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Moore JV, Wylie MP, Andrews GP, McCoy CP. Photosensitiser-incorporated microparticles for photodynamic inactivation of bacteria. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2023; 241:112671. [PMID: 36870247 DOI: 10.1016/j.jphotobiol.2023.112671] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/27/2023] [Accepted: 02/17/2023] [Indexed: 03/06/2023]
Abstract
Antimicrobial resistance is an ever-growing global concern, making the development of alternative antimicrobial agents and techniques an urgent priority to protect public health. Antimicrobial photodynamic therapy (aPDT) is one such promising alternative, which harnesses the cytotoxic action of reactive oxygen species (ROS) generated upon irradiation of photosensitisers (PSs) with visible light to destroy microorganisms. In this study we report a convenient and facile method to produce highly photoactive antimicrobial microparticles, exhibiting minimal PS leaching, and examine the effect of particle size on antimicrobial activity. A ball milling technique produced a range of sizes of anionic p(HEMA-co-MAA) microparticles, providing large surface areas available for electrostatic attachment of the cationic PS, Toluidine Blue O (TBO). The TBO-incorporated microparticles showed a size-dependent effect on antimicrobial activity, with a decrease in microparticle size resulting in an increase in the bacterial reductions achieved when irradiated with red light. The >6 log10Pseudomonas aeruginosa and Staphylococcus aureus reductions (>99.9999%) achieved within 30 and 60 min, respectively, by TBO-incorporated >90 μm microparticles were attributed to the cytotoxic action of the ROS generated by TBO molecules bound to the microparticles, with no PS leaching from these particles detected over this timeframe. TBO-incorporated microparticles capable of significantly reducing the bioburden of solutions with short durations of low intensity red light irradiation and minimal leaching present an attractive platform for various antimicrobial applications.
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Affiliation(s)
- Jessica V Moore
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Matthew P Wylie
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Gavin P Andrews
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Colin P McCoy
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
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2
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Bäumler W, Eckl D, Holzmann T, Schneider-Brachert W. Antimicrobial coatings for environmental surfaces in hospitals: a potential new pillar for prevention strategies in hygiene. Crit Rev Microbiol 2021; 48:531-564. [PMID: 34699296 DOI: 10.1080/1040841x.2021.1991271] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Recent reports provide evidence that contaminated healthcare environments represent major sources for the acquisition and transmission of pathogens. Antimicrobial coatings (AMC) may permanently and autonomously reduce the contamination of such environmental surfaces complementing standard hygiene procedures. This review provides an overview of the current status of AMC and the demands to enable a rational application of AMC in health care settings. Firstly, a suitable laboratory test norm is required that adequately quantifies the efficacy of AMC. In particular, the frequently used wet testing (e.g. ISO 22196) must be replaced by testing under realistic, dry surface conditions. Secondly, field studies should be mandatory to provide evidence for antimicrobial efficacy under real-life conditions. The antimicrobial efficacy should be correlated to the rate of nosocomial transmission at least. Thirdly, the respective AMC technology should not add additional bacterial resistance development induced by the biocidal agents and co- or cross-resistance with antibiotic substances. Lastly, the biocidal substances used in AMC should be safe for humans and the environment. These measures should help to achieve a broader acceptance for AMC in healthcare settings and beyond. Technologies like the photodynamic approach already fulfil most of these AMC requirements.
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Affiliation(s)
- Wolfgang Bäumler
- Department of Dermatology, University Hospital, Regensburg, Germany
| | - Daniel Eckl
- Department of Microbiology, University of Regensburg, Regensburg, Germany
| | - Thomas Holzmann
- Department of Infection Control and Infectious Diseases, University Hospital, Regensburg, Germany
| | - Wulf Schneider-Brachert
- Department of Infection Control and Infectious Diseases, University Hospital, Regensburg, Germany
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3
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Di Battista A, Nicolaides C, Georgiou O. Modelling disease transmission from touchscreen user interfaces. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210625. [PMID: 34350020 PMCID: PMC8316822 DOI: 10.1098/rsos.210625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/10/2021] [Indexed: 06/13/2023]
Abstract
The extensive use of touchscreens for all manner of human-computer interactions has made them plausible instruments of touch-mediated disease transmission. To that end, we employ stochastic simulations to model human-fomite interaction with a distinct focus on touchscreen interfaces. The timings and frequency of interactions from within a closed population of infectious and susceptible individuals was modelled using a queuing network. A pseudo-reproductive number R was used to compare outcomes under various parameter conditions. We then apply the simulation to a specific real-world scenario; namely that of airport self-check-in and baggage drop. A counterintuitive result was that R decreased with increased touch rates required for touchscreen interaction. Additionally, as one of few parameters to be controlled, the rate of cleaning/disinfecting screens plays an essential role in mitigating R, though alternative technological strategies could prove more effective. The simulation model developed provides a foundation for future advances in more sophisticated fomite disease-transmission modelling.
