Bactericidal and anti-biofilm effects of uncharged and cationic ultrasound-responsive nitric oxide microbubbles on Pseudomonas aeruginosa biofilms
Bacterial biofilms are a major and ongoing concern for public health, featuring both inherited genetic resistance traits and a conferred innate tolerance to traditional antibiotic therapies. Consequently, there is a growing need for novel methods of drug delivery, to increase the efficacy of antimic...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-08-01
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| Series: | Frontiers in Cellular and Infection Microbiology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fcimb.2022.956808/full |
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| author | Gareth LuTheryn Gareth LuTheryn Charlotte Hind Christopher Campbell Aaron Crowther Qiang Wu Sara B. Keller Peter Glynne-Jones J. Mark Sutton Jeremy S. Webb Michael Gray Sandra A. Wilks Eleanor Stride Dario Carugo |
| author_facet | Gareth LuTheryn Gareth LuTheryn Charlotte Hind Christopher Campbell Aaron Crowther Qiang Wu Sara B. Keller Peter Glynne-Jones J. Mark Sutton Jeremy S. Webb Michael Gray Sandra A. Wilks Eleanor Stride Dario Carugo |
| author_sort | Gareth LuTheryn |
| collection | DOAJ |
| description | Bacterial biofilms are a major and ongoing concern for public health, featuring both inherited genetic resistance traits and a conferred innate tolerance to traditional antibiotic therapies. Consequently, there is a growing need for novel methods of drug delivery, to increase the efficacy of antimicrobial agents. This research evaluated the anti-biofilm and bactericidal effects of ultrasound responsive gas-microbubbles (MBs) of either air or nitric oxide, using an in vitro Pseudomonas aeruginosa biofilm model grown in artificial wound medium. The four lipid-based MB formulations evaluated were room-air MBs (RAMBs) and nitric oxide MBs (NOMBs) with no electrical charge, as well as cationic (+) RAMBs+ and NOMBs+. Two principal treatment conditions were used: i) ultrasound stimulated MBs only, and ii) ultrasound stimulated MBs with a sub-inhibitory concentration (4 µg/mL) of the antibiotic gentamicin. The total treatment time was divided into a 60 second passive MB interaction period prior to 40 second ultrasound exposure; each MB formulation was tested in triplicate. Ultrasound stimulated RAMBs and NOMBs without antibiotic achieved reductions in biofilm biomass of 93.3% and 94.0%, respectively. Their bactericidal efficacy however was limited, with a reduction in culturable cells of 26.9% and 65.3%, respectively. NOMBs with sub-inhibitory antibiotic produced the most significant reduction in biofilm biomass, corresponding to a 99.9% (SD ± 5.21%); and a 99.9% (SD ± 0.07%) (3-log) reduction in culturable bacterial cells. Cationic MBs were initially manufactured to promote binding of MBs to negatively charged biofilms, but these formulations also demonstrated intrinsic bactericidal properties. In the absence of antibiotic, the bactericidal efficacy of RAMB+ and NOMB+ was greater that of uncharged counterparts, reducing culturable cells by 84.7% and 86.1% respectively; increasing to 99.8% when combined with antibiotic. This study thus demonstrates the anti-biofilm and bactericidal utility of ultrasound stimulated MBs, and specifically is the first to demonstrate the efficacy of a NOMB for the dispersal and potentiation of antibiotics against bacterial biofilms in vitro. Importantly the biofilm system and complex growth-medium were selected to recapitulate key morphological features of in vivo biofilms. The results us offer new insight for the development of new clinical treatments, for example, in chronic wounds. |
| first_indexed | 2024-04-12T08:01:18Z |
| format | Article |
| id | doaj.art-a7b55206fe9d4e8fb929bc32c4936caa |
| institution | Directory Open Access Journal |
| issn | 2235-2988 |
| language | English |
| last_indexed | 2024-04-12T08:01:18Z |
| publishDate | 2022-08-01 |
| publisher | Frontiers Media S.A. |
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| series | Frontiers in Cellular and Infection Microbiology |
| spelling | doaj.art-a7b55206fe9d4e8fb929bc32c4936caa2022-12-22T03:41:19ZengFrontiers Media S.A.Frontiers in Cellular and Infection Microbiology2235-29882022-08-011210.3389/fcimb.2022.956808956808Bactericidal and anti-biofilm effects of uncharged and cationic ultrasound-responsive nitric oxide microbubbles on Pseudomonas aeruginosa biofilmsGareth LuTheryn0Gareth LuTheryn1Charlotte Hind2Christopher Campbell3Aaron Crowther4Qiang Wu5Sara B. Keller6Peter Glynne-Jones7J. Mark Sutton8Jeremy S. Webb9Michael Gray10Sandra A. Wilks11Eleanor Stride12Dario Carugo13University College London (UCL) School of Pharmacy, Department of Pharmaceutics, University College London, London, United KingdomFaculty of Engineering and Physical Sciences, University of Southampton, Southampton, United KingdomHealthcare Biotechnology, United Kingdom Health Security Agency (UKHSA), Porton Down, Salisbury, United KingdomFaculty of Engineering and Physical Sciences, University of Southampton, Southampton, United KingdomUniversity College London (UCL) School of Pharmacy, Department of Pharmaceutics, University College London, London, United