential of OligoG and CNF bionanocomposites for use in biomedical applications where prevention of infection or biofilm growth is required.
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Affiliation(s)
- Alison A Jack
- Advanced Therapies Group, Oral and Biomedical Sciences , Cardiff University School of Dentistry , Cardiff CF14 4XY , U.K
| | - Henriette R Nordli
- Department of Cancer Research and Molecular Medicine , NTNU , NO-7491 Trondheim , Norway
| | - Lydia C Powell
- Advanced Therapies Group, Oral and Biomedical Sciences , Cardiff University School of Dentistry , Cardiff CF14 4XY , U.K
| | - Damian J J Farnell
- Advanced Therapies Group, Oral and Biomedical Sciences , Cardiff University School of Dentistry , Cardiff CF14 4XY , U.K
| | - Brita Pukstad
- Department of Cancer Research and Molecular Medicine , NTNU , NO-7491 Trondheim , Norway.,Department of Dermatology, St. Olavs Hospital , Trondheim University Hospital , 7030 Trondheim , Norway
| | | | - David W Thomas
- Advanced Therapies Group, Oral and Biomedical Sciences , Cardiff University School of Dentistry , Cardiff CF14 4XY , U.K
| | | | - Katja E Hill
- Advanced Therapies Group, Oral and Biomedical Sciences , Cardiff University School of Dentistry , Cardiff CF14 4XY , U.K
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8
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Varache M, Powell LC, Aarstad OA, Williams TL, Wenzel MN, Thomas DW, Ferguson EL. Polymer Masked-Unmasked Protein Therapy: Identification of the Active Species after Amylase Activation of Dextrin-Colistin Conjugates. Mol Pharm 2019; 16:3199-3207. [PMID: 31125239 PMCID: PMC6779022 DOI: 10.1021/acs.molpharmaceut.9b00393] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Polymer
masked–unmasked protein therapy (PUMPT) uses conjugation
of a biodegradable polymer, such as dextrin, hyaluronic acid, or poly(l-glutamic acid), to mask a protein or peptide’s activity;
subsequent locally triggered degradation of the polymer at the target
site regenerates bioactivity in a controllable fashion. Although the
concept of PUMPT is well established, the relationship between protein
unmasking and reinstatement of bioactivity is unclear. Here, we used
dextrin–colistin conjugates to study the relationship between
the molecular structure (degree of unmasking) and biological activity.
Size exclusion chromatography was employed to collect fractions of
differentially degraded conjugates and ultraperformance liquid chromatography–mass
spectrometry (UPLC–MS) employed to characterize the corresponding
structures. Antimicrobial activity was studied using a minimum inhibitory
concentration (MIC) assay and confocal laser scanning microscopy of
LIVE/DEAD-stained biofilms with COMSTAT analysis. In vitro toxicity
of the degraded conjugate was assessed using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl
tetrazolium bromide assay. UPLC–MS revealed that the fully
“unmasked” dextrin–colistin conjugate composed
of colistin bound to at least one linker, whereas larger species were
composed of colistin with varying lengths of glucose units attached.
Increasing the degree of dextrin modification by succinoylation typically
led to a greater number of linkers bound to colistin. Greater antimicrobial
and antibiofilm activity were observed for the fully “unmasked”
conjugate compared to the partially degraded species (MIC = 0.25 and
2–8 μg/mL, respectively), whereas dextrin conjugation
reduced colistin’s in vitro toxicity toward kidney cells, even
after complete unmasking. This study highlights the importance of
defining the structure–antimicrobial activity relationship
for novel antibiotic derivatives and demonstrates the suitability
of LC–MS to aid the design of biodegradable polymer–antibiotic
conjugates.
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Affiliation(s)
- Mathieu Varache
- Advanced Therapies Group, Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences , Cardiff University , Heath Park , Cardiff CF14 4XY , U.K
| | - Lydia C Powell
- Advanced Therapies Group, Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences , Cardiff University , Heath Park , Cardiff CF14 4XY , U.K
| | - Olav A Aarstad
- Department of Biotechnology and Food Sciences , Norwegian University of Science and Technology , Trondheim 7491 , Norway
| | - Thomas L Williams
- School of Chemistry , Cardiff University , Main Building, Park Place , Cardiff CF10 3AT , U.K
| | - Margot N Wenzel
- School of Chemistry , Cardiff University , Main Building, Park Place , Cardiff CF10 3AT , U.K
| | - David W Thomas
- Advanced Therapies Group, Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences , Cardiff University , Heath Park , Cardiff CF14 4XY , U.K
| | - Elaine L Ferguson
- Advanced Therapies Group, Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences , Cardiff University , Heath Park , Cardiff CF14 4XY , U.K
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9
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Roberts AEL, Powell LC, Pritchard MF, Thomas DW, Jenkins RE. Anti-pseudomonad Activity of Manuka Honey and Antibiotics in a Specialized ex vivo Model Simulating Cystic Fibrosis Lung Infection. Front Microbiol 2019; 10:869. [PMID: 31105667 PMCID: PMC6491927 DOI: 10.3389/fmicb.2019.00869] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 04/04/2019] [Indexed: 01/22/2023] Open
Abstract
Pseudomonas aeruginosa causes problematic chronic lung infections in those suffering from cystic fibrosis. This is due to its antimicrobial resistance mechanisms and its ability to form robust biofilm communities with increased antimicrobial tolerances. Using novel antimicrobials or repurposing current ones is required in order to overcome these problems. Manuka honey is a natural antimicrobial agent that has been used for many decades in the treatment of chronic surface wounds with great success, particularly those infected with P. aeruginosa. Here we aim to determine whether the antimicrobial activity of manuka honey could potentially be repurposed to inhibit pulmonary P. aeruginosa infections using two ex vivo models. P. aeruginosa isolates (n = 28) from an international panel were tested for their susceptibility to manuka honey and clinically relevant antibiotics (ciprofloxacin, ceftazidime, and tobramycin), alone and in combination, using conventional antimicrobial susceptibility testing (AST). To increase clinical applicability, two ex vivo porcine lung (EVPL) models (using alveolar and bronchiolar tissue) were used to determine the anti-biofilm effects of manuka honey alone and in combination with antibiotics. All P. aeruginosa isolates were susceptible to manuka honey, however, varying incidences of resistance were seen against antibiotics. The combination of sub-inhibitory manuka honey and antibiotics using conventional AST had no effect on activity against the majority of isolates tested. Using the two ex vivo models, 64% (w/v) manuka honey inhibited many of the isolates where abnormally high concentrations of antibiotics could not. Typically, combinations of both manuka honey and antibiotics had increased antimicrobial activity. These results highlight the potential of manuka honey as a future antimicrobial for the treatment of pulmonary P. aeruginosa isolates, clearing potential infection reservoirs within the upper airway.