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Affiliation(s)
| | - Christos Nicolaides
- School of Economics and Management, University of Cyprus, Nicosia, Cyprus
- Nireas Research Center, University of Cyprus, Nicosia, Cyprus
- Initiative on the Digital Economy, MIT Sloan School of Management, Cambridge MA, USA
| | - Orestis Georgiou
- Ultraleap Ltd, Bristol, UK
- Department of Electrical and Computer Engineering, University of Cyprus, Nicosia, Cyprus
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Kanth S, Nagaraja A, Puttaiahgowda YM. Polymeric approach to combat drug-resistant methicillin-resistant Staphylococcus aureus. JOURNAL OF MATERIALS SCIENCE 2021; 56:7265-7285. [PMID: 33518799 PMCID: PMC7831626 DOI: 10.1007/s10853-021-05776-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 01/03/2021] [Indexed: 05/10/2023]
Abstract
ABSTRACT The current global death rate has threatened humans due to increase in deadly unknown infections caused by pathogenic microorganisms. On the contrary, the emergence of multidrug-resistant bacteria is also increasing which is leading to elevated lethality rate worldwide. Development of drug-resistant bacteria has become one of the daunting global challenges due to failure in approaching to combat against them. Methicillin-resistant Staphylococcus aureus (MRSA) is one of those drug-resistant bacteria which has led to increase in global mortality rate causing various lethal infections. Polymer synthesis can be one of the significant approaches to combat MRSA by fabricating polymeric coatings to prevent the spread of infections. This review provides last decade information in the development of various polymers against MRSA. GRAPHICAL ABSTRACT
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Affiliation(s)
- Shreya Kanth
- Department of Chemistry, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104 India
| | - Akshatha Nagaraja
- Department of Chemistry, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104 India
| | - Yashoda Malgar Puttaiahgowda
- Department of Chemistry, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104 India
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Wylie MP, Irwin NJ, Howard D, Heydon K, McCoy CP. Hot-melt extrusion of photodynamic antimicrobial polymers for prevention of microbial contamination. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 214:112098. [PMID: 33276276 DOI: 10.1016/j.jphotobiol.2020.112098] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 11/17/2020] [Accepted: 11/23/2020] [Indexed: 01/31/2023]
Abstract
Infectious disease outbreaks within healthcare facilities can exacerbate patient illness and, in some cases, can be fatal. Contaminated surfaces and medical devices can act as a reservoir for transmission of pathogens and have been linked to the rising incidence of healthcare-acquired infections. Antimicrobial surfaces can reduce microbial contamination and transmission and have emerged as a crucial component in healthcare infection control in recent years. The aim of this study was to manufacture antimicrobial polymer surfaces containing the photosensitiser, toluidine blue O (TBO), using hot-melt extrusion (HME). Several concentrations of TBO were combined with a range of medically relevant polymers via HME. TBO-polymer extrudates displayed no significant differences in thermal properties and surface wettability relative to non-loaded polymers. Minimal leaching of TBO from the surface was confirmed through in vitro release studies. Antibacterial activity was observed to vary according to the polymer and concentration of incorporated TBO, with PEBAX® polymers modified with 0.1% w/w TBO demonstrating promising reductions of >99.9% in viable bacterial adherence of a range of common nosocomial pathogens, including Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii and Escherichia coli. This study demonstrates the use of HME as a facile alternative method to common encapsulation strategies for the production of light-activated antimicrobial polymer surfaces. This method can be easily translated to large-scale manufacture and, in addition, the polymers constitute promising antimicrobial base materials for the rapidly growing additive manufacturing industries.
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Affiliation(s)
- Matthew P Wylie
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Nicola J Irwin
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - David Howard
- IPC - Innovative Polymer Compounds, Midlands Gateway Business Park, Streamstown Road, Kilbeggan, Co. Westmeath, Ireland
| | - Katie Heydon
- IPC - Innovative Polymer Compounds, Midlands Gateway Business Park, Streamstown Road, Kilbeggan, Co. Westmeath, Ireland
| | - Colin P McCoy
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
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Dharmaratne P, Sapugahawatte DN, Wang B, Chan CL, Lau KM, Lau CB, Fung KP, Ng DK, Ip M. Contemporary approaches and future perspectives of antibacterial photodynamic therapy (aPDT) against methicillin-resistant Staphylococcus aureus (MRSA): A systematic review. Eur J Med Chem 2020; 200:112341. [PMID: 32505848 DOI: 10.1016/j.ejmech.2020.112341] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 04/15/2020] [Accepted: 04/15/2020] [Indexed: 11/19/2022]
Abstract
The high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) causing skin and soft tissue infections in both the community and healthcare settings challenges the limited options of effective antibiotics and motivates the search for alternative therapeutic solutions, such as antibacterial photodynamic therapy (aPDT). While many publications have described the promising anti-bacterial activities of PDT in vitro, its applications in vivo and in the clinic have been very limited. This limited availability may in part be due to variabilities in the selected photosensitizing agents (PS), the variable testing conditions used to examine anti-bacterial activities and their effectiveness in treating MRSA infections. We thus sought to systematically review and examine the evidence from existing studies on aPDT associated with MRSA and to critically appraise its current state of development and areas to be addressed in future studies. In 2018, we developed and registered a review protocol in the International Prospective Register of Systematic Reviews (PROSPERO) with registration No: CRD42018086736. Three bibliographical databases were consulted (PUBMED, MEDLINE, and EMBASE), and a total of 113 studies were included in this systematic review based on our eligibility criteria. Many variables, such as the use of a wide range of solvents, pre-irradiation times, irradiation times, light sources and light doses, have been used in the methods reported by researchers, which significantly affect the inter-study comparability and results. On another note, new approaches of linking immunoglobulin G (IgG), antibodies, efflux pump inhibitors, and bacteriophages with photosensitizers (PSs) and the incorporation of PSs into nano-scale delivery systems exert a direct effect on improving aPDT. Enhanced activities have also been achieved by optimizing the physicochemical properties of the PSs, such as the introduction of highly lipophilic, poly-cationic and site-specific modifications of the compounds. However, few in vivo studies (n = 17) have been conducted to translate aPDT into preclinical studies. We anticipate that further standardization of the experimental conditions and assessing the efficacy in vivo would allow this technology to be further applied in preclinical trials, so that aPDT would develop to become a sustainable, alternative therapeutic option against MRSA infection in the future.
