Synthesis, characterization and biological evaluation of a new photoactive hydrogel against Gram-positive and Gram-negative bacteria

Spagnul, Cinzia; Greenman, John; Wainwright, Mark; Kamil, Zeeniya; Boyle, Ross W.

Abstract

© 2016 The Royal Society of Chemistry. In 2013, the World Health Organization reported that 884 million people lack access to clean potable water. Photodynamic antimicrobial chemotherapy (PACT) is a very promising alternative to conventional antibiotics for the efficient inactivation of pathogenic microorganisms. We report the synthesis, characterization and antibacterial activity of a polyacrylamide-based hydrogel (7), with a new photoactive phenothiazinium compound (6) immobilized on it, to be used as a novel water-sterilizing device. The hydrogel was characterized by IR and scanning electron microscopy and incorporation of the dye confirmed by UV-visible spectroscopy. Antibacterial tests using the recombinant bioluminescent Gram-positive Staphylococcus aureus RN4220 and Gram-negative Escherichia coli DH5α were performed to assess the ability of the hydrogel to inactivate bacterial strains in solution. The hydrogel is characterized by a non-ordered microporous structure and is able to generate reactive oxygen species. The hydrogel is able to inactivate planktonic cells of the S. Aureus and E. Coli (3.3log and 2.3log killing, respectively) after 25 min of irradiation with white light at 14.5 mW cm -2 . The contact surface does not influence the kill rates while the killing rate increased by increasing the total amount of the hydrogel (0.27log drop to 1.65log drop with 0.5 mg cm -3 to 2.5 mg cm -3 of total amount of dye). The hydrogel was found to be active for four cycles, suggesting the possibility of reuse and it was shown to be active against both Gram-positive and Gram-negative species with no leaching of the active molecule.

Citation

Spagnul, C., Greenman, J., Wainwright, M., Kamil, Z., & Boyle, R. W. (2016). Synthesis, characterization and biological evaluation of a new photoactive hydrogel against Gram-positive and Gram-negative bacteria. Journal of Materials Chemistry B, 4(8), 1499-1509. https://doi.org/10.1039/c5tb02569a

• Journal Article Type: Article
• Acceptance Date: Jan 28, 2016
• Online Publication Date: Jan 28, 2016
• Publication Date: Jan 28, 2016
• Deposit Date: Feb 5, 2016
• Publicly Available Date: Jul 11, 2018
• Journal: Journals of material chemistry b
• Print ISSN: 2050-750X
• Electronic ISSN: 2050-7518
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 4
• Issue: 8
• Pages: 1499-1509
• DOI: https://doi.org/10.1039/c5tb02569a
• Keywords: Photodynamic; Antimicrobial; Chemotherapy
• Public URL: https://hull-repository.worktribe.com/output/384952
• Publisher URL: http://pubs.rsc.org/en/content/articlelanding/2016/tb/c5tb02569a#!divAbstract
• Additional Information: : This document is Similarity Check deposited; : Supplementary Information; : The Royal Society of Chemistry has an exclusive publication licence for this journal; OPEN ACCESS: This article is freely available. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (CC BY 3.0); : Single-blind; : Received 7 December 2015; Accepted 28 January 2016; Accepted Manuscript published 28 January 2016; Advance Article published 5 February 2016; Version of Record published 17 February 2016