Instead of plain sterile cotton or other fibers, this dressing is made of “composite fibers with a core electrical heater covered by a layer of hydrogel containing thermoresponsive drug carriers,” which really says it all.
It acts as a regular bandage, protecting the injury from exposure and so on, but attached to it is a stamp-sized microcontroller. When prompted by an app (or an onboard timer, or conceivably sensors woven into the bandage), the microcontroller sends a voltage through certain of the fibers, warming them and activating the medications lying dormant in the hydrogel.
Those medications could be anything from topical anesthetics to antibiotics to more sophisticated things like growth hormones that accelerate healing. More voltage, more medication — and each fiber can carry a different one.