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Affiliation(s)
- Priyanga Dharmaratne
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (SAR), China.
| | | | - Baiyan Wang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (SAR), China.
| | - Chung Lap Chan
- Institute of Chinese Medicine and State Key Laboratory of Research on Bioactivities and Clinical Applications of Medicinal Plants, The Chinese University of Hong Kong, China.
| | - Kit-Man Lau
- Institute of Chinese Medicine and State Key Laboratory of Research on Bioactivities and Clinical Applications of Medicinal Plants, The Chinese University of Hong Kong, China.
| | - Clara Bs Lau
- Institute of Chinese Medicine and State Key Laboratory of Research on Bioactivities and Clinical Applications of Medicinal Plants, The Chinese University of Hong Kong, China.
| | - Kwok Pui Fung
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (SAR), China; CUHK-Zhejiang University Joint Laboratory on Natural Products and Toxicology Research, China.
| | - Dennis Kp Ng
- Department of Chemistry, Faculty of Science, The Chinese University of Hong Kong, Hong Kong (SAR), China
| | - Margaret Ip
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (SAR), China; Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
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Chen W, Chen J, Li L, Wang X, Wei Q, Ghiladi RA, Wang Q. Wool/Acrylic Blended Fabrics as Next-Generation Photodynamic Antimicrobial Materials. ACS APPLIED MATERIALS & INTERFACES 2019; 11:29557-29568. [PMID: 31356046 DOI: 10.1021/acsami.9b09625] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The adoption of self-sterilizing materials to reduce infection transmission in hospitals and related healthcare facilities has been hampered by the availability of scalable, cost-effective, and potent antimicrobial textiles. Here, we investigated whether photodynamic materials comprising photosensitizer-embedded wool/acrylic blends were able to mediate the photodynamic inactivation of Gram-positive and Gram-negative bacteria. A small library of wool/acrylic (W/A) blended fabrics was constructed wherein the wool fibers were embedded with rose Bengal (RB) as a photosensitizer and the acrylic fibers were dyed with a traditional cationic yellow X-8GL dye, thereby enabling a broader color palette than was achievable with a single photosensitizer. The resultant photodynamic materials were characterized by physical (SEM, DSC, TGA, tensile strength), spectroscopic (fluorescence), colorimetric (K/S and CIELab values), and color fastness (against rubbing, washing) studies, and their photooxidation of the model substrate potassium iodide demonstrated the ability of these materials to generate microbicidal reactive oxygen species (i.e., singlet oxygen) upon illumination. Our best results yielded the photodynamic inactivation of Gram-positive S. aureus (99.98%) and B. subtilis (99.993%) by ∼4 log units upon illumination with visible light (60 min; 65 ± 5 mW/cm2; λ ≥ 420 nm), although more modest activity was observed against Gram-negative P. aeruginosa and E. coli (1-2 log units pathogen reduction). While there were no statistically significant differences for dual-dyed materials that were produced through either sequential or simultaneous dyeing steps, it was noted that high loadings of the cationic yellow X-8GL dye did inhibit the antimicrobial activity of the RB photosensitizer, with the dual-dyed materials able to mediate a 2.9 log unit reduction against S. aureus at a 1% o.w.f X-8GL loading. These findings indicate that the antimicrobial photodynamic inactivation of dual-dyed materials is independent of the dyeing process itself, yet exhibits limitations on the loading of the traditional dye with regards to the activity of the photosensitizer. Taken together, the results suggest the feasibility of photosensitizer-embedded blended fabrics produced through a one-step dyeing process as a low-cost and scalable method for creating effective self-disinfecting textiles for infection prevention, and whose inclusion of a second traditional dye for color variation will further benefit their adoption from a commercial standpoint.