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Affiliation(s)
- Aled E L Roberts
- Department of Biomedical Sciences, Cardiff School of Health Sciences, Cardiff Metropolitan University, Cardiff, United Kingdom.,Swansea University Medical School, Swansea University, Swansea, United Kingdom
| | - Lydia C Powell
- School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom
| | - Manon F Pritchard
- School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom
| | - David W Thomas
- School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom
| | - Rowena E Jenkins
- Department of Biomedical Sciences, Cardiff School of Health Sciences, Cardiff Metropolitan University, Cardiff, United Kingdom.,Swansea University Medical School, Swansea University, Swansea, United Kingdom
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10
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Ferguson EL, Naseer S, Powell LC, Hardwicke J, Young FI, Zhu B, Liu Q, Song B, Thomas DW. Controlled release of dextrin-conjugated growth factors to support growth and differentiation of neural stem cells. Stem Cell Res 2018; 33:69-78. [PMID: 30321831 PMCID: PMC6288241 DOI: 10.1016/j.scr.2018.10.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 09/06/2018] [Accepted: 10/03/2018] [Indexed: 12/16/2022] Open
Abstract
An essential aspect of stem cell in vitro culture and in vivo therapy is achieving sustained levels of growth factors to support stem cell survival and expansion, while maintaining their multipotency and differentiation potential. This study investigated the ability of dextrin (~74,000 g/mol; 27.8 mol% succinoylation) conjugated to epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF; or FGF-2) (3.9 and 6.7% w/w protein loading, respectively) to support the expansion and differentiation of stem cells in vitro via sustained, controllable growth factor release. Supplementation of mouse neural stem cells (mNSCs) with dextrin-growth factor conjugates led to greater and prolonged proliferation compared to unbound EGF/bFGF controls, with no detectable apoptosis after 7 days of treatment. Immunocytochemical detection of neural precursor (nestin) and differentiation (Olig2, MAP2, GFAP) markers verified that controlled release of dextrin-conjugated growth factors preserves stem cell properties of mNSCs for up to 7 days. These results show the potential of dextrin-growth factor conjugates for localized delivery of bioactive therapeutic agents to support stem cell expansion and differentiation, and as an adjunct to direct neuronal repair.
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Affiliation(s)
- Elaine L Ferguson
- Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Heath Park, Cardiff CF14 4XY, UK; Cardiff Institute of Tissue Engineering and Repair, Cardiff University, 10 Museum Place, Cardiff, South Glamorgan, CF10 3BG, UK.
| | - Sameza Naseer
- Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Heath Park, Cardiff CF14 4XY, UK
| | - Lydia C Powell
- Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Heath Park, Cardiff CF14 4XY, UK; Cardiff Institute of Tissue Engineering and Repair, Cardiff University, 10 Museum Place, Cardiff, South Glamorgan, CF10 3BG, UK
| | - Joseph Hardwicke
- Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Heath Park, Cardiff CF14 4XY, UK; Cardiff Institute of Tissue Engineering and Repair, Cardiff University, 10 Museum Place, Cardiff, South Glamorgan, CF10 3BG, UK
| | - Fraser I Young
- Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Heath Park, Cardiff CF14 4XY, UK; Cardiff Institute of Tissue Engineering and Repair, Cardiff University, 10 Museum Place, Cardiff, South Glamorgan, CF10 3BG, UK
| | - Bangfu Zhu
- Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Heath Park, Cardiff CF14 4XY, UK
| | - Qian Liu
- Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Heath Park, Cardiff CF14 4XY, UK
| | - Bing Song
- Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Heath Park, Cardiff CF14 4XY, UK; Cardiff Institute of Tissue Engineering and Repair, Cardiff University, 10 Museum Place, Cardiff, South Glamorgan, CF10 3BG, UK
| | - David W Thomas
- Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Heath Park, Cardiff CF14 4XY, UK; Cardiff Institute of Tissue Engineering and Repair, Cardiff University, 10 Museum Place, Cardiff, South Glamorgan, CF10 3BG, UK
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11
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Powell LC, Pritchard MF, Ferguson EL, Powell KA, Patel SU, Rye PD, Sakellakou SM, Buurma NJ, Brilliant CD, Copping JM, Menzies GE, Lewis PD, Hill KE, Thomas DW. Targeted disruption of the extracellular polymeric network of Pseudomonas aeruginosa biofilms by alginate oligosaccharides. NPJ Biofilms Microbiomes 2018; 4:13. [PMID: 29977590 PMCID: PMC6026129 DOI: 10.1038/s41522-018-0056-3] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 05/20/2018] [Accepted: 06/06/2018] [Indexed: 11/29/2022] Open
Abstract
