Undergraduate Research at Virginia Tech

Beyond Adhesive Bandages: Synthesizing Medical Adhesives

By Emily Olsen, marketing management

For small cuts and bumps, adhesive bandages are a great first aid tool, but for major wounds and amputated extremities, bandages just don't cut it. That's why the United States Army in collaboration with Nanosonic Inc. of Blacksburg, Va., requested that Virginia Tech's chemistry department research and develop a product that was capable of dressing large wounds.

After being bored with a biology internship that kept him out in the wilderness all summer, Dan Crowther, a senior biology major, decided he would give a chemistry internship a try. He applied and received a 12-week internship through the chemistry department. He was placed with Afia Karikari, a graduate student in chemistry at Virginia Tech, who is working under the direction of Professor Tim Long to create the bio-adhesive the Army was looking for.

Since the purpose of the research was to create a bio-adhesive to be used on the body, they decided to work with lactic acid, which comes from and is broken down naturally by the human body. Crowther's job for the first week was to take single lactide molecules (monomers) and turn them into chains, or polymers. These polymers would be the main component of the adhesive.

In particular, Crowther worked with star-shaped polymers, the preferred polymer for biomedical applications, such as sutures, but which has not been much studied for adhesives. Researchers are now starting to see that star-shaped molecules may be the best option for the adhesive. The star shape, in comparison to a linear shape, has more points that are able to react together to generate a mechanically robust adhesive. These star shaped polymers help to create an adhesive that is more durable and more viscous.

To create the adhesive, Crowther had to functionalize each polymer star, which meant adding a photo-reactive group to the end of each chain to make it a light-curable precursor. From that point all Crowther had to do was shine light on the liquid substance in order to transform it into an adhesive. The final product was a sticky polymers that can be transformed with light into a durable, stretchy film. Currently, the process takes a large quantity of light, which means it's not quite ready for any real world applications; however, researchers hope to improve upon the substance so that it can form an adhesive merely from the light of the sun.

Towards the end of the summer, Crowther took the substance that had been created and tested it to see how long it would take to disintegrate in the human body. He set up a phosphate buffer solution that was near body conditions and measured how long it would take for the adhesive to dissolve. Although Crowther didn't get to spend too much time on this part of the research, it was continued by another student after he left. The results will be a crucial aspect of the overall success of the adhesive.

According to Crowther, there is still plenty of research to be done before the adhesive will be used by the public but it could be completed in the near future.

In the end, he found the experience to be valuable but learned that he didn't want a job that kept him tied to the lab everyday. Crowther would advise students pursuing any type of research or graduate school to get their feet wet with an undergraduate research program. He believes it can really help you find where you want to be in your career.