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Affiliation(s)
- Wangbingfei Chen
- Key Laboratory of Eco-Textiles, Ministry of Education , Jiangnan University , Wuxi 214122 , China
| | - Jiang Chen
- Key Laboratory of Eco-Textiles, Ministry of Education , Jiangnan University , Wuxi 214122 , China
| | - Ling Li
- Key Laboratory of Eco-Textiles, Ministry of Education , Jiangnan University , Wuxi 214122 , China
| | - Xinyi Wang
- Key Laboratory of Eco-Textiles, Ministry of Education , Jiangnan University , Wuxi 214122 , China
| | - Qufu Wei
- Key Laboratory of Eco-Textiles, Ministry of Education , Jiangnan University , Wuxi 214122 , China
| | - Reza A Ghiladi
- Key Laboratory of Eco-Textiles, Ministry of Education , Jiangnan University , Wuxi 214122 , China
- Department of Chemistry , North Carolina State University , Raleigh , North Carolina 27695 , United States
| | - Qingqing Wang
- Key Laboratory of Eco-Textiles, Ministry of Education , Jiangnan University , Wuxi 214122 , China
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Kováčová M, Marković ZM, Humpolíček P, Mičušík M, Švajdlenková H, Kleinová A, Danko M, Kubát P, Vajďák J, Capáková Z, Lehocký M, Münster L, Todorović Marković BM, Špitalský Z. Carbon Quantum Dots Modified Polyurethane Nanocomposite as Effective Photocatalytic and Antibacterial Agents. ACS Biomater Sci Eng 2018; 4:3983-3993. [PMID: 33418799 DOI: 10.1021/acsbiomaterials.8b00582] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Development of new types of antibacterial coatings or nanocomposites is of great importance due to widespread multidrug-resistant infections including bacterial infections. Herein, we investigated biocompatibility as well as structural, photocatalytic, and antibacterial properties of photoactive hydrophobic carbon quantum dots/polyurethane nanocomposite. The swell-encapsulation-shrink method was applied for production of these nanocomposites. Hydrophobic carbon quantum dots/polyurethane nanocomposites were found to be highly effective generator of singlet oxygen upon irradiation by low-power blue light. Analysis of conducted antibacterial tests on Staphyloccocus aureus and Escherichia coli showed 5-log bactericidal effect of these nanocomposites within 60 min of irradiation. Very powerful degradation of dye (rose bengal) was observed within 180 min of blue light irradiation of the nanocomposites. Biocompatibility studies revealed that nanocomposites were not cytotoxic against mouse embryonic fibroblast cell line, whereas they showed moderate cytotoxicity toward adenocarcinomic human epithelial cell line. Minor hemolytic effect of these nanocomposites toward red blood cells was revealed.
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Affiliation(s)
- Mária Kováčová
- Polymer Institute, Slovak Academy of Sciences, Dúbravská cestá 9, 84541 Bratislava, Slovakia
| | - Zoran M Marković
- Polymer Institute, Slovak Academy of Sciences, Dúbravská cestá 9, 84541 Bratislava, Slovakia.,Vinča Institute of Nuclear Sciences, University of Belgrade, Mike Alasa 12-14, 11001 Belgrade, Serbia
| | - Petr Humpolíček
- Centre of Polymer Systems, Tomas Bata University in Zlín, Trida Tomase Bati, 5678 Zlín, Czech Republic
| | - Matej Mičušík
- Polymer Institute, Slovak Academy of Sciences, Dúbravská cestá 9, 84541 Bratislava, Slovakia
| | - Helena Švajdlenková
- Polymer Institute, Slovak Academy of Sciences, Dúbravská cestá 9, 84541 Bratislava, Slovakia
| | - Angela Kleinová
- Polymer Institute, Slovak Academy of Sciences, Dúbravská cestá 9, 84541 Bratislava, Slovakia
| | - Martin Danko
- Polymer Institute, Slovak Academy of Sciences, Dúbravská cestá 9, 84541 Bratislava, Slovakia
| | - Pavel Kubát
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, 182 23 Praha 8, Czech Republic
| | - Jan Vajďák
- Centre of Polymer Systems, Tomas Bata University in Zlín, Trida Tomase Bati, 5678 Zlín, Czech Republic
| | - Zdenka Capáková
- Centre of Polymer Systems, Tomas Bata University in Zlín, Trida Tomase Bati, 5678 Zlín, Czech Republic
| | - Marián Lehocký
- Centre of Polymer Systems, Tomas Bata University in Zlín, Trida Tomase Bati, 5678 Zlín, Czech Republic
| | - Lukaš Münster
- Centre of Polymer Systems, Tomas Bata University in Zlín, Trida Tomase Bati, 5678 Zlín, Czech Republic
| | | | - Zdeno Špitalský
- Polymer Institute, Slovak Academy of Sciences, Dúbravská cestá 9, 84541 Bratislava, Slovakia
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Peddinti BST, Scholle F, Ghiladi RA, Spontak RJ. Photodynamic Polymers as Comprehensive Anti-Infective Materials: Staying Ahead of a Growing Global Threat. ACS APPLIED MATERIALS & INTERFACES 2018; 10:25955-25959. [PMID: 30044089 DOI: 10.1021/acsami.8b09139] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
To combat the global threat posed by surface-adhering pathogens that are becoming increasingly drug-resistant, we explore the anti-infective efficacy of bulk thermoplastic elastomer films containing ∼1 wt % zinc-tetra(4- N-methylpyridyl)porphine (ZnTMPyP4+), a photoactive antimicrobial that utilizes visible light to generate singlet oxygen. This photodynamic polymer is capable of inactivating five bacterial strains and two viruses with at least 99.89% and 99.95% success, respectively, after exposure to noncoherent light for 60 min. Unlike other anti-infective methodologies commonly requiring oxidizing chemicals, carcinogenic radiation, or toxic nanoparticles, our approach is nonspecific and safe/nontoxic, and sustainably relies on the availability of just oxygen and visible light.