Acquisition of a mucoid phenotype by Pseudomonas sp. in the lungs of cystic fibrosis (CF) patients, with subsequent over-production of extracellular polymeric substance (EPS), plays an important role in mediating the persistence of multi-drug resistant (MDR) infections. The ability of a low molecular weight (Mn = 3200 g mol−1) alginate oligomer (OligoG CF-5/20) to modify biofilm structure of mucoid Pseudomonas aeruginosa (NH57388A) was studied in vitro using scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) with Texas Red (TxRd®)-labelled OligoG and EPS histochemical staining. Structural changes in treated biofilms were quantified using COMSTAT image-analysis software of CLSM z-stack images, and nanoparticle diffusion. Interactions between the oligomers, Ca2+ and DNA were studied using molecular dynamics (MD) simulations, Fourier transform infrared spectroscopy (FTIR) and isothermal titration calorimetry (ITC). Imaging demonstrated that OligoG treatment (≥0.5%) inhibited biofilm formation, revealing a significant reduction in both biomass and biofilm height (P < 0.05). TxRd®-labelled oligomers readily diffused into established (24 h) biofilms. OligoG treatment (≥2%) induced alterations in the EPS of established biofilms; significantly reducing the structural quantities of EPS polysaccharides, and extracellular (e)DNA (P < 0.05) with a corresponding increase in nanoparticle diffusion (P < 0.05) and antibiotic efficacy against established biofilms. ITC demonstrated an absence of rapid complex formation between DNA and OligoG and confirmed the interactions of OligoG with Ca2+ evident in FTIR and MD modelling. The ability of OligoG to diffuse into biofilms, potentiate antibiotic activity, disrupt DNA-Ca2+-DNA bridges and biofilm EPS matrix highlights its potential for the treatment of biofilm-related infections. Small carbohydrate molecules derived from marine algae show potential for inhibiting biofilm formation in multi-drug resistant infections. A research team led by Lydia Powell at Cardiff University, UK, investigated the action of carbohydrates called alginate oligosaccharides, composed of a small number of linked sugar molecules. The oligosaccharides modified and disrupted the structure of cultured biofilms of Pseudomonas aeruginosa, the cause of many serious drug resistant infections. This effect significantly inhibited the formation and maintenance of the biofilm state, which is known to be a crucial factor allowing the bacteria to resist drug treatment. Antibiotics proved more effective following the oligosaccharide intervention. The researchers uncovered key molecular details involved in the ability of the oligosaccharides to diffuse into and disrupt biofilms. The therapeutic potential of these small carbohydrates is currently being investigated in clinical trials.
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Affiliation(s)
- Lydia C Powell
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | - Manon F Pritchard
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | - Elaine L Ferguson
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | - Kate A Powell
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | - Shree U Patel
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | | | | | - Niklaas J Buurma
- 3Physical Organic Chemistry Centre, School of Chemistry, Cardiff University, Cardiff, UK
| | | | - Jack M Copping
- 4Respiratory Diagnostics Group, Swansea University, Swansea, UK
| | | | - Paul D Lewis
- 4Respiratory Diagnostics Group, Swansea University, Swansea, UK
| | - Katja E Hill
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
| | - David W Thomas
- 1Advanced Therapies Group, Cardiff University School of Dentistry, Heath Park, Cardiff, CF14 4XY UK
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12
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Jack AA, Nordli HR, Powell LC, Powell KA, Kishnani H, Johnsen PO, Pukstad B, Thomas DW, Chinga-Carrasco G, Hill KE. The interaction of wood nanocellulose dressings and the wound pathogen P. aeruginosa. Carbohydr Polym 2016; 157:1955-1962. [PMID: 27987916 DOI: 10.1016/j.carbpol.2016.11.080] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 11/25/2016] [Accepted: 11/28/2016] [Indexed: 12/22/2022]
Abstract
Chronic wounds pose an increasingly significant worldwide economic burden (over £1 billion per annum in the UK alone). With the escalation in global obesity and diabetes, chronic wounds will increasingly be a significant cause of morbidity and mortality. Cellulose nanofibrils (CNF) are highly versatile and can be tailored with specific physical properties to produce an assortment of three-dimensional structures (hydrogels, aerogels or films), for subsequent utilization as wound dressing materials. Growth curves using CNF (diameter <20nm) in suspension demonstrated an interesting dose-dependent inhibition of bacterial growth. In addition, analysis of biofilm formation (Pseudomonas aeruginosa PAO1) on nanocellulose aerogels (20g/m2) revealed significantly less biofilm biomass with decreasing aerogel porosity and surface roughness. Importantly, virulence factor production by P. aeruginosa in the presence of nanocellulose materials, quantified for the first time, was unaffected (p>0.05) over 24h. These data demonstrate the potential of nanocellulose materials in the development of novel dressings that may afford significant clinical potential.
