the clotting power of KOD
Hartgerink Lab/Rice University
Researchers have synthesized a collagen mimetic that may help wounds heal by directing the natural clotting of blood.
It was several years ago that the team developed KOD, a synthetic collagen mimetic made of 36 amino acids that self-assemble into triple-helix nanofibers and hydrogels.
With their latest research, the group showed that KOD collagen matrices adhere to platelets and activate them, thereby creating clots in blood and plasma.
An account of this research appears in Biomacromolecules.
“We showed we can make small peptides that we can easily synthesize chemically . . .,” said study author Jeffrey Hartgerink, PhD, of Rice University in Houston, Texas.
“Those peptides self-assemble into fibers that, in turn, become a hydrogel. This hierarchy of assembly—from a peptide to a triple helix to a fiber to a hydrogel—mimics much of the hierarchy of assembly of natural collagen.”
Dr Hartgerink added that collagen’s importance goes beyond its role as a scaffold for cells.
“We’ve been thinking about KOD for hemostasis for a long time,” he said. “Natural collagen is already used in a variety of on-the-market products for hemostasis, but there are benefits to a synthetic system. We can avoid the immune problems associated with using collagen from cows, for example. The ability to synthesize KOD chemically gives us a pure product.”
Lab tests showed that KOD hydrogel traps red blood cells to stop bleeding and, unlike commercial barriers, binds and activates platelets that form clots to promote healing. The synthetic collagen matrices adhered to the platelets, and their activation was confirmed via the secretion of soluble P-selectin.
The tests also indicated that KOD does not promote inflammation. The researchers incubated THP-1 monocytes with KOD and observed “minimal” production of the proinflammatory cytokines TNF-α and IL-1β.
The team therefore believes KOD could improve upon commercial sponges or therapies based on naturally derived porcine or bovine-derived collagen that are now used to aid healing during or after surgery.
“We wouldn’t envision using KOD for major trauma, because there are conventional methods like tourniquets or using clay-based materials that are much more effective in that immediate situation,” said study author Vivek Kumar, PhD, also of Rice University.
“This is not going to be a battlefield dressing or something a first-responder is likely to use,” Dr Hartgerink added. “But when the goal is to promote delicate and natural healing where scarring is a concern, this can be more nuanced and effective.”
