A new, scalable approach to speeding up wound healing has been developed based on heat-responsive hydrogels; that are mechanically active, stretchy, tough, highly adhesive and antimicrobial active adhesive dressings (AADs). As skin injuries are painful and can compromise the integrity and protective function of the skin; resulting in infections.
Most treatments for skin wounds involve simply placing a barrier; over it to keep it moist, limit pain, and reduce exposure to infectious microbes; but do not actively assist in the healing process. More sophisticated wound dressings; that can monitor aspects of healing such as pH and temperature and deliver therapies to a wound site have been developed in recent years.
This technology has the potential to be used not only for skin injuries; but also for chronic wounds like diabetic ulcers and pressure sores, for drug delivery, and as components of soft robotics-based therapies. AADs take their inspiration from developing embryos; whose skin is able to heal itself completely, without forming scar tissue.
Adhesive wound closure
To achieve this, the embryonic skin cells around a wound produce fibers made of the protein actin that contract to draw the wound edges together, like a drawstring bag being pulled closed. Skin cells lose this ability once a fetus develops past a certain age, and any injuries that occur after that point cause inflammation and scarring during the healing process
In order to mimic the contractile forces that pull embryonic skin wounds closed; the researchers extended the design of previously developed tough adhesive hydrogels by adding a thermoresponsive polymer known as PNIPAm, which both repels water and shrinks at around 90° F. The resulting hybrid hydrogel begins to contract when exposed to body temperature.
This transmits the force of the contracting PNIPAm; component to the underlying tissue via strong bonds between the alginate hydrogel and the tissue. In addition, silver nanoparticles are embedding in the AAD to provide antimicrobial protection. The AAD bonded to pig skin with over ten times the adhesive force of a Band-Aid and prevented bacteria from growing.
so this technology is already significantly better; than most commonly using wound protection products; even before considering its wound-closing properties. to pursue additional preclinical studies to demonstrate AAD’s potential as a medical product; and then work toward commercialization. TAs have achieved adhesion energies up to 1000 J m−2on various tissues, including skin, even with exposure to blood and dynamic tissue movements.