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Sigusch BW, Dietsch S, Berg A, Voelpel A, Guellmar A, Rabe U, Schnabelrauch M, Steen D, Gitter B, Albrecht V, Watts DC, Kranz S. Antimicrobial photodynamic active biomaterials for periodontal regeneration. Dent Mater 2018; 34:1542-1554. [PMID: 29970234 DOI: 10.1016/j.dental.2018.06.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/18/2018] [Accepted: 06/18/2018] [Indexed: 02/09/2023]
Abstract
OBJECTIVE Biomaterials for periodontal regeneration may have insufficient mechanical and antimicrobial properties or are difficult to apply under clinical conditions. The aim of the present study was to develop a polymeric bone grafting material of suitable physical appearance and antimicrobial photodynamic activity. METHODS Two light curable biomaterials based on urethane dimethacrylate (BioM1) and a tri-armed oligoester-urethane methacrylate (BioM2) that additionally contained a mixture of β-tricalcium phosphate microparticles and 20wt% photosensitizer mTHPC (PS) were fabricated and analyzed by their compressive strength, flexural strength and modulus of elasticity. Cytotoxicity was observed by incubating eluates and in direct-contact to MC3T3-E1 cells. Antimicrobial activity was ascertained on Porphyromonas gingivalis and Enterococcus faecalis upon illumination with laser light (652nm, 1×100J/cm2, 2×100J/cm2). RESULTS The compressive strength, flexural strength and elastic modulus were, respectively, 311.73MPa, 22.81MPa and 318.85MPa for BioM1+PS and 742.37MPa, 7.58MPa and 406.23MPa for BioM2+PS. Both materials did not show any cytotoxic behavior. Single laser-illumination (652nm) caused total suppression of P. gingivalis (BioM2+PS), while repeated irradiation reduced E. faecalis by 3.7 (BioM1+PS) and 3.1 (BioM2+PS) log-counts. SIGNIFICANCE Both materials show excellent mechanical and cytocompatible properties. In addition, irradiation with 652nm induced significant bacterial suppression. The manufactured biomaterials might enable a more efficient cure of periodontal bone lesions. Due to the mechanical properties functional stability might be increased. Further, the materials are antimicrobial upon illumination with light that enables a trans-mucosal eradication of residual pathogens.
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Affiliation(s)
- B W Sigusch
- Department of Conservative Dentistry and Periodontology, University Hospitals Jena, An der alten Post 4, 07743 Jena, Germany
| | - S Dietsch
- Department of Conservative Dentistry and Periodontology, University Hospitals Jena, An der alten Post 4, 07743 Jena, Germany
| | - A Berg
- Biomaterials Department, INNOVENT e.V. Pruessingstrasse 27 B, 07745 Jena, Germany
| | - A Voelpel
- Department of Conservative Dentistry and Periodontology, University Hospitals Jena, An der alten Post 4, 07743 Jena, Germany
| | - A Guellmar
- Department of Conservative Dentistry and Periodontology, University Hospitals Jena, An der alten Post 4, 07743 Jena, Germany
| | - U Rabe
- Department of Conservative Dentistry and Periodontology, University Hospitals Jena, An der alten Post 4, 07743 Jena, Germany
| | - M Schnabelrauch
- Biomaterials Department, INNOVENT e.V. Pruessingstrasse 27 B, 07745 Jena, Germany
| | - D Steen
- biolitec research GmbH, Otto-Schott-Str. 15, 07745 Jena, Germany
| | - B Gitter
- biolitec research GmbH, Otto-Schott-Str. 15, 07745 Jena, Germany
| | - V Albrecht
- biolitec research GmbH, Otto-Schott-Str. 15, 07745 Jena, Germany
| | - D C Watts
- University of Manchester, School of Medical Sciences,Oxford Road, M13 9PL Manchester, UK
| | - S Kranz
- Department of Conservative Dentistry and Periodontology, University Hospitals Jena, An der alten Post 4, 07743 Jena, Germany.
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Pucelik B, Paczyński R, Dubin G, Pereira MM, Arnaut LG, Dąbrowski JM. Properties of halogenated and sulfonated porphyrins relevant for the selection of photosensitizers in anticancer and antimicrobial therapies. PLoS One 2017; 12:e0185984. [PMID: 29016698 PMCID: PMC5634595 DOI: 10.1371/journal.pone.0185984] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 09/24/2017] [Indexed: 01/10/2023] Open
Abstract
The impact of substituents on the photochemical and biological properties of tetraphenylporphyrin-based photosensitizers for photodynamic therapy of cancer (PDT) as well as photodynamic inactivation of microorganisms (PDI) was examined. Spectroscopic and physicochemical properties were related with therapeutic efficacy in PDT of cancer and PDI of microbial cells in vitro. Less polar halogenated, sulfonamide porphyrins were most readily taken up by cells compared to hydrophilic and anionic porphyrins. The uptake and PDT of a hydrophilic porphyrin was significantly enhanced with incorporation in polymeric micelles (Pluronic L121). Photodynamic inactivation studies were performed against Gram-positive (S. aureus, E. faecalis), Gram-negative bacteria (E. coli, P. aeruginosa, S. marcescens) and fungal yeast (C. albicans). We observed a 6 logs reduction of S. aureus after irradiation (10 J/cm2) in the presence of 20 μM of hydrophilic porphyrin, but this was not improved with incorporation in Pluronic L121. A 2–3 logs reduction was obtained for E. coli using similar doses, and a decrease of 3–4 logs was achieved for C. albicans. Rational substitution of tetraphenylporphyrins improves their photodynamic properties and informs on strategies to obtain photosensitizers for efficient PDT and PDI. However, the design of the photosensitizers must be accompanied by the development of tailored drug formulations.
