Antimicrobial blue light: A 'Magic Bullet' for the 21st century and beyond?

Abstract

Over the past decade, antimicrobial blue light (aBL) at 400 - 470 nm wavelength has demonstrated immense promise as an alternative approach for the treatment of multidrug-resistant infections. Since our last review was published in 2017, there have been numerous studies that have investigated aBL in terms of its, efficacy, safety, mechanism, and propensity for resistance development. In addition, researchers have looked at combinatorial approaches that exploit aBL and other traditional and non-traditional therapeutics. To that end, this review aims to update the findings from numerous studies that capitalize on the antimicrobial effects of aBL, with a focus on: efficacy of aBL against different microbes, identifying endogenous chromophores and targets of aBL, Resistance development to aBL, Safety of aBL against host cells, and Synergism of aBL with other agents. We will also discuss our perspective on the future of aBL.

Keywords: Antimicrobial blue light; Antimicrobial resistance; Antimicrobial synergism; Infectious diseases; Microbes; Photolysis.

Conflict of interest statement

Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Copyright © 2021 Elsevier B.V. All rights reserved.

Figures

Figure 1.

Schematic of the proposed mechanism of aBL for the killing of pathogenic microbes

Figure 2.

Killing kinetics of different strains of N. gonorrhoeae. Error Bars: standard error of the mean. Taken from Wang et al. [Wang et al.]

Figure 3.

Bar graph showing the changes in relative fluorescence as following 10 J/cm2 or 20 J/cm2. In addition, a dark control was included. Figure taken from Fila et al., [69].

Figure 4.

Images showing the ‘photolysis’ effect on STX following different illumination times of aBL (460 nm; 20 min or 40 min). Figure taken from Dong et al., [93].

Figure 5.

a) Mice image showing treatment of MRSA within an abrasion would in a mouse model using the dual-wavelength (460 nm + 405 nm) approach. b) scatter plot showing the log10 CFU/cm2 (based on the size of wound) following the: control, 460 nm, 405 nm, or combined 460 nm + 405 nm. Statistical analyses were a paired t-test or ANOVA. Error bars: standard error of the mean. Images taken from Leanse et al. [80].