Small electric generators help with wound healing.

 Tiny dressings that generate electricity in response to movement have the potential to speed up wound healing and tissue regeneration. In the journal Science and Technology of Advanced Materials, Taiwanese scientists reviewed the most recent advances and potential applications of wound healing technology.

Natural wound healing involves complex interactions between ions, cells, blood vessels, genes, and the immune system, with each player being triggered by a series of molecular events. The damaged epithelium - the layer of cells that covers tissue - generates a weak electric field as part of this process. The electric field is created by an ion gradient in the wound bed, and it is important in directing cell migration and promoting blood vessel formation in the area.

In the mid- to late-1900s, scientists discovered that stimulating tissue with an electric field could improve wound healing. Current research in this field is focusing on developing small, wearable, and low-cost patches that are not hampered by external electrical equipment.

This has resulted in research on piezoelectric materials, which include natural materials such as crystals, silk, wood, bone, hair, and rubber, as well as synthetic materials such as quartz, ceramics, and polymers. When mechanical stress is applied to these materials, an electric current is generated. Nanogenerators made of synthetic materials appear to be particularly promising.

Some research groups, for example, are investigating the use of self-powered piezoelectric nanogenerators made of zinc oxide nanorods on a polydimethylsiloxane matrix for accelerating wound healing. The fact that zinc oxide is piezoelectric and biocompatible is an advantage. Other researchers are using polyurethane and polyvinylidene fluoride (PVDF) scaffolds because of their high piezoelectricity, chemical stability, ease of manufacturing, and biocompatibility. In laboratory and animal studies, these and other piezoelectric nanogenerators have shown promising results.

A triboelectric nanogenerator (TENG) generates an electric current when two interfacing materials come into and out of contact with each other. TENGs, which generate electricity from breathing movements, have been used in experiments to speed up wound healing in rats. They've also loaded antibiotics into TENG patches to help with wound healing while also treating localized infection.

"Because of their light weight, flexibility, elasticity, and biocompatibility, piezoelectric and triboelectric nanogenerators are excellent candidates for self-assisted wound healing," says bioengineer Zong-Hong Lin of Taiwan's National Tsing Hua University. "However, there are several bottlenecks in their clinical application."

They still need to be customized, for example, because wound dimensions vary greatly. They must also be securely attached without being harmed or corroded by the fluids that naturally exude from wounds.

"Our long-term goal is to develop cost-effective and highly efficient wound dressing systems for clinical applications," Lin says.