Brainy bandages

Infection-revealing biosensors may someday make wound care a consultation between doctor and bandage. Researchers have placed a sensing device in a wound-friendly gel and shown that the device’s color-based signaling still works.

The biosensors, made of silicon infiltrated with nanoscale pores, are optical devices that can be constructed to reflect only a certain color when white light hits them. For wound care, the researchers suggest, the biosensor pores would contain molecules, such as antibodies, that bind to microbe-specific proteins. When present in a wound, those proteins would get stuck in the pores and change the color of the light that the device reflects.

One drawback to current silicon biosensors is that they are made on a backing that’s too rigid to curve around wounds. So, Lisa A. DeLouise, a biomaterials scientist at the University of Rochester (N.Y.) Medical Center, and her colleagues decided to place the sensor portion within a hydrogel, which is more flexible.

Hydrogels already have a role in wound care, says DeLouise. Besides being soft and flexible, they keep the wound moist and absorb excess fluids.

In laboratory tests of the prototype smart bandages, which the researchers describe in the Sept. 16 Advanced Materials, DeLouise’s team found that the hydrogel-suspended sensors retained their color-changing capability. The researchers now plan to determine which protein-grabbing molecules to place in the pores for the best infection detection.