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Affiliation(s)
- Alison A Jack
- Advanced Therapies Group, Oral and Biomedical Sciences, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK.
| | - Henriette R Nordli
- Department of Cancer Research and Molecular Medicine, NTNU, Trondheim, Norway
| | - Lydia C Powell
- Advanced Therapies Group, Oral and Biomedical Sciences, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
| | - Kate A Powell
- Advanced Therapies Group, Oral and Biomedical Sciences, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
| | - Himanshu Kishnani
- Advanced Therapies Group, Oral and Biomedical Sciences, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
| | | | - Brita Pukstad
- Department of Cancer Research and Molecular Medicine, NTNU, Trondheim, Norway; Department of Dermatology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
| | - David W Thomas
- Advanced Therapies Group, Oral and Biomedical Sciences, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
| | | | - Katja E Hill
- Advanced Therapies Group, Oral and Biomedical Sciences, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
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13
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Pritchard MF, Powell LC, Menzies GE, Lewis PD, Hawkins K, Wright C, Doull I, Walsh TR, Onsøyen E, Dessen A, Myrvold R, Rye PD, Myrset AH, Stevens HNE, Hodges LA, MacGregor G, Neilly JB, Hill KE, Thomas DW. A New Class of Safe Oligosaccharide Polymer Therapy To Modify the Mucus Barrier of Chronic Respiratory Disease. Mol Pharm 2016; 13:863-72. [PMID: 26833139 DOI: 10.1021/acs.molpharmaceut.5b00794] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The host- and bacteria-derived extracellular polysaccharide coating of the lung is a considerable challenge in chronic respiratory disease and is a powerful barrier to effective drug delivery. A low molecular weight 12-15-mer alginate oligosaccharide (OligoG CF-5/20), derived from plant biopolymers, was shown to modulate the polyanionic components of this coating. Molecular modeling and Fourier transform infrared spectroscopy demonstrated binding between OligoG CF-5/20 and respiratory mucins. Ex vivo studies showed binding induced alterations in mucin surface charge and porosity of the three-dimensional mucin networks in cystic fibrosis (CF) sputum. Human studies showed that OligoG CF-5/20 is safe for inhalation in CF patients with effective lung deposition and modifies the viscoelasticity of CF-sputum. OligoG CF-5/20 is the first inhaled polymer therapy, represents a novel mechanism of action and therapeutic approach for the treatment of chronic respiratory disease, and is currently in Phase IIb clinical trials for the treatment of CF.
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Affiliation(s)
- Manon F Pritchard
- Advanced Therapies Group, School of Dentistry, Cardiff University , Cardiff CF14 4XY, U.K
| | - Lydia C Powell
- Advanced Therapies Group, School of Dentistry, Cardiff University , Cardiff CF14 4XY, U.K
| | | | | | | | | | - Iolo Doull
- Respiratory/Cystic Fibrosis Unit, Children's Hospital for Wales , Cardiff CF14 4XW, U.K
| | - Timothy R Walsh
- Medical Microbiology, School of Medicine, College of Biomedical and Life Sciences, Cardiff University , Cardiff CF14 4EP, U.K
| | | | | | | | | | | | | | - Lee A Hodges
- Bio-Images Drug Delivery Ltd., Glasgow G4 0SF, U.K
| | | | | | - Katja E Hill
- Advanced Therapies Group, School of Dentistry, Cardiff University , Cardiff CF14 4XY, U.K
| | - David W Thomas
- Advanced Therapies Group, School of Dentistry, Cardiff University , Cardiff CF14 4XY, U.K
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14
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Rees A, Powell LC, Chinga-Carrasco G, Gethin DT, Syverud K, Hill KE, Thomas DW. 3D Bioprinting of Carboxymethylated-Periodate Oxidized Nanocellulose Constructs for Wound Dressing Applications. Biomed Res Int 2015; 2015:925757. [PMID: 26090461 PMCID: PMC4452270 DOI: 10.1155/2015/925757] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 09/30/2014] [Indexed: 11/23/2022]
Abstract
Nanocellulose has a variety of advantages, which make the material most suitable for use in biomedical devices such as wound dressings. The material is strong, allows for production of transparent films, provides a moist wound healing environment, and can form elastic gels with bioresponsive characteristics. In this study, we explore the application of nanocellulose as a bioink for modifying film surfaces by a bioprinting process. Two different nanocelluloses were used, prepared with TEMPO mediated oxidation and a combination of carboxymethylation and periodate oxidation. The combination of carboxymethylation and periodate oxidation produced a homogeneous material with short nanofibrils, having widths <20 nm and lengths <200 nm. The small dimensions of the nanofibrils reduced the viscosity of the nanocellulose, thus yielding a material with good rheological properties for use as a bioink. The nanocellulose bioink was thus used for printing 3D porous structures, which is exemplified in this study. We also demonstrated that both nanocelluloses did not support bacterial growth, which is an interesting property of these novel materials.
