Looking Global
B
BARNACLES Nature's little helpers for heavily hurt humans
arnacles are easily one of the strangest creatures ever to exist. They are those sticky little fellows found exclusively by the seaside that seem to cling to anything and everything with a force matched only by Thor’s Mjölnir. These weird inhabitants are sessile (they are not mobile) and are suspension feeders (or filter feeders). They cling and make themselves at home on boat hulls, tidal rocks and even whales.
reactive oxygen at the seawater interface. As the secretion advances, nearby biofilms rapidly oxidise and lift off the surface, essentially cleaning it. Basically, the oily fluid sweeps away any kind of contaminants and then primes the surface for the glue, similar to priming a wall before it is painted. After this, the barnacle secretes its fancy bio-cement which would most probably not have been able to stick onto the surface without the previous cleaning step.
Not much is discussed about them as they seem very insignificant, or annoying even (as you just CANNOT get them off). What is, however, phenomenal about these small arthropods is the sheer strength by which they fasten themselves to their object of choice. They almost become part of the object they are so desperately attached to.
This mechanism is what the researchers are attempting to mimic. They grinded up some adhesive sheets and mixed them with a silicone oil that repels blood, thus forcing the blood away from the wound. Initial trials have proven to be exceptional, and for smaller wounds (at this stage only small wounds are being tested) the results are demonstrating outcomes where wounds are being sealed with no further blood loss within 10 seconds while also withstanding eight times the breaking pressure compared to current alternatives.
Barnacle larvae swim along in the sea until they reach an age where they need to “stick” to something. The sticking mechanism is as basic as a kindergarten example, as what they essentially do is to simply secrete a glue-like substance and then attach themselves. The glue is incredibly strong, as most of us know, and even after the barnacle has died, it will just keep on sticking. It has been the subject of many studies as such an incredibly strong adhesive has enormous potential, especially considering the fact that this “glue” works in a strongly alkaline liquid (i.e., the ocean). It works on smooth metallic surfaces such as hulls of boats and ships, but it also works on the soft, flexible skin of a whale. Not a single manmade product can achieve what the glue of a barnacle can. It was on this wave of thought that researchers at MIT (Massachusetts Institute of Technology) began thinking of a new way to seal a human wound as fast as possible. Millions of people world-wide die from blood loss every year. Blood loss can occur from trauma, an accident or on the operating table. Human blood has the ability to clot by itself, which it does for a small wound but when blood is gushing out of a large slash at an alarming rate, it is impossible. Modern medicine has designed certain wound adhesives, but they have proved ineffective against major injuries. These adhesives rely on coagulants (which take time) as well as dry skin. Very often, the patient does not have either of those two. The researchers had a look at the way in which this glue is secreted and how it actually sticks to surfaces which are usually under water. The chemistry behind it is interesting indeed but a basic summary of events will also suffice. Barnacles start out their glue-on process by first secreting a phase-separating oily fluid. This fluid presents a phase that is rich in lipids and
Dr Hanjay Wang, a resident in Stanford University’s Cardiothoracic Surgery Department who played no part in this study, used the word “incredible” to describe the material. Naturally, as with all revolutionary ideas, there are still some details that will need to be ironed out, such as: • How long will the glue last? • As a foreign substance, will the human body not attempt to get rid of it? • Will there be toxicity problems? These are all questions that only further studies and trials can conclude. The potential of this glue also spans out to additional problems, such as patients who have blood disorders or are in need of blood thinners. Patients with haemophilia (a blood disease where your blood does not clot) will likely be excited about this concept. Dr Hyunwoo Yuk, a mechanical engineering scientist at MIT and one of the head pioneers on this project, believes strongly in always looking to the animal kingdom when faced with a medical problem. Animals’ fundamental tasks are to survive and reproduce. Although humans seem to have comprehended the latter, the former is still a struggle for us to understand fully. He believes that whatever one attempts to heal, or fix, there is without a doubt already an organism out there doing exactly that. Daniela Steenkamp
39
