Lab profile: Michelle L. Oyen, East Carolina University

Engineering can learn a great deal from nature, the master builder of structural materials with inherently small carbon footprints. Simultaneously, engineering is very helpful in expanding our understanding of biological systems. Michelle L. Oyen has devoted her career to this overlap between engineering and biology, and it has taken her research in many diverse directions from tissue engineering and regenerative medicine to modeling blood flow in the human placenta during pregnancy to structural materials inspired by bone and eggshell.

After receiving a B.S. in Materials Science and Engineering and an M. S. in Engineering Mechanics from Michigan State University, Oyen moved to the University of Minnesota for a Ph. D. in Biophysical Sciences and Medical Physics. She then moved to the University of Cambridge first as a Lecturer and subsequently as a Reader in Bioengineering and Fellow of Homerton College, before relocating to East Carolina University in 2018.

As well as her academic and research interests, Oyen is a committed science communicator, with numerous talks and appearances to her name, and is Editor-in-Chief of Materials Science and Engineering C: Materials for Biological Applications.

Michelle L. Oyen talked to Materials Today about her current research and future plans.

How long has your group been running?

I started my group in October 2006 in the Department of Engineering at the University of Cambridge in the UK. I was there running my lab for 11-and-a-half years through early 2018, when I relocated to East Carolina University (ECU) in August 2018. We’ve only been in our current location for six months although we have been in existence as a research entity for more than 12 years. 

How many staff makes up your group?

In the six months I’ve been at ECU to date I’ve picked up four students, two graduates and two undergraduates. We’re growing quickly as we get the lab set up and will hopefully take on a few more people soon. 

What are the major themes of research in your group?

As the name suggests: biomaterials, biomechanics, and biomimetics! But, more specifically, on the biomaterials side we are interested in hydrogels and hydrogel composites, primarily for applications in tissue engineering and regenerative medicine, with a little bit of recent interest in drug delivery.

We also work on the mechanical characterization of natural biological materials and biomaterials, always hydrated, with particular emphasis on nanoindentation techniques. Also, more recently, we have started computational models of blood flow and oxygen diffusion in the human placenta during pregnancy!

The third strand of our research is focused on biomimetics: materials that imitate either the materials found in nature or the processes used to make natural materials. In addition to fibrous hydrogel composites, which are soft tissue biomimics, we’ve also looked at bone and eggshell not just for medical applications but also as structural materials with small carbon footprints. 

I talked about this at TEDxCambridge (https://www.youtube.com/watch?v=RRtsmfedbR0) and also made a pretty cool video with Google and Lego (https://www.youtube.com/watch?v=WBEtUJmp05w).

How and why did you come to work in these areas?

I did my BS in Materials Science and my MS in Engineering Mechanics, so studying mechanical properties of materials is my natural research area. I further complicated things by doing my PhD in Biophysical Sciences, working on properties of natural cartilage (healthy and osteoarthritic) and bone while a graduate student. On starting my own group, I decided to add the materials synthesis aspect to materials characterization and started working on hydrogels and biomimetics.

What facilities and equipment does your lab have?

We’re just getting set up at ECU, but have a couple of low-force mechanical testing instruments and a brand new nanoindenter, along with basic wet lab small equipment. 

Although my home department is Engineering, my office and lab space are in a shared research area in the School of Dental Medicine, where there are lots of basic cell culture and cell biology facilities. I’m getting ready to purchase an electrospinning rig for making nanofibers and will continue to grow the lab’s capabilities over the next few years including with infrared spectroscopy.   

Do you have a favorite piece of kit or equipment?

The nanoindenter! I started doing my first nanoindentation experiments ‘on the side’ when I was a PhD student in the late 1990s, which means somehow I’ve been working in this area for 20 years now!

What do you think has been your most influential work to date?

When you specialize in mechanical characterization, you often get pulled into interesting collaborations with people who work in a broad range of fields. As such, my publication record looks quite eclectic, with the obvious – materials and physics journals – and the more unexpected – pregnancy/obstetrics, which has become a main research area for me, and paleontology. My most broadly read and cited work all has to do with nanoindentation measurements or modeling. 

What is the key to running a successful group?

Flexibility and working hard on the relationships you have with your students. There has to be trust in both directions. 

How do you plan to develop your group in the future?

We’re growing, since we’re new to ECU, and ECU Engineering is a relatively young department at a school with a much more established medical school. We’re just getting ready to launch a biomaterials research cluster across the university this spring, which should bring loads of great opportunities for interdisciplinary research. 

Key publications

1. M. L. Oyen and R. F. Cook. Load-displacement behavior during sharp indentation of viscous-elastic-plastic materials. J. Mater. Res. 18 (2003) 139-150. 

2. M. Galli, K. S. C. Comley, T. A. V. Shean, M. L. Oyen. Viscoelastic and poroelastic mechanical characterization of hydrated gels. J. Mater. Res. 24 (2009) 973-979. 

3. M. L. Oyen, T. A. V. Shean, D. G. T. Strange, M. Galli. Size effects in indentation of hydrated biological tissues. J. Mater. Res. 27 (2012) 245-255. 

4. B. Trappmann, J. E. Gautrot, J. T. Connelly, D. G. T. Strange, Y. Li, M. L. Oyen, M. A. Cohen Stuart, H. Boehm, B. Li, V. Vogel, J. P. Spatz, F. M. Watt, W. T. S. Huck. Extracellular-matrix tethering regulates stem-cell fate. Nature Mater. 11 (2012) 642-649. 

5. M. L. Oyen. Mechanical characterization of hydrogel materials. Inter. Mater. Rev. 59 (2014) 44-59. 

6. A. L. Butcher*, G. S. Offeddu*, M. L. Oyen. Nanofibrous hydrogel composites as mechanically robust tissue engineering scaffolds.  Trends in Biotech. 32 (2014) 564-570. (*Joint first authors.) 

7. R. Plitman Mayo, J. Olsthoorn, D. S. Charnock-Jones, G. J. Burton, M. L. Oyen. Computational modeling of the structure-function relationship in human placental terminal villi. J. Biomech. 49 (2016) 3780-3787. 

8. K. Tonsomboon, A. L. Butcher, M. L. Oyen. Strong and tough nanofibrous hydrogel composites based on biomimetic principles. Mater. Sci. Eng. C 72 (2017) 220-227. 

9. Y. Abbas, C. M. Oefner, W. J. Polacheck, L. Gardner, L. Farrell, A. Sharkey, R. Kamm, A. Moffett, M. L. Oyen. A microfluidics assay to study invasion of human placental trophoblast cells.  J. Royal Soc. Interface 14 (2017) 20170131. 

10. G. S. Offeddu, I. Mela, P. Jeggle, R. M. Henderson, S. K. Smoukov, M. L. Oyen. Cartilage-like electrostatic stiffening of responsive cryogel scaffolds. Scientific Reports 7 (2017) 42948.