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Affiliation(s)
- Barbara Pucelik
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, Krakow, Poland
| | - Robert Paczyński
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Grzegorz Dubin
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | | | - Luis G. Arnaut
- Chemistry Department, University of Coimbra, Coimbra, Portugal
| | - Janusz M. Dąbrowski
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, Krakow, Poland
- * E-mail:
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12
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Inactivation and changes in metabolic profile of selected foodborne bacteria by 460 nm LED illumination. Food Microbiol 2017; 63:12-21. [DOI: 10.1016/j.fm.2016.10.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/28/2016] [Accepted: 10/20/2016] [Indexed: 01/17/2023]
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13
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Morozov M, Carmieli R, Lahav M, van der Boom ME. Light-Activated Antibacterial Nanoscale Films: Metallo-Organics for Catalytic Generation of Chemically Accessible Singlet-Oxygen in Water. ChemistrySelect 2017. [DOI: 10.1002/slct.201601724] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Michael Morozov
- Department of Organic Chemistry; Weizmann Institute of Science; 7610001 Rehovot Israel
| | - Raanan Carmieli
- Department of Chemical Research Support; Weizmann Institute of Science; 7610001 Rehovot Israel
| | - Michal Lahav
- Department of Organic Chemistry; Weizmann Institute of Science; 7610001 Rehovot Israel
| | - Milko E. van der Boom
- Department of Organic Chemistry; Weizmann Institute of Science; 7610001 Rehovot Israel
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14
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Macdonald TJ, Wu K, Sehmi SK, Noimark S, Peveler WJ, du Toit H, Voelcker NH, Allan E, MacRobert AJ, Gavriilidis A, Parkin IP. Thiol-Capped Gold Nanoparticles Swell-Encapsulated into Polyurethane as Powerful Antibacterial Surfaces Under Dark and Light Conditions. Sci Rep 2016; 6:39272. [PMID: 27982122 PMCID: PMC5159832 DOI: 10.1038/srep39272] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 11/14/2016] [Indexed: 12/20/2022] Open
Abstract
A simple procedure to develop antibacterial surfaces using thiol-capped gold nanoparticles (AuNPs) is shown, which effectively kill bacteria under dark and light conditions. The effect of AuNP size and concentration on photo-activated antibacterial surfaces is reported and we show significant size effects, as well as bactericidal activity with crystal violet (CV) coated polyurethane. These materials have been proven to be powerful antibacterial surfaces against both Gram-positive and Gram-negative bacteria. AuNPs of 2, 3 or 5 nm diameter were swell-encapsulated into PU before a coating of CV was applied (known as PU-AuNPs-CV). The antibacterial activity of PU-AuNPs-CV samples was tested against Staphylococcus aureus and Escherichia coli as representative Gram-positive and Gram-negative bacteria under dark and light conditions. All light conditions in this study simulated a typical white-light hospital environment. This work demonstrates that the antibacterial activity of PU-AuNPs-CV samples and the synergistic enhancement of photoactivity of triarylmethane type dyes is highly dependent on nanoparticle size and concentration. The most powerful PU-AuNPs-CV antibacterial surfaces were achieved using 1.0 mg mL-1 swell encapsulation concentrations of 2 nm AuNPs. After two hours, Gram-positive and Gram-negative bacteria were reduced to below the detection limit (>4 log) under dark and light conditions.
