Wednesday, 17 May 2017

Mussel Glue Mixture May Significantly Reduce Scarring

A group of researchers in South Korea has just made what could be an important discovery with respect to wound healing. They've used a mixture containing a protein from mussel glue to greatly reduce scarring in rats who experienced a serious skin injury. It's possible that the mixture may be helpful for reducing scarring in humans as well.


Mussels
Photo by stux, CC0 public domain license


Animal Testing


The experiment that was performed involved creating surface wounds in rats and then observing whether the test mixture reduced scar formation. As with many experiments with lab animals, the treatment of the animals could definitely be criticized. Using stem cells to create different types of human tissue and sections of organs may well reduce the use of animals in medical research in the future. It probably won't persuade researchers to abandon animal research altogether, though, because they sometimes want to look at whole-body effects.

Three classes of medical research are in vivo experiments (done in living things), in vitro experiments (done in lab equipment, and in silico experiments (done with computers or via computer simulations). I'm hoping that the last two types of experiments rapidly become more and more useful.



Collagen in Skin


Collagen is a fibrous protein that could be thought of as the scaffolding for our skin. It forms a network or mesh that helps to support the skin's structure and provide firmness. When we receive a significant wound, the skin that fills in the wound contains parallel strands of collagen in bundles instead of a fibrous network. This is a major contributor to the abnormal appearance of a scar.



Decorin


Decorin is a protein involved in the normal organization of collagen in the skin. It has been shown to reduce scarring when applied to wounds, but it isn't used therapeutically. It's a complex molecule that is too hard to make and too expensive to use. The Korean researchers used part of the decorin molecule in their experimental mixture, however. They also added a sticky substance from mussels and a collagen-binding molecule to the mixture. The mixture was then applied to the skin of rats with a major wound.



The Rat Experiment


The researchers say that the wounds in some of the animals were treated with the test mixture and then covered with plastic to keep the wound moist. In the other rats in the experiment (which formed the control group), the wound was covered with plastic but nothing else. The wounds on all of the rats had the same width and depth.


The New Scientist article referenced below shows pictures of the rats' wounds over time. Based on these photos, and assuming that there was no further change in skin appearance after day 28, it seems inaccurate to say that the experimental mixture prevented scarring as some headlines do (including the one in the referenced article). The mixture did reduce the size of the scar very significantly, however.

  • By Day 11, 99% of the wounds were closed in the test rats and 78% in the control group.
  • By Day 28, "treated rats had fully recovered" and there was very little scarring. The rats in the control group had thick purple scars.
The scientists found that the collagen in the healed wounds looked normal and that the skin contained oil glands, hair follicles, and blood vessels, structures that are absent from scars. 


Possible Application to Humans


Rats and humans are both mammals, so what applies to one often applies to the other. This isn't always the case, though. The researchers say that one factor which may be significant with respect to the scar experiment is that rats have looser skin than humans and tend to scar less. The scientists plan to experiment on pig skin next, which is more similar to human skin.



Research Reference


Mussel Gloop Can Be Used to Make Wounds Knit from New Scientist