Colorado State University has invested in the future of biomedical engineering. Dr. Matt Kipper was, and is, one of these investments. Matt joined CSU, in 2006, as an assistant professor and researcher. He loves working with students in his lab and seeing what new ideas will appear. Matt told me a little about the shared interest among faculty in his field, “We have a core of researchers all interested in biomaterials.” Biomaterials research can be defined as researchers developing materials with biological functions, and then finding ways to make that function more useful to humanity. Some examples of biomaterials are bandages which prevent scar tissue, better joint replacements, and more. It’s a pretty popular field that is about 50 years old.
Matt focuses on the field of medicine, “I work primarily on a class of materials for biomedical applications. I work primarily with polysaccharides.” He looks at polysaccharides from the molecular scale to the visible realm. Matt develops materials from polysaccharides using the strategy of biomimetics. Biomimetics is the researcher’s way of mimicking nature in a targeted fashion. He also studies polysaccharide structure in order to learn about biological functions inherent in the material. Matt is very curious about the subject, “I believe there are many undiscovered functions, particularly with polysaccharides.”
There are other biopolymers which are easier to study, including proteins and nucleic acids. Matt told me, “We know a lot about their structure and function, in general, because if you have two copies of a protein, like actin, their function is governed by a very specific sequence and size.” Nucleic acids are similar. Polysaccharides are more varied in both sequence and size thus making it more difficult to pin them down for study.
Heparin is a specific polysaccharide that Matt is studying because, “It has a lot of sequence diversity.” If Matt collects heparin from a tissue sample, every heparin molecule will be different. The heparin molecules will have different sulfation patterns, size of the heparin will vary, and sequence variability is common. Deoxyribonucleic acid (DNA) and proteins have very specific binding partners which contribute to their structure. Good examples of the specific binding partners in DNA are the nucleotide bases which create the DNA double helix. Polysaccharides are more “promiscuous” according to Matt. The receptors can accept more binding partners than nucleic acids, and heparin’s structures reflect this lack of uniformity. Additionally, polysaccharides are less researched than DNA due to the limitations of current tools. Tools used for researching proteins and nucleic acids are simply more advanced than those used for polysaccharides.
The ease of sequencing and growing protein and DNA chains also enables scientists to have a more specific structure to study. Polysaccharides are multivalent in each individual sequence, which allows them to bind a partner in more than one spot. The change in reactivity is similar to holding hands with someone. You will enter a doorway differently depending on whether that person is on your right or left side, faster than you, or unwilling to enter the door. Polysaccharides change the way they react and grow based on how and where they their partners bind. Usually this is a carbon atom’s fault. Carbon can bond with four different atoms. All of these options affect the structure of a polysaccharide. That makes it hard to control how these molecules are formed in reactions. To make a long sequence, and specify exactly what chirality and binding partners a polysaccharide will have, can be done enzymatically. These enzymatic reactions are still stochastic, or random. However, a whole host of biological functions arise from this randomness. Matt can use all of these functions by simply transferring the polysaccharide to a separate material. This flexibility allows laboratories to mimic nature very easily to produce useful materials, yet it also makes it difficult to study how nature does its work. Matt calls it a blessing and a curse. Thankfully you and I can receive the benefits of this research in our lives as advances continue to be made from Matt and his peers’ hard work.