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Affiliation(s)
- Adam Rees
- Welsh Centre for Printing and Coating (WCPC), Swansea University, Swansea SA2 8PP, UK
| | - Lydia C. Powell
- Centre for NanoHealth, Swansea University, Swansea, UK
- Tissue Engineering and Reparative Dentistry, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
| | - Gary Chinga-Carrasco
- Paper and Fibre Research Institute (PFI), Høgskoleringen 6b, 7491 Trondheim, Norway
| | - David T. Gethin
- Welsh Centre for Printing and Coating (WCPC), Swansea University, Swansea SA2 8PP, UK
| | - Kristin Syverud
- Paper and Fibre Research Institute (PFI), Høgskoleringen 6b, 7491 Trondheim, Norway
| | - Katja E. Hill
- Tissue Engineering and Reparative Dentistry, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
| | - David W. Thomas
- Tissue Engineering and Reparative Dentistry, Cardiff University School of Dentistry, Cardiff CF14 4XY, UK
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15
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Affiliation(s)
- E B Dawson
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston
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16
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Tøndervik A, Sletta H, Klinkenberg G, Emanuel C, Powell LC, Pritchard MF, Khan S, Craine KM, Onsøyen E, Rye PD, Wright C, Thomas DW, Hill KE. Alginate oligosaccharides inhibit fungal cell growth and potentiate the activity of antifungals against Candida and Aspergillus spp. PLoS One 2014; 9:e112518. [PMID: 25409186 PMCID: PMC4237368 DOI: 10.1371/journal.pone.0112518] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 10/03/2014] [Indexed: 12/24/2022] Open
Abstract
The oligosaccharide OligoG, an alginate derived from seaweed, has been shown to have anti-bacterial and anti-biofilm properties and potentiates the activity of selected antibiotics against multi-drug resistant bacteria. The ability of OligoG to perturb fungal growth and potentiate conventional antifungal agents was evaluated using a range of pathogenic fungal strains. Candida (n = 11) and Aspergillus (n = 3) spp. were tested using germ tube assays, LIVE/DEAD staining, scanning electron microscopy (SEM), atomic force microscopy (AFM) and high-throughput minimum inhibition concentration assays (MICs). In general, the strains tested showed a significant dose-dependent reduction in cell growth at ≥6% OligoG as measured by optical density (OD600; P<0.05). OligoG (>0.5%) also showed a significant inhibitory effect on hyphal growth in germ tube assays, although strain-dependent variations in efficacy were observed (P<0.05). SEM and AFM both showed that OligoG (≥2%) markedly disrupted fungal biofilm formation, both alone, and in combination with fluconazole. Cell surface roughness was also significantly increased by the combination treatment (P<0.001). High-throughput robotic MIC screening demonstrated the potentiating effects of OligoG (2, 6, 10%) with nystatin, amphotericin B, fluconazole, miconazole, voriconazole or terbinafine with the test strains. Potentiating effects were observed for the Aspergillus strains with all six antifungal agents, with an up to 16-fold (nystatin) reduction in MIC. Similarly, all the Candida spp. showed potentiation with nystatin (up to 16-fold) and fluconazole (up to 8-fold). These findings demonstrate the antifungal properties of OligoG and suggest a potential role in the management of fungal infections and possible reduction of antifungal toxicity.
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Affiliation(s)
- Anne Tøndervik
- Department of Bioprocess Technology, SINTEF Materials and Chemistry, N-7465 Trondheim, Norway
| | - Håvard Sletta
- Department of Bioprocess Technology, SINTEF Materials and Chemistry, N-7465 Trondheim, Norway
- * E-mail:
| | - Geir Klinkenberg
- Department of Bioprocess Technology, SINTEF Materials and Chemistry, N-7465 Trondheim, Norway
| | - Charlotte Emanuel
- Advanced Therapies Group, Tissue Engineering and Reparative Dentistry, Cardiff University School of Dentistry, Cardiff, CF14 4XY, United Kingdom
| | - Lydia C. Powell
- Advanced Therapies Group, Tissue Engineering and Reparative Dentistry, Cardiff University School of Dentistry, Cardiff, CF14 4XY, United Kingdom
| | - Manon F. Pritchard
- Advanced Therapies Group, Tissue Engineering and Reparative Dentistry, Cardiff University School of Dentistry, Cardiff, CF14 4XY, United Kingdom
| | - Saira Khan
- Advanced Therapies Group, Tissue Engineering and Reparative Dentistry, Cardiff University School of Dentistry, Cardiff, CF14 4XY, United Kingdom
| | - Kieron M. Craine
- Advanced Therapies Group, Tissue Engineering and Reparative Dentistry, Cardiff University School of Dentistry, Cardiff, CF14 4XY, United Kingdom
| | - Edvar Onsøyen
- AlgiPharma AS, Industriveien 33, N-1337 Sandvika, Norway
| | - Phil D. Rye
- AlgiPharma AS, Industriveien 33, N-1337 Sandvika, Norway
| | - Chris Wright
- Centre for NanoHealth, Systems and Process Engineering Centre, College of Engineering, Swansea University, Swansea, SA2 8PP, United Kingdom
| | - David W. Thomas
- Advanced Therapies Group, Tissue Engineering and Reparative Dentistry, Cardiff University School of Dentistry, Cardiff, CF14 4XY, United Kingdom
| | - Katja E. Hill
- Advanced Therapies Group, Tissue Engineering and Reparative Dentistry, Cardiff University School of Dentistry, Cardiff, CF14 4XY, United Kingdom
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17
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Powell LC, Pritchard MF, Emanuel C, Onsøyen E, Rye PD, Wright CJ, Hill KE, Thomas DW. A Nanoscale Characterization of the Interaction of a Novel Alginate Oligomer with the Cell Surface and Motility ofPseudomonas aeruginosa. Am J Respir Cell Mol Biol 2014; 50:483-92. [DOI: 10.1165/rcmb.2013-0287oc] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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18
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Roberts JL, Khan S, Emanuel C, Powell LC, Pritchard MF, Onsøyen E, Myrvold R, Thomas DW, Hill KE. An in vitro study of alginate oligomer therapies on oral biofilms. J Dent 2013; 41:892-9. [PMID: 23907083 DOI: 10.1016/j.jdent.2013.07.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/12/2013] [Accepted: 07/18/2013] [Indexed: 10/26/2022] Open
Abstract
OBJECTIVES The in vitro effect of a novel, oligosaccharide nanomedicine OligoG against oral pathogen-related biofilms, both alone and in the presence of the conventional anti-bacterial agent triclosan, was evaluated. METHODS The effect of OligoG±triclosan was assessed against established Streptococcus mutans and Porphyromonas gingivalis biofilms by bacterial counts and image analysis using LIVE/DEAD(®) staining and atomic force microscopy (AFM). The effect of triclosan and OligoG surface pre-treatments on bacterial attachment to titanium and polymethylmethacrylate was also studied. RESULTS OligoG potentiated the antimicrobial effect of triclosan, particularly when used in combination at 0.3% against S. mutans grown in artificial saliva. OligoG was less effective against established P. gingivalis biofilms. However, attachment of P. gingivalis, to titanium in particular, was significantly reduced after surface pre-treatment with OligoG and triclosan at 0.01% when compared to controls. Light microscopy and AFM showed that OligoG was biocidal to P. gingivalis, but not S. mutans. CONCLUSIONS OligoG and triclosan when used in combination produced an enhanced antimicrobial effect against two important oral pathogens and reduced bacterial attachment to dental materials such as titanium, even at reduced triclosan concentrations. Whilst the use of triclosan against oral bacteria has been widely documented, its synergistic use with OligoG described here, has not previously been reported. The use of lower concentrations of triclosan, if used in combination therapy with OligoG, could have environmental benefits. CLINICAL IMPORTANCE The potentiation of antimicrobial agents by naturally occurring oligomers such as OligoG may represent a novel, safe adjunct to conventional oral hygiene and periodontal therapy. The ability of OligoG to inhibit the growth and impair bacterial adherence highlights its potential in the management of peri-implantitis.
