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Cullen A, Rajagopal A, Heintz K, Heise A, Murphy R, Sazanovich IV, Greetham GM, Towrie M, Long C, Fitzgerald-Hughes D, Pryce MT. Exploiting a Neutral BODIPY Copolymer as an Effective Agent for Photodynamic Antimicrobial Inactivation. J Phys Chem B 2021; 125:1550-1557. [PMID: 33538173 PMCID: PMC8279490 DOI: 10.1021/acs.jpcb.0c09634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 01/15/2021] [Indexed: 12/24/2022]
Abstract
We report the synthesis and photophysical properties of a neutral BODIPY photosensitizing copolymer (poly-8-(4-hydroxymethylphenyl)-4,4-difluoro-2,6-diethynyl-4-bora-3a,4a-diaza-s-indacene) containing ethynylbenzene links between the BODIPY units. The copolymer absorbs further towards the red in the UV-vis spectrum compared to the BODIPY precursor. Photolysis of the polymer produces a singlet excited state which crosses to the triplet surface in less than 300 ps. This triplet state was used to form singlet oxygen with a quantum yield of 0.34. The steps leading to population of the triplet state were studied using time-resolved spectroscopic techniques spanning the pico- to nanosecond timescales. The ability of the BODIPY polymer to generate a biocidal species for bactericidal activity in both solution- and coating-based studies was assessed. When the BODIPY copolymer was dropcast onto a surface, 4 log and 6 log reductions in colony forming units/ml representative of Gram-positive and Gram-negative bacteria, respectively, under illumination at 525 nm were observed. The potent broad-spectrum antimicrobial activity of a neutral metal-free copolymer when exposed to visible light conditions may have potential clinical applications in infection management.
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Affiliation(s)
- Aoibhín
A. Cullen
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | - Ashwene Rajagopal
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
- Department
of Clinical Microbiology, RCSI Education and Research, Royal College of Surgeons in Ireland, Beaumont Hospital, Beaumont, Dublin 9, Ireland
| | - Katharina Heintz
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | - Andreas Heise
- Department
of Chemistry, Science Foundation Ireland (SFI) Centre for Research
in Medical Devices (CURAM), The Science Foundation Ireland (SFI) Advanced
Materials and Bioengineering Research Centre (AMBER), RCSI University of Medicine and Health Science, 123 St. Stephen’s Green, Dublin 2, Ireland
| | - Robert Murphy
- Department
of Chemistry, Science Foundation Ireland (SFI) Centre for Research
in Medical Devices (CURAM), The Science Foundation Ireland (SFI) Advanced
Materials and Bioengineering Research Centre (AMBER), RCSI University of Medicine and Health Science, 123 St. Stephen’s Green, Dublin 2, Ireland
| | - Igor V. Sazanovich
- Central
Laser Facility, Science & Technology Facilities Council, Research
Complex at Harwell, Rutherford Appleton
Laboratory, Didcot OX11 0QX, U.K.
| | - Gregory M. Greetham
- Central
Laser Facility, Science & Technology Facilities Council, Research
Complex at Harwell, Rutherford Appleton
Laboratory, Didcot OX11 0QX, U.K.
| | - Michael Towrie
- Central
Laser Facility, Science & Technology Facilities Council, Research
Complex at Harwell, Rutherford Appleton
Laboratory, Didcot OX11 0QX, U.K.
| | - Conor Long
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | - Deirdre Fitzgerald-Hughes
- Department
of Clinical Microbiology, RCSI Education and Research, Royal College of Surgeons in Ireland, Beaumont Hospital, Beaumont, Dublin 9, Ireland
| | - Mary T. Pryce
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
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Magal P, Webb GF, Wu Y. A spatial model of honey bee colony collapse due to pesticide contamination of foraging bees. J Math Biol 2020; 80:2363-2393. [PMID: 32415373 DOI: 10.1007/s00285-020-01498-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 03/16/2020] [Indexed: 10/24/2022]
Abstract
We develop a model of honey bee colony collapse based on contamination of forager bees in pesticide contaminated spatial environments. The model consists of differential and difference equations for the spatial distributions of the uncontaminated and contaminated forager bees. A key feature of the model is incorporation of the return to the hive each day of forager bees. The model quantifies colony collapse in terms of two significant properties of honey bee colonies: (1) the fraction of contaminated forager bees that fail to return home due to pesticide contamination, and (2) the fraction of forager bees in the total forager bee population that return to the sites visited on the previous day. If the fraction of contaminated foragers failing to return home is high, then the total population falls below a critical threshold and colony collapse ensues. If the fraction of all foragers that return to previous foraging sites is high, then foragers who visit contaminated sites multiple times have a higher probability of becoming contaminated, and colony collapse ensues. This quantification of colony collapse provides guidance for implementing measures for its avoidance.
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Affiliation(s)
- P Magal
- Université de Bordeaux, Bordeaux, France
| | - G F Webb
- Vanderbilt University, Nashville, TN, USA.
| | - Yixiang Wu
- Vanderbilt University, Nashville, TN, USA
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Affiliation(s)
- Qingyun Diao
- Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Haidian District, Beijing, P. R. China
- Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Haidian District, Beijing, P. R. China
| | - Chunsheng Hou
- Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Haidian District, Beijing, P. R. China
- Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Haidian District, Beijing, P. R. China
- * E-mail:
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