Image: A stained epidermis cells cultured on the A5G81 peptide (Photo courtesy of Guillermo Ameer /Northwestern University).
A shape-conforming hydrogel regenerative bandage leverages the body's own healing mechanisms to heal painful, hard-to-treat diabetic foot ulcers (DFUs), claims a new study.
Developed by researchers at Northwestern University (NU; Chicago, IL, USA), the biodegradable, antioxidant, shape-conforming regenerative dressing is based on A5G81, a laminin-derived peptide (12 amino acids in length) that that is critical for the wound-healing process. A5G81 is grafted onto a thermoresponsive citrate-based macromolecular scaffold to facilitate adhesion and propagation of skin cells throughout the hydrogel, while at the same time significantly increasing cell proliferation and migration.
The hydrogel is thermally responsive; while in a liquid state when applied to the wound bed, it rapidly solidifies into a viscous state when exposed to body temperature. The phase change allows the hydrogel to conform to the exact shape of the wound. In addition, the bandage's antioxidant nature counters inflammation. According to the researchers, the peptide-hydrogel system represents a paradigm shift in clinical strategies for treating DFU, without the need for soluble biologic or pharmacologic factors. The study was published on June 11, 2018, in Proceedings of the National Academy of Sciences (PNAS).
“The novelty is that we identified a segment of a protein in skin that is important to wound healing, made the segment, and incorporated it into an antioxidant molecule that self-aggregates at body temperature to create a scaffold that facilitates the body's ability to regenerate tissue at the wound site,” said senior author Professor Guillermo Ameer, MD, PhD. “Wounds have irregular shapes and depths. Our liquid can fill any shape and then stay in place. Other bandages are mostly based on collagen films or sponges that can move around and shift away from the wound site.”
Laminins are high-molecular weight proteins of the extracellular matrix (ECM) that are an important and biologically active part of the basal lamina, influencing cell differentiation, migration, and adhesion. They are an integral part of structural scaffolding in almost every tissue. Fifteen laminin trimers have so far been identified, each composed of different combinations of alpha-, beta-, and gamma-chains.