Multifunctional antimicrobial dressings were developed that feature fluorescent sensors that glow brightly under UV light if infection starts to set in and can be used to monitor the healing progress. The smart dressings harness the powerful antibacterial and antifungal properties of magnesium hydroxide.
They are cheaper to produce than silver-based dressings but equally as effective in fighting bacteria and fungi, with their antimicrobial power lasting up to a week. Currently, the only way to check the progress of wounds is by removing bandage dressings, which is both painful and risky and gives pathogens the chance to attack. Being able to easily see if something is going wrong would reduce the need for frequent dressing changes and help to keep wounds better protected.
Though magnesium is known to be antimicrobial, anti-inflammatory, and highly biocompatible, there has been little practical research on how it could be used on medically relevant surfaces like dressings and bandages. The team developed fluorescent magnesium hydroxide nanosheets that could contour to the curves of bandage fibers.
The research team synthesized the nanosheets, which are 10,000 to 100,000 times thinner than a human hair, and embedded them onto a batch of nanofibers. The magnesium hydroxide nanosheets respond to changes in pH, which makes them ideal for use as sensors to track healing.
Healthy skin is naturally slightly acidic while infected wounds are moderately alkaline. Under UV light, the nanosheets glow brightly in alkaline environments and fade in acidic conditions, indicating the different pH levels that mark the stages of wound healing. The nanosheets are easily integrated onto any biocompatible nanofiber, which means they can then be deposited onto standard cotton bandages.
Laboratory tests showed the magnesium hydroxide nanosheets were nontoxic to human cells while destroying emerging pathogens like drug-resistant golden staph and Candida auris. The process to make the fluorescent nanosheets was simple to scale for potential mass production.