UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Photoactivable Polymers Embedded with Cadmium-free Quantum Dots and Crystal Violet: Efficient Bactericidal Activity against Clinical Strains of Antibiotic-Resistant Bacteria

Owusu, E; MacRobert, AJ; Naasani, I; Parkin, IP; Allan, E; Yaghini, E; (2019) Photoactivable Polymers Embedded with Cadmium-free Quantum Dots and Crystal Violet: Efficient Bactericidal Activity against Clinical Strains of Antibiotic-Resistant Bacteria. ACS Applied Materials and Interfaces , 11 (13) pp. 12367-12378. 10.1021/acsami.9b02109. Green open access

[thumbnail of Yaghini_acsami.9b02109.pdf]
Preview
Text
Yaghini_acsami.9b02109.pdf - Accepted version

Download (798kB) | Preview

Abstract

The rising incidence of antibiotic-resistant infections from contaminated surfaces in hospitals or implanted medical devices has led to increasing interest in new antibacterial surfaces. Photoactivatable surfaces that can generate cytotoxic reactive oxygen species under exposure to ambient light is a promising approach to inactivation of surface-borne microorganisms. There is growing interest in the use of quantum dots (QDs) as light-harvesting agents for photobactericidal applications but the cadmium in commonly used QDs will restrict clinical application. Herein, the photobactericidal activity of novel polyurethane substrates containing cadmium-free quantum dots was tested against clinical multi-drug resistant Gram-positive and Gram-negative bacterial strains: methicillin-resistant Staphylococcus aureus (MRSA) and a carbapenemase-producing strain of Escherichia coli (E. coli). To enhance the capacity for reactive oxygen species generation, QDs were incorporated into the polymer with a photosensitising dye, crystal violet. Close proximity between the QD and dye enables electron and energy transfer processes leading to generation of cytotoxic singlet oxygen and superoxide radicals. A QD solution in cyclohexane was premixed with a solution of CV in the more polar solvent, dichloromethane, to promote the formation of QD-CV nanocomposite complexes via CV adsorption. This solution was then used to embed the quantum dots and crystal violet into medical grade polyurethane via swell-encapsulation. The combination of QD and CV elicited significant synergistic antibacterial activity under visible light against MRSA within 1 h (99.98% reduction) and E. coli within 4 h (99.96% reduction). Photoluminescence lifetime and singlet oxygen phosphorescence measurements demonstrated interaction between the quantum dots and the crystal violet occurs within the polymer that can lead to enhanced generation of reactive oxygen species. Strong inhibition of kill was observed using the superoxide scavenger, superoxide dismutase. The efficacy of these QD-CV polymer substrates that can harvest light across the visible spectrum, against multi-drug resistant bacteria demonstrates the feasibility of this approach.

Type: Article
Title: Photoactivable Polymers Embedded with Cadmium-free Quantum Dots and Crystal Violet: Efficient Bactericidal Activity against Clinical Strains of Antibiotic-Resistant Bacteria
Open access status: An open access version is available from UCL Discovery
DOI: 10.1021/acsami.9b02109
Publisher version: https://doi.org/10.1021/acsami.9b02109
Language: English
Additional information: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
UCL classification: UCL
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences > Div of Surgery and Interventional Sci
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences > Div of Surgery and Interventional Sci > Department of Surgical Biotechnology
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences > Eastman Dental Institute
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences > Eastman Dental Institute > Microbial Diseases
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry
URI: https://discovery.ucl.ac.uk/id/eprint/10070358
Downloads since deposit
0Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item