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Affiliation(s)
- Thomas J. Macdonald
- Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom
| | - Ke Wu
- Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom
| | - Sandeep K. Sehmi
- Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom
| | - Sacha Noimark
- Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom
| | - William J. Peveler
- Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom
| | - Hendrik du Toit
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, United Kingdom
| | - Nicolas H. Voelcker
- ARC Centre of Excellence for Convergent Bio-Nano Science and Technology, Future Industries Institute, University of South Australia, Mawson Lakes, 5095, Australia
| | - Elaine Allan
- Division of Microbial Diseases, UCL Eastman Dental Institute, University College London, 256 Grays Inn Road, London, WC1X 8LD, United Kingdom
| | - Alexander J. MacRobert
- UCL Division of Surgery and Interventional Science, Royal Free Campus, Rowland Hill Street, London, NW3 2PF, United Kingdom
| | - Asterios Gavriilidis
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, United Kingdom
| | - Ivan P. Parkin
- Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ, United Kingdom
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15
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Wainwright M, Maisch T, Nonell S, Plaetzer K, Almeida A, Tegos GP, Hamblin MR. Photoantimicrobials-are we afraid of the light? THE LANCET. INFECTIOUS DISEASES 2016; 17:e49-e55. [PMID: 27884621 PMCID: PMC5280084 DOI: 10.1016/s1473-3099(16)30268-7] [Citation(s) in RCA: 419] [Impact Index Per Article: 52.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 06/28/2016] [Accepted: 07/14/2016] [Indexed: 02/07/2023]
Abstract
Although conventional antimicrobial drugs have been viewed as miraculous cure-alls for the past 80 years, increasing antimicrobial drug resistance requires a major and rapid intervention. However, the development of novel but still conventional systemic antimicrobial agents, having only a single mode or site of action, will not alleviate the situation because it is probably only a matter of time until any such agents will also become ineffective. To continue to produce new agents based on this notion is unacceptable, and there is an increasing need for alternative approaches to the problem. By contrast, light-activated molecules called photoantimicrobials act locally via the in-situ production of highly reactive oxygen species, which simultaneously attack various biomolecular sites in the pathogenic target and therefore offer both multiple and variable sites of action. This non-specificity at the target circumvents conventional mechanisms of resistance and inhibits the development of resistance to the agents themselves. Photoantimicrobial therapy is safe and easy to implement and, unlike conventional agents, the activity spectrum of photoantimicrobials covers bacteria, fungi, viruses, and protozoa. However, clinical trials of these new, truly broad-spectrum, and minimally toxic agents have been few, and the funding for research and development is almost non-existent. Photoantimicrobials constitute one of the few ways forward through the morass of drug-resistant infectious disease and should be fully explored. In this Personal View, we raise awareness of the novel photoantimicrobial technologies that offer a viable alternative to conventional drugs in many relevant application fields, and could thus slow the pace of resistance development.
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Affiliation(s)
- Mark Wainwright
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK.
| | - Tim Maisch
- Department of Dermatology, University Medical Center Regensburg, Regensburg, Germany
| | - Santi Nonell
- Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain
| | - Kristjan Plaetzer
- Laboratory of Photodynamic Inactivation of Microorganisms, Department of Materials Science and Physics, University of Salzburg, Salzburg, Austria
| | - Adelaide Almeida
- Department of Biology, and Centre for Environmental and Marine (CESAM) Studies, University of Aveiro, Aveiro, Portugal
| | - George P Tegos
- The Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA; Department of Dermatology, Harvard Medical School, Boston, MA, USA
| | - Michael R Hamblin
- The Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA; Department of Dermatology, Harvard Medical School, Boston, MA, USA; Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
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16
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Henke P, Kirakci K, Kubát P, Fraiberk M, Forstová J, Mosinger J. Antibacterial, Antiviral, and Oxygen-Sensing Nanoparticles Prepared from Electrospun Materials. ACS APPLIED MATERIALS & INTERFACES 2016; 8:25127-36. [PMID: 27589368 DOI: 10.1021/acsami.6b08234] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
A simple nanoprecipitation method was used for preparation of stable photoactive polystyrene nanoparticles (NPs, diameter 30 ± 10 nm) from sulfonated electrospun polystyrene nanofiber membranes with encapsulated 5,10,15,20-tetraphenylporphyrin (TPP) or platinum octaethylporphyrin (Pt-OEP). The NPs prepared with TPP have strong antibacterial and antiviral properties and can be applied to the photooxidation of external substrates based on photogenerated singlet oxygen. In contrast to nanofiber membranes, which have limited photooxidation ability near the surface, NPs are able to travel toward target species/structures. NPs with Pt-OEP were used for oxygen sensing in aqueous media, and they presented strong linear responses to a broad range of oxygen concentrations. The nanofiber membranes can be applied not only as a source of NPs but also as an effective filter for their removal from solution.
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Affiliation(s)
- Petr Henke
- Faculty of Science, Charles University in Prague , Hlavova 2030, 128 43 Prague 2, Czech Republic
| | - Kaplan Kirakci
- Institute of Inorganic Chemistry, v.v.i., Academy of Sciences of the Czech Republic , 250 68 Řež, Czech Republic
| | - Pavel Kubát
- J. Heyrovský Institute of Physical Chemistry, v.v.i., Czech Academy of Sciences , Dolejškova 3, 182 23 Praha 8, Czech Republic
| | - Martin Fraiberk
- Faculty of Science, Charles University in Prague , Hlavova 2030, 128 43 Prague 2, Czech Republic
| | - Jitka Forstová
- Faculty of Science, Charles University in Prague , Hlavova 2030, 128 43 Prague 2, Czech Republic
| | - Jiří Mosinger
- Faculty of Science, Charles University in Prague , Hlavova 2030, 128 43 Prague 2, Czech Republic
- Institute of Inorganic Chemistry, v.v.i., Academy of Sciences of the Czech Republic , 250 68 Řež, Czech Republic
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17
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Broad-Spectrum Antimicrobial Effects of Photocatalysis Using Titanium Dioxide Nanoparticles Are Strongly Potentiated by Addition of Potassium Iodide. Antimicrob Agents Chemother 2016; 60:5445-53. [PMID: 27381399 DOI: 10.1128/aac.00980-16] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 06/24/2016] [Indexed: 01/23/2023] Open
Abstract
Photocatalysis describes the excitation of titanium dioxide nanoparticles (a wide-band gap semiconductor) by UVA light to produce reactive oxygen species (ROS) that can destroy many organic molecules. This photocatalysis process is used for environmental remediation, while antimicrobial photocatalysis can kill many classes of microorganisms and can be used to sterilize water and surfaces and possibly to treat infections. Here we show that addition of the nontoxic inorganic salt potassium iodide to TiO2 (P25) excited by UVA potentiated the killing of Gram-positive bacteria, Gram-negative bacteria, and fungi by up to 6 logs. The microbial killing depended on the concentration of TiO2, the fluence of UVA light, and the concentration of KI (the best effect was at 100 mM). There was formation of long-lived antimicrobial species (probably hypoiodite and iodine) in the reaction mixture (detected by adding bacteria after light), but short-lived antibacterial reactive species (bacteria present during light) produced more killing. Fluorescent probes for ROS (hydroxyl radical and singlet oxygen) were quenched by iodide. Tri-iodide (which has a peak at 350 nm and a blue product with starch) was produced by TiO2-UVA-KI but was much reduced when methicillin-resistant Staphylococcus aureus (MRSA) cells were also present. The model tyrosine substrate N-acetyl tyrosine ethyl ester was iodinated in a light dose-dependent manner. We conclude that UVA-excited TiO2 in the presence of iodide produces reactive iodine intermediates during illumination that kill microbial cells and long-lived oxidized iodine products that kill after light has ended.
