Development of 405 nm HINS-light technology for decontamination applications in arthroplasty surgery

P. Ramakrishnan, M. MacLean, S. J. MacGregor, J. G. Anderson, M. H. Grant

Research output: Contribution to journalMeeting abstract

Abstract

Healthcare associated infections (HAI) pose a major threat to patients admitted to hospitals, and infection rates following orthopaedic arthroplasty surgery are as high as 4%, while the infection rates are even higher after revision surgery. 405 nm High-Intensity Narrow Spectrum (HINS) light has been proven to reduce environmental contamination in hospital isolation rooms, and there is potential to develop this technology for application in orthopaedic surgery.

Cultured rat osteoblasts were exposed to 405 nm light to investigate if bactericidal doses of light could be used safely in the presence of mammalian cells. Cell viability was measured by MTT reduction and microscopy techniques, function by alkaline phosphatase activity, and proliferation by the BrdU assay. Exposures of up to a dose of 36 J/cm2 had no significant effect on osteoblast cell viability, whilst exposure of a variety of clinically relevant bacteria, to 36 J/cm2 resulted in up to 100% kill. Exposure to a higher dose of 54 J/cm2 significantly affected the osteoblast cell viability, indicating dose dependency.

Work also demonstrated that 405 nm light exposure induces reactive oxygen species (ROS) production in both mammalian and bacterial cells, as shown by fluorescence generated from 6-carboxy-2′,7′-dichlorodihydrofluorescein diacetate dye. The mammalian cells were significantly protected from dying at 54 J/cm2 by catalase, which detoxifies H2O2. Bacterial cells were significantly protected by sodium pyruvate (H2O2 scavenger) and by a combination of free radical scavengers (sodium pyruvate, dimethyl thiourea (·OH scavenger), catalase) at 162 and 324 J/cm2. Thus the cytotoxic mechanism of 405 nm light in mammalian cells and bacteria is likely oxidative stress involving predominantly H2O2 generation, with other ROS contributing to the damage.

Additional work describing the potential for incorporation of this antimicrobial light within operating theatre lighting systems will also be discussed, and this, coupled with the cell viability and cytotoxicity results, suggests that 405 nm light could have great potential for continual patient safe decontamination during orthopaedic replacement surgeries and thereby reduce the incidence of infections.

Fingerprint

Decontamination
Arthroplasty
Technology
Light
Cell Survival
Osteoblasts
Orthopedics
Cross Infection
Pyruvic Acid
Catalase
Reactive Oxygen Species
Isolation Hospitals
Sodium
Bacteria
Thiourea
Free Radical Scavengers
Bromodeoxyuridine
Infection
Lighting
Reoperation

Keywords

  • 405 nm light
  • high-intensity narrow spectrum light
  • HINS-light
  • healthcare associated infections
  • environmental contamination
  • bactericide
  • bacterial cells

Cite this

@article{83765047f3cd4f898a88f60374e21b16,
title = "Development of 405 nm HINS-light technology for decontamination applications in arthroplasty surgery",
abstract = "Healthcare associated infections (HAI) pose a major threat to patients admitted to hospitals, and infection rates following orthopaedic arthroplasty surgery are as high as 4{\%}, while the infection rates are even higher after revision surgery. 405 nm High-Intensity Narrow Spectrum (HINS) light has been proven to reduce environmental contamination in hospital isolation rooms, and there is potential to develop this technology for application in orthopaedic surgery.Cultured rat osteoblasts were exposed to 405 nm light to investigate if bactericidal doses of light could be used safely in the presence of mammalian cells. Cell viability was measured by MTT reduction and microscopy techniques, function by alkaline phosphatase activity, and proliferation by the BrdU assay. Exposures of up to a dose of 36 J/cm2 had no significant effect on osteoblast cell viability, whilst exposure of a variety of clinically relevant bacteria, to 36 J/cm2 resulted in up to 100{\%} kill. Exposure to a higher dose of 54 J/cm2 significantly affected the osteoblast cell viability, indicating dose dependency.Work also demonstrated that 405 nm light exposure induces reactive oxygen species (ROS) production in both mammalian and bacterial cells, as shown by fluorescence generated from 6-carboxy-2′,7′-dichlorodihydrofluorescein diacetate dye. The mammalian cells were significantly protected from dying at 54 J/cm2 by catalase, which detoxifies H2O2. Bacterial cells were significantly protected by sodium pyruvate (H2O2 scavenger) and by a combination of free radical scavengers (sodium pyruvate, dimethyl thiourea (·OH scavenger), catalase) at 162 and 324 J/cm2. Thus the cytotoxic mechanism of 405 nm light in mammalian cells and bacteria is likely oxidative stress involving predominantly H2O2 generation, with other ROS contributing to the damage.Additional work describing the potential for incorporation of this antimicrobial light within operating theatre lighting systems will also be discussed, and this, coupled with the cell viability and cytotoxicity results, suggests that 405 nm light could have great potential for continual patient safe decontamination during orthopaedic replacement surgeries and thereby reduce the incidence of infections.",
keywords = "405 nm light, high-intensity narrow spectrum light, HINS-light, healthcare associated infections, environmental contamination, bactericide, bacterial cells",
author = "P. Ramakrishnan and M. MacLean and MacGregor, {S. J.} and Anderson, {J. G.} and Grant, {M. H.}",
year = "2016",
month = "10",
day = "27",
language = "English",
volume = "98-B",
pages = "22",
journal = "Bone & Joint Journal : Orthopaedic Proceedings Supplement",
issn = "1358-992X",
number = "SUPP 16",

}

Development of 405 nm HINS-light technology for decontamination applications in arthroplasty surgery. / Ramakrishnan, P.; MacLean, M.; MacGregor, S. J.; Anderson, J. G.; Grant, M. H.