KingdomInstitute of Biomedical Engineering, University of Oxford, Oxford, United KingdomInstitute of Biomedical Engineering, University of Oxford, Oxford, United KingdomFaculty of Engineering and Physical Sciences, University of Southampton, Southampton, United KingdomHealthcare Biotechnology, United Kingdom Health Security Agency (UKHSA), Porton Down, Salisbury, United KingdomSchool of Biological Sciences, Faculty of Environmental and Life Sciences, National Biofilms Innovation Centre (NBIC) and Institute for Life Sciences, University of Southampton, Southampton, United KingdomInstitute of Biomedical Engineering, University of Oxford, Oxford, United KingdomSchool of Health Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United KingdomInstitute of Biomedical Engineering, University of Oxford, Oxford, United KingdomUniversity College London (UCL) School of Pharmacy, Department of Pharmaceutics, University College London, London, United KingdomBacterial biofilms are a major and ongoing concern for public health, featuring both inherited genetic resistance traits and a conferred innate tolerance to traditional antibiotic therapies. Consequently, there is a growing need for novel methods of drug delivery, to increase the efficacy of antimicrobial agents. This research evaluated the anti-biofilm and bactericidal effects of ultrasound responsive gas-microbubbles (MBs) of either air or nitric oxide, using an in vitro Pseudomonas aeruginosa biofilm model grown in artificial wound medium. The four lipid-based MB formulations evaluated were room-air MBs (RAMBs) and nitric oxide MBs (NOMBs) with no electrical charge, as well as cationic (+) RAMBs+ and NOMBs+. Two principal treatment conditions were used: i) ultrasound stimulated MBs only, and ii) ultrasound stimulated MBs with a sub-inhibitory concentration (4 µg/mL) of the antibiotic gentamicin. The total treatment time was divided into a 60 second passive MB interaction period prior to 40 second ultrasound exposure; each MB formulation was tested in triplicate. Ultrasound stimulated RAMBs and NOMBs without antibiotic achieved reductions in biofilm biomass of 93.3% and 94.0%, respectively. Their bactericidal efficacy however was limited, with a reduction in culturable cells of 26.9% and 65.3%, respectively. NOMBs with sub-inhibitory antibiotic produced the most significant reduction in biofilm biomass, corresponding to a 99.9% (SD ± 5.21%); and a 99.9% (SD ± 0.07%) (3-log) reduction in culturable bacterial cells. Cationic MBs were initially manufactured to promote binding of MBs to negatively charged biofilms, but these formulations also demonstrated intrinsic bactericidal properties. In the absence of antibiotic, the bactericidal efficacy of RAMB+ and NOMB+ was greater that of uncharged counterparts, reducing culturable cells by 84.7% and 86.1% respectively; increasing to 99.8% when combined with antibiotic. This study thus demonstrates the anti-biofilm and bactericidal utility of ultrasound stimulated MBs, and specifically is the first to demonstrate the efficacy of a NOMB for the dispersal and potentiation of antibiotics against bacterial biofilms in vitro. Importantly the biofilm system and complex growth-medium were selected to recapitulate key morphological features of in vivo biofilms. The results us offer new insight for the development of new clinical treatments, for example, in chronic wounds.https://www.frontiersin.org/articles/10.3389/fcimb.2022.956808/fullbiofilmsnitric oxide (NO)microbubble (MB)sonobactericidechronic woundsultrasound |
| spellingShingle | Gareth LuTheryn Gareth LuTheryn Charlotte Hind Christopher Campbell Aaron Crowther Qiang Wu Sara B. Keller Peter Glynne-Jones J. Mark Sutton Jeremy S. Webb Michael Gray Sandra A. Wilks Eleanor Stride Dario Carugo Bactericidal and anti-biofilm effects of uncharged and cationic ultrasound-responsive nitric oxide microbubbles on Pseudomonas aeruginosa biofilms Frontiers in Cellular and Infection Microbiology biofilms nitric oxide (NO) microbubble (MB) sonobactericide chronic wounds ultrasound |
| title | Bactericidal and anti-biofilm effects of uncharged and cationic ultrasound-responsive nitric oxide microbubbles on Pseudomonas aeruginosa biofilms |
| title_full | Bactericidal and anti-biofilm effects of uncharged and cationic ultrasound-responsive nitric oxide microbubbles on Pseudomonas aeruginosa biofilms |
| title_fullStr | Bactericidal and anti-biofilm effects of uncharged and cationic ultrasound-responsive nitric oxide microbubbles on Pseudomonas aeruginosa biofilms |
| title_full_unstemmed | Bactericidal and anti-biofilm effects of uncharged and cationic ultrasound-responsive nitric oxide microbubbles on Pseudomonas aeruginosa biofilms |
| title_short | Bactericidal and anti-biofilm effects of uncharged and cationic ultrasound-responsive nitric oxide microbubbles on Pseudomonas aeruginosa biofilms |
| title_sort | bactericidal and anti biofilm effects of uncharged and cationic ultrasound responsive nitric oxide microbubbles on pseudomonas aeruginosa biofilms |
| topic | biofilms nitric oxide (NO) microbubble (MB) sonobactericide chronic wounds ultrasound |
| url | https://www.frontiersin.org/articles/10.3389/fcimb.2022.956808/full |
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