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18
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Nzambe Ta keki JK, Ouk TS, Zerrouki R, Faugeras PA, Sol V, Brouillette F. Synthesis and photobactericidal properties of a neutral porphyrin grafted onto lignocellulosic fibers. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 62:61-7. [DOI: 10.1016/j.msec.2016.01.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 11/01/2015] [Accepted: 01/11/2016] [Indexed: 02/08/2023]
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19
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Preuß A, Bornhütter T, Färber A, Schaller C, Röder B. Photodynamic inactivation of biofilm building microorganisms by photoactive facade paints. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 160:79-85. [PMID: 27101275 DOI: 10.1016/j.jphotobiol.2016.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 04/07/2016] [Accepted: 04/07/2016] [Indexed: 01/04/2023]
Abstract
This study was performed as a proof of concept for singlet oxygen generating facade paint as an alternative to conventional biocide containing facade paint for the prevention of biofilm growth on outdoor walls. Biofilms on outdoor walls cause esthetic problems and economic damage. Therefore facade paints often contain biocides. However commercially available biocides may have a series of adverse effects on living organisms as well as harmful environmental effects. Furthermore, biocides are increasingly designed to be more effective and are environmentally persistent. Thus, an eco-friendly and non-harmful to human health alternative to conventional biocides in wall color is strongly recommended. The well-known photosensitizer 5,10,15,20-tetrakis(N-methyl-4-pyridyl)-21H,23H-porphine (TMPyP) was used as an additive in a commercially available facade paint. The generation of singlet molecular oxygen was shown using time resolved 2D measurements of the singlet oxygen luminescence. The photodynamic activity of the photosensitizer in the facade paint was demonstrated by phototoxicity tests with defined mold fungi and a mixture of microorganisms harvested from native outdoor biofilms as model organisms. It was proven in general that it is possible to inhibit the growth of biofilm forming microorganisms growing on solid wall paint surfaces by the cationic photosensitizer TMPyP added to the facade paint using daylight conditions for illumination in 12h light and dark cycles.
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Affiliation(s)
- Annegret Preuß
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany.
| | - Tobias Bornhütter
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
| | - Alexander Färber
- Sto SE & Co. KGaA, Ehrenbachstraße 1, D-79780 Stühlingen, Germany
| | | | - Beate Röder
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
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20
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De Baróid ÁT, McCoy CP, Craig RA, Carson L, Andrews GP, Jones DS, Gorman SP. Optimization of singlet oxygen production from photosensitizer-incorporated, medically relevant hydrogels. J Biomed Mater Res B Appl Biomater 2015; 105:320-326. [PMID: 26505264 PMCID: PMC5244673 DOI: 10.1002/jbm.b.33562] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 10/05/2015] [Accepted: 10/11/2015] [Indexed: 11/12/2022]
Abstract
Photodynamic therapy and photodynamic antimicrobial chemotherapy are widely used, but despite this, the relationships between fluence, wavelength of irradiation and singlet oxygen (1O2) production are poorly understood. To establish the relationships between these factors in medically relevant materials, the effect of fluence on 1O2 production from a tetrakis(4‐N‐methylpyridyl)porphyrin (TMPyP)‐incorporated 2‐hydroxyethyl methacrylate: methyl methacrylate: methacrylic acid (HEMA: MMA:MAA) copolymer, a total energy of 50.48 J/cm2, was applied at varying illumination power, and times. 1O2 production was characterized using anthracene‐9,10‐dipropionic acid, disodium salt (ADPA) using a recently described method. Using two light sources, a white LED array and a white halogen source, the LED array was found to produce less 1O2 than the halogen source when the same power (over 500 − 600 nm) and time conditions were applied. Importantly, it showed that the longest wavelength Q band (590 nm) is primarily responsible for 1O2 generation, and that a linear relationship exists between increasing power and time and the production of singlet oxygen. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 320–326, 2017.
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Affiliation(s)
- Áine T De Baróid
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Colin P McCoy
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Rebecca A Craig
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Louise Carson
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Gavin P Andrews
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - David S Jones
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Sean P Gorman
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
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