Lethal photosensitisation of Staphylococcus aureus and Escherichia coli using crystal violet and zinc oxide-encapsulated polyurethane

Abstract

Crystal violet and zinc oxide nanoparticles (CVZnO) were incorporated into medical grade polyurethane polymers by a two-step dipping procedure to prepare novel bactericidal surfaces. The photobactericidal activity of CVZnO polyurethane samples was tested against the Gram-positive bacterium, Staphylococcus aureus and the Gram-negative bacterium, Escherichia coli. Exposure of the polymer samples to white light induced the lethal photosensitisation of both S. aureus and E. coli. In addition, this novel system demonstrated significant antibacterial activity under dark conditions against S. aureus within 2 hours, but more remarkably, a 99.9% reduction in the numbers of E. coli within 4 hours in the dark. This is, to the best of our knowledge, the most potent 'dark-kill' by a light activated antimicrobial agent ever reported.The singlet oxygen quenchers, bovine serum albumin and L-histidine, and an enzyme which catalyses the decomposition of hydrogen peroxide, bovine catalase, were incorporated into the antibacterial assays to determine if the mechanism of E. coli kill involved a Type 1 or a Type 2 light-activated process.

Enhancing the Antibacterial Activity of Light-Activated Surfaces Containing Crystal Violet and ZnO Nanoparticles: Investigation of Nanoparticle Size, Capping Ligand, and Dopants

“…21 We have previously reported a detailed description of the photochemical mechanisms involved in PDT. 20 …”

Superior performance of macroporous over gel type polystyrene as a support for the development of photo-bactericidal materials

“…[24][25][26][27][28][29][30][31][32][33][34][35] Regarding the supports for the photoactive agents, a variety of materials have been described in the literature, like polyurethane, cellulose, nylon, chitosan, silica and polystyrene. [13][14][15][16][17][18][19][20] This last polymer is one of the most popular supports employed so far, dating back to the pioneering works of Schaap and Neckers. 36 Polystyrene is a versatile system, used in applications as diverse as fluorescence sensing 37 or catalysis.…”

“…aPDI can be applied using soluble 12 or supported photosensitizers. [13][14][15][16][17][18][19][20] A broad number of chemical families have been proposed as effective generators of ROS, especially singlet oxygen ( 1 O 2 ). 21 Among those molecules, xanthenic dyes, phenothiazinium compounds, porphyrins and phthalocyanins have been studied.…”

Potent Antibacterial Activity of Copper Embedded into Silicone and Polyurethane

“…9,10,[12][13][14][15][16][17]29,30 In this paper we have achieved highly significant antibacterial activity without the need for light and without effecting a change in the appearance of the materials. For aesthetic reasons, a material that is not brightly coloured, yet rapidly kills bacteria is more appealing for frequently touched surfaces in and around hospital wards.…”

“…7 Our research group has developed new ways to potentially reduce HAIs associated with medical devices, by developing new polymeric materials that can be used as catheter materials and to coat hospital surfaces. [8][9][10][11][12][13][14][15][16][17] Such materials include silicone rubber, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 polyvinylchloride, polyurethane and polypropylene. 18 These materials can also be used to treat HAIs caused by commonly touched surfaces in hospital wards (e.g.…”