In: Bone & Joint Journal : Orthopaedic Proceedings Supplement, Vol. 98-B, No. SUPP 16, 27.10.2016, p. 22.

Research output: Contribution to journalMeeting abstract

TY - JOUR

T1 - Development of 405 nm HINS-light technology for decontamination applications in arthroplasty surgery

AU - Ramakrishnan, P.

AU - MacLean, M.

AU - MacGregor, S. J.

AU - Anderson, J. G.

AU - Grant, M. H.

PY - 2016/10/27

Y1 - 2016/10/27

N2 - Healthcare associated infections (HAI) pose a major threat to patients admitted to hospitals, and infection rates following orthopaedic arthroplasty surgery are as high as 4%, while the infection rates are even higher after revision surgery. 405 nm High-Intensity Narrow Spectrum (HINS) light has been proven to reduce environmental contamination in hospital isolation rooms, and there is potential to develop this technology for application in orthopaedic surgery.Cultured rat osteoblasts were exposed to 405 nm light to investigate if bactericidal doses of light could be used safely in the presence of mammalian cells. Cell viability was measured by MTT reduction and microscopy techniques, function by alkaline phosphatase activity, and proliferation by the BrdU assay. Exposures of up to a dose of 36 J/cm2 had no significant effect on osteoblast cell viability, whilst exposure of a variety of clinically relevant bacteria, to 36 J/cm2 resulted in up to 100% kill. Exposure to a higher dose of 54 J/cm2 significantly affected the osteoblast cell viability, indicating dose dependency.Work also demonstrated that 405 nm light exposure induces reactive oxygen species (ROS) production in both mammalian and bacterial cells, as shown by fluorescence generated from 6-carboxy-2′,7′-dichlorodihydrofluorescein diacetate dye. The mammalian cells were significantly protected from dying at 54 J/cm2 by catalase, which detoxifies H2O2. Bacterial cells were significantly protected by sodium pyruvate (H2O2 scavenger) and by a combination of free radical scavengers (sodium pyruvate, dimethyl thiourea (·OH scavenger), catalase) at 162 and 324 J/cm2. Thus the cytotoxic mechanism of 405 nm light in mammalian cells and bacteria is likely oxidative stress involving predominantly H2O2 generation, with other ROS contributing to the damage.Additional work describing the potential for incorporation of this antimicrobial light within operating theatre lighting systems will also be discussed, and this, coupled with the cell viability and cytotoxicity results, suggests that 405 nm light could have great potential for continual patient safe decontamination during orthopaedic replacement surgeries and thereby reduce the incidence of infections.

AB - Healthcare associated infections (HAI) pose a major threat to patients admitted to hospitals, and infection rates following orthopaedic arthroplasty surgery are as high as 4%, while the infection rates are even higher after revision surgery. 405 nm High-Intensity Narrow Spectrum (HINS) light has been proven to reduce environmental contamination in hospital isolation rooms, and there is potential to develop this technology for application in orthopaedic surgery.Cultured rat osteoblasts were exposed to 405 nm light to investigate if bactericidal doses of light could be used safely in the presence of mammalian cells. Cell viability was measured by MTT reduction and microscopy techniques, function by alkaline phosphatase activity, and proliferation by the BrdU assay. Exposures of up to a dose of 36 J/cm2 had no significant effect on osteoblast cell viability, whilst exposure of a variety of clinically relevant bacteria, to 36 J/cm2 resulted in up to 100% kill. Exposure to a higher dose of 54 J/cm2 significantly affected the osteoblast cell viability, indicating dose dependency.Work also demonstrated that 405 nm light exposure induces reactive oxygen species (ROS) production in both mammalian and bacterial cells, as shown by fluorescence generated from 6-carboxy-2′,7′-dichlorodihydrofluorescein diacetate dye. The mammalian cells were significantly protected from dying at 54 J/cm2 by catalase, which detoxifies H2O2. Bacterial cells were significantly protected by sodium pyruvate (H2O2 scavenger) and by a combination of free radical scavengers (sodium pyruvate, dimethyl thiourea (·OH scavenger), catalase) at 162 and 324 J/cm2. Thus the cytotoxic mechanism of 405 nm light in mammalian cells and bacteria is likely oxidative stress involving predominantly H2O2 generation, with other ROS contributing to the damage.Additional work describing the potential for incorporation of this antimicrobial light within operating theatre lighting systems will also be discussed, and this, coupled with the cell viability and cytotoxicity results, suggests that 405 nm light could have great potential for continual patient safe decontamination during orthopaedic replacement surgeries and thereby reduce the incidence of infections.

KW - 405 nm light

KW - high-intensity narrow spectrum light

KW - HINS-light

KW - healthcare associated infections

KW - environmental contamination

KW - bactericide

KW - bacterial cells

UR - http://www.bjjprocs.boneandjoint.org.uk/cgi/content/abstract/98-B/SUPP_16/22.

UR - http://www.borsoc.org.uk/meetings.html

M3 - Meeting abstract

VL - 98-B

SP - 22

JO - Bone & Joint Journal : Orthopaedic Proceedings Supplement

T2 - Bone & Joint Journal : Orthopaedic Proceedings Supplement

JF - Bone & Joint Journal : Orthopaedic Proceedings Supplement

SN - 1358-992X

IS - SUPP 16

ER -