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Affiliation(s)
- J L Roberts
- Wound Biology Group, Tissue Engineering and Reparative Dentistry, Cardiff University School of Dentistry, Heath Park, Cardiff CF14 4XY, UK
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Powell LC, Sowedan A, Khan S, Wright CJ, Hawkins K, Onsøyen E, Myrvold R, Hill KE, Thomas DW. The effect of alginate oligosaccharides on the mechanical properties of Gram-negative biofilms. Biofouling 2013; 29:413-21. [PMID: 23574333 DOI: 10.1080/08927014.2013.777954] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The influence of a novel, safe antibiofilm therapy on the mechanical properties of Pseudomonas aeruginosa and Acinetobacter baumannii biofilms in vitro was characterized. A multiscale approach employing atomic force microscopy (AFM) and rheometry was used to quantify the mechanical disruption of the biofilms by a therapeutic polymer based on a low-molecular weight alginate oligosaccharide (OligoG). AFM demonstrated structural alterations in the biofilms exposed to OligoG, with significantly lower Young's moduli than the untreated biofilms, (149 MPa vs 242 MPa; p < 0.05), a decreased resistance to hydrodynamic shear and an increased surface irregularity (Ra) in the untreated controls (35.2 nm ± 7.6 vs 12.1 nm ± 5.4; p < 0.05). Rheology demonstrated that increasing clinically relevant concentrations of OligoG (<10%) were associated with an increasing phase angle (δ) over a wide range of frequencies (0.1-10 Hz). These results highlight the utility of these techniques for the study of three-dimensional biofilms and for quantifying novel disruption therapies in vitro.
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Affiliation(s)
- Lydia C Powell
- Tissue Engineering and Reparative Dentistry, Wound Biology Group, School of Dentistry, Cardiff University, Cardiff, UK
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Abstract
Atomic Force Microscopy (AFM) has proven itself over recent years as an essential tool for the analysis of microbial systems. This article will review how AFM has been used to study microbial systems to provide unique insight into their behavior and relationship with their environment. Immobilization of live cells has enabled AFM imaging and force measurement to provide understanding of the structure and function of numerous microbial cells. At the macromolecular level AFM investigation into the properties of surface macromolecules and the energies associated with their mechanical conformation and functionality has helped unravel the complex interactions of microbial cells. At the level of the whole cell AFM has provided an integrated analysis of how the microbial cell exploits its environment through its selective, adaptable interface, the cell surface. In addition to these areas of study the AFM investigation of microbial biofilms has been vital for industrial and medical process analysis. There exists a tremendous potential for the future application of AFM to microbial systems and this has been strengthened by the trend to use AFM in combination with other characterization methods, such as confocal microscopy and Raman spectroscopy, to elucidate dynamic cellular processes.
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Affiliation(s)
- Chris J Wright
- Multidisciplinary Nanotechnology Centre, School of Engineering, Swansea University, Swansea, United Kingdom.
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Abstract
Increased consumption of tomatoes and tomato products has been associated with decreased cancer risks. One fat-soluble compound identified in tomatoes which may be responsible for this association is lycopene. There may, however, be other antioxidants present in tomato-based foods, and total antioxidant capacity may be another way to rate the health benefits of these foods. In this work, we examined the Trolox-equivalent antioxidant capacity (TEAC) of aqueous and organic extracts of lycopene-containing foods: ketchup, fresh tomatoes, tomato paste, tomato sauce, tomato soup, tomato juice, vegetable juice, canned tomatoes and watermelon. Antioxidant activity in these food extracts was greater in the aqueous versus organic fractions, except for watermelon and tomato sauce where the levels were similar in the two fractions. Lycopene levels in the food samples tested, however, were relatively greater in the organic fractions, with the exception of the two juices, which had similar levels in the two fractions, and two highly concentrated tomato products, tomato paste and ketchup, which had relatively higher lycopene levels in the aqueous fractions. The foods with the highest antioxidant capacity per serving overall (tomato soup was highest) did not have the highest lycopene levels. This indicates that it may be important to consume a variety of tomato-containing products in order to obtain the largest variety of dietary antioxidants possible.
