Blue Light Therapy for Drug-Resistant Bacterial Infections in Burn Wounds in a Mouse Model

Begin with an anesthetized mouse with its back exposed, placed on a Petri dish lid.

The mouse has a burn wound infected with bioluminescent, drug-resistant bacteria.

Cover the mouse’s eyes with aluminum foil to avoid overexposure to blue light.

Place the mouse under a blue LED device at a fixed distance.

Irradiate the wound at a constant intensity. Increase the exposure time to deliver higher doses.

The light penetrates the wound tissue and reaches the colonizing bacteria.

Within these bacteria, light-sensitive molecules absorb the blue light and become photoactivated, producing reactive oxygen species (ROS).

ROS damage bacterial components, including bioluminescent proteins, leading to bacterial cell death with minimal harm to the surrounding tissue.

After each exposure, perform bioluminescence imaging to monitor bacterial viability around the wound.

As the dose increases, the signal declines correspondingly.

This decline indicates the antibacterial effect of blue light-induced oxidative stress.

After anesthetizing the mice, according to the text protocol, randomly divide the animals into an antimicrobial blue light or aBL-treated group and an untreated control group. For the aBL-treated group, use aluminum foil to cover the eyes of the mice to avoid overexposure to light. Place the mouse burns directly under the LED with a lid of a 35 millimeter petri dish underneath the mouse abdomen to keep the back in a horizontal position.

Next, replace the power energy meter with a mouse on a square petri dish. Then adjust the height of the mouse back to a position where the distance between the LED aperture and the surface of the mouse burn is equal to the distance between the LED aperture and the light sensor of the power energy meter. Irradiate the infected burns at an irradiance of 100 milliwatts per centimeter squared.

Deliver aBL in aliquots of 72 joules per centimeter squared until the total dose of 360 joules per centimeter squared is reached. After each light dose, perform bioluminescence imaging of the mouse burns, as demonstrated earlier in this video. For the untreated control group, perform bioluminescence imaging of the mouse burns using the same time intervals as used for the aBL-treated group.