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Affiliation(s)
- Z Djuric
- Barbara Ann Karmanos Cancer Institute, 110 East Warren, Detroit, MI 48201, USA
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Abstract
This study compares the seminal plasma trace metal levels of hospital workers with groups of industrial workers in a petroleum refinery, smelter, and chemical plant. The metals measured were the essential metals (copper, zinc, nickel, cobalt, and manganese) and the toxic metals (lead, cadmium, and aluminum). The group mean +/- SE metal level for each group (50 subjects per group) was calculated, and the statistical significance of the group mean differences of the industrial groups with the hospital group (control) was determined by the Student's t-test. The differences observed in the smelter group were increased copper and zinc (p < or = 0.001) and decreased nickel, cobalt, and manganese (p < or = 0.001, < or = 0.01). The refinery group differences were increased copper, zinc, and nickel (p < or = 0.001) but decreased cobalt and manganese (p < or = 0.001). The chemical group differences were increased zinc (p < or = 0.001) and decreased cobalt (p < or = 0.001). The seminal plasma levels of the toxic metals lead and aluminum were increased in each of the industrial groups (p < or = 0.001). Concurrent differences were (1) decreased accumulation of nickel, cobalt, and manganese in the smelter group, (2) decreased cobalt and manganese in the refinery group, and (3) only decreased cobalt in the chemical group.
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Affiliation(s)
- E B Dawson
- Department of Obstetrics & Gynecology, The University of Texas Medical Branch, Galveston 77555, USA
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Abstract
This study compares the semen levels of lead (Pb), cadmium (Cd), and aluminum (Al) in relation to live sperm in semen samples from 64 apparently healthy men. The measured levels were separated into live sperm count tertiles (<25% [18 subjects], 25-50% [26 subjects], and >50% [20 subjects]). The mean +/- SD for each group was calculated, and the difference between the means of the high and low tertiles were compared by ANOVA. Significant differences were observed between the high and low live sperm groups for Pb (p < 0.01) and Al (p < 0.05), but not Cd. Spearman's rank correlation between sperm viability and the semen plasma metal levels showed a direct relation to Mg (p < 0.05). However, there was an inverse relation to lead (p < 0.001), cadmium (p < 0.01), and aluminum (p < 0.01). There was no significant correlation between Ca and Zn. Linear regression between the live sperm counts and semen level of the three metals show that metal levels were inversely correlated with the percentage of live sperm (p < 0.001, < 0.01). Apparently, the presence of these metals in the environment and in seminal plasma exerts a toxic effect on sperm.
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Affiliation(s)
- E B Dawson
- Department of Obstetrics and Gynecology, The University of Texas Medical Branch at Galveston, USA
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Dawson EB, Harris WA, Teter MC, Powell LC. Effect of ascorbic acid supplementation on the sperm quality of smokers. Fertil Steril 1992; 58:1034-9. [PMID: 1426355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE To determine the effect of ascorbic acid supplementation on the sperm quality of heavy smokers. DESIGN Microscopic examination of semen for 1 month during supplementation with placebo or ascorbic acid at dose levels of 200 or 1,000 mg/d. SETTING Department of Obstetrics and Gynecology, The University of Texas Medical Branch. PARTICIPANTS Seventy-five men (20 to 35 years old) randomly divided into one of three supplementation groups: placebo, 200 mg and 1,000 mg of ascorbic acid. MAIN OUTCOME Improvement in sperm quality as compared with presupplementation levels and between the three treatment groups. RESULTS The placebo group showed no improvement in sperm quality. The groups receiving ascorbic acid showed improvement in sperm quality with most improvement in the 1,000-mg group. Pearson's correlation showed statistically significant relationships between the weekly group means of serum and seminal plasma ascorbic acid levels and sperm qualities. CONCLUSIONS Ascorbic acid supplementation of heavy smokers in excess of 200 mg/d results in improved sperm quality.
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Affiliation(s)
- E B Dawson
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston 77555
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Dinh TV, Powell LC, Hannigan EV, Yang HL, Wirt DP, Yandell RB. Simultaneously occurring condylomata acuminata, carcinoma in situ and verrucous carcinoma of the vulva and carcinoma in situ of the cervix in a young woman. A case report. J Reprod Med 1988; 33:510-3. [PMID: 3404512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A case of simultaneously occurring condylomata acuminata, carcinoma in situ and verrucous carcinoma of the vulva and carcinoma in situ of the cervix was seen in a 26-year-old woman. In situ DNA hybridization on sections of the condyloma acuminata and verrucous carcinoma yielded DNA sequences for human papillomavirus 6.
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Affiliation(s)
- T V Dinh
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston 77550
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Powell LC, Dinh TV, Rajaraman S, Hannigan EV, Dillard EA, Yandell RB, To T. Carcinoma in situ of the vulva. A clinicopathologic study of 50 cases. J Reprod Med 1986; 31:808-14. [PMID: 3772899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The authors reviewed 50 cases of carcinoma in situ of the vulva treated at the University of Texas Medical Branch, Galveston, from 1975 to 1984. Sixty-two percent of the patients were premenopausal. The most frequent complaint was vulvar itching. Twenty-six percent of the patients were asymptomatic. Recurrences were frequent (25%) and were associated with multifocal lesions, involved surgical margins and the bowenoid histologic type. Superficially invasive carcinoma was detected in 8% of patients, mostly postmenopausal women with simplex histologic types. Immunohistochemical studies failed to detect papillomavirus- or herpesvirus-associated antigens in any of the cases. Follow-up of 48 patients from six months to ten years revealed no mortality from invasive cancer.
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Slavin RE, Christie JD, Swedo J, Powell LC. Locally aggressive granular cell tumor causing priapism of the crus of the clitoris. A light and ultrastructural study, with observations concerning the pathogenesis of fibrosis of the corpus cavernosum in priapism. Am J Surg Pathol 1986; 10:497-507. [PMID: 3014914 DOI: 10.1097/00000478-198607000-00007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A case of focal priapism of the clitoris caused by a microscopic granular cell tumor (GCT) is described. This neoplasm is considered locally aggressive because it invades the lumens of peripheral cavernous sinuses of the crus of the clitoris. Caverns adjacent to those invaded by tumor exhibit stasis, telangiectasia, and necrosis of the smooth muscle of the trabecular wall. These alterations lead to telescoping collapse and compression of the cavernous spaces and culminate in fibrosis. Ultrastructurally, replicated basal lamina is found surrounding clusters of granular cells. We suspect that the multilayered lamina, in addition to being produced by tumor cells, is derived from the trabecular endothelium surrounding the caverns invaded by the GCT. The replication of the basal lamina may be provoked by cycles of injury and repair to these vessels caused by repeated episodes of prolonged vascular stasis. A peculiar large vein with perforating branches was observed in the center of the cavernous spaces of the crus. This vein is not found in normal crura and, therefore, represents a morphologic adaptation created to drain the cavernous spaces.
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Abstract
To test the hypothesis that neutrophils and macrophages in human milk may not defend by classical inflammatory mechanisms, experiments were conducted to ascertain whether adherence, orientation, and directed motility of these leukocytes would be enhanced by exposure to chemoattractant peptides including N-formyl-L-methionyl-L-phenylalanine and N-formyl-L-methionyl-L-leucyl-L-phenylalanine and C5a generated from zymosan activated human serum. Adherence and spatial orientation were tested on coverglasses and in Zigmond chambers, and chemotaxis was examined by Boyden chambers and a subagarose technique. Whereas, the adherence, orientation, and directed movement of adult peripheral blood neutrophils and monocytes were significantly enhanced by those chemotactic agents, human milk leukocytes failed to respond. The failure of the response of human milk leukocytes was not due to alterations in maternal peripheral blood leukocytes but appeared to be due partially to inhibitors in human milk. The experiments suggest that human milk leukocytes may be modified in the mammary gland to protect by noninflammatory mechanisms.
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Abstract
A modification of the classic Marshall-Marchetti-Krantz (MMK) operation which includes suspending the urethrovesical junction to the pubis by the vaginal approach is presented. This offers the advantages of a shorter operating time, the lack of an abdominal incision, and the concomitant repair of other pelvic anatomic defects through the vagina, with a cure rate at least equal to, if not better than, that associated with the abdominal route. The study group of 25 patients had less morbidity, a 1-day decrease in hospital stay, and 1 1/2 fewer days of catheter drainage compared to a matched control group of MMK operations done abdominally in this preliminary report. A 96% cure and improvement rate of the symptoms of stress incontinence was shown at the 6-week postoperative visit. This compares to a 92% rate in the control series of abdominal MMKs. The permanency of the procedure will have to be evaluated critically as more cases are added and sufficient time elapses to see if these good initial results hold up.
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Vaughn TC, Powell LC. The obstetrical management of conjoined twins. Obstet Gynecol 1979; 53:67S-72S. [PMID: 424132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A pair of conjoined twins (thoracopagus) was delivered abdominally after antepartum diagnosis. Obstetrical planning is more likely to be successful with antepartum diagnosis, which can be done only if the possibility of conjoining is considered with each twin gestation. Once a twin gestation is suspected, ultrasonography should be performed for confirmation. Conjoined twins should be suspected in a gravid mother with multiple gestations and an abnormal fetal attitude. When the images cannot be separated on ultrasonography, amniographic examination, using a double contrast medium of oil-water, should demonstrate dye in the gastrointestinal tract and a union between the twins, as well as establish the presence of a monoamniotic sac. Because of increased fetal morbidity and mortality of vaginal delivery in monoamniotic twins, even if not conjoined, elective cesarean section at term will ensure the best chance for fetal survival.
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Powell LC. Condyloma acuminatum: recent advances in development, carcinogenesis, and treatment. Clin Obstet Gynecol 1978; 21:1061-79. [PMID: 737920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
Medroxyprogesterone acetate is a steroid compound similar to progesterone in structure and function. Thirty women were given 150 mg. of medroxyprogesterone intramuscularly, and samples of the endometrium were examined by light and electron microscopy. The initial response of normal human endometrium was maturation and then inhibition. By 50 days after injection, the atrophic changes began to reverse, and by Day 90, after injection the tissue resembled normal proliferative endometrium. A previously undescribed nuclear inclusion body is present; however, its significance is unclear at this time. On the basis of ultrastructural changes, medroxyprogesterone appeared not to exert a significant influence on the endometrium past 90 days at this dosage.
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Powell LC, Schreiber MH. Intrauterine fetal transfusion. Radiol Clin North Am 1974; 12:37-58. [PMID: 4820826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Rappoport DA, Powell LC, Myers JL. Prenatal determination of fetal lung maturation by amniocentesis. Tex Med 1972; 68:98-9. [PMID: 5066963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Seymour RJ, Powell LC. Depo-medroxyprogesterone acetate as a contraceptive. Obstet Gynecol 1970; 36:589-96. [PMID: 5506464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Smith SA, Powell LC, Essin EM. Ehlers-Danlos syndrome and pregnancy. Report of a case. Obstet Gynecol 1968; 32:331-5. [PMID: 5742115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Powell LC. Eradicate Rh hemolytic disease by preventing Rh sensitization. Tex Med 1968; 64:27-8. [PMID: 4969885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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