In our daily lives and as we pursue our careers, it is common to encounter one or two or even three fields that we find interesting. However, the forefront of scientific research is becoming increasingly more interdisciplinary, incorporating a wide range of different fields, which sometimes seem completely unrelated. The field of Biomedical Imaging is an example of this, as it is the subject of extensive research in order to replace conventional imaging methodologies with cheaper, less-invasive alternatives. Although in this particular case, the research is grounded in physics and biology, there is a significant presence of biophysics, biochemistry, engineering, medicine, and computer science. Professor Arjun G. Yodh is a renowned physics professor at the University of Pennsylvania who is passionate about bringing important technologies such as this within reach of as many patients as possible. On Thursday, he gave a plenary speech at Nano Korea 2019 called “Biophotonics with Diffuse Light: Basic Ideas, Status, and Opportunities” to showcase his findings on biomedical imaging and his ideas on applying nanotechnology to this field. Although he is a physicist, he enjoys the interdisciplinary nature of his work, as he “learns to learn.” To see his profile, publications, and patents, go to https://www.physics.upenn.edu/yodhlab/index.html.
Q: Your research involves both biology and physics, which is fascinating to me because at my school, there’s no one taking both biology and physics. They seem to have almost nothing in common. You started with a degree in physics, so what led you to do biology as well?
A: Ok, so let me first say that nowadays, there is biophysics in many places. Even where I work there is a concentration of biophysics. But I liked physics the best. I like lasers and I actually started in atomic physics and then I learned something about condensed matter physics – but all as I was using optics. Then I met someone who was working on multiple light scattering, but on physics problems. So I learned that, and I learned about soft materials, after which I started talking to a professor at UPenn named Britton Chance. He’s deceased now, but he’s famous. After talking for two years, we decided to pursue some good opportunities and take some students together. And so I learned about the the biomedical field … biophysics and biomedical physiology were all learning “on the fly.” But it’s ok, because you learn to learn. It actually makes it very interesting for me.
Q: From my research, I know you are passionate about replacing commonly used imaging procedures such as X-ray mammography, MRI and PET with diffuse optical methods that you have been researching, as they are “[comparatively] inexpensive, non-ionizing, rapid, portable and non-invasive.” What are the largest obstacles in the way of bringing in these new technologies into hospitals? What are some pros and cons of this?
A: I think optical methods will be good for monitoring patients; imaging doesn’t have the resolution needed for deep tissues. On the other hand, it can provide complementary information to techniques currently used in hospitals. One obstacle is to get people to start using them in early stage studies, like we’re doing, and to show that there are real and practical reasons to do so. So that’s one thing. Another thing is that we still want to make it cheaper, and in order to keep doing that, get sustained support. But a big part of it is to get people to try new things. And also make progress.
Q. You mentioned that there are many potential nanoparticles – such as gold, porphyrin, dendrimer and silicon – for imaging and therapy. In your opinion, which nanoparticles are best for your diffuse optical spectroscopy/ diffuse correlation spectroscopy?
A: So you have to think about what you want to learn. To me, a really important thing for the optical side of it is to increase contrast. So you want particles that go to tumors that are optically active, and if possible have an enhanced optical property. But also, you’re looking at therapies,to make better therapies, and release reporters. There are a lot of ideas but it’s a long road to get it approved by the FDA. It’s a long road and not very many drugs have been approved, even after people have been talking about it for a long time. ICG is one of the main ones. That’s the only one – that was already being used!
Q: You’ve pointed out that “Biomedical optics is a highly interdisciplinary field” that includes “physics, biophysics, biochemistry, engineering, biology, medicine, and computer science.” Today, during your talk you also linked material chemistry and included nanotechnology as well. In order to do this, it seems as though there will be one or two fields that anchor what you’re doing (so you know those fields really well) and you draw from the other fields what you need. I expect there will be a lot of collaborations… How do you keep the collaborations anchored to the main one or two fields? In other words, how do you keep the collaborations from getting out of control?
A: I’m not worried about that very much. I know what I know – the physics and mathematics side, instrumentation, experiments. But I’m not a chemist. So if you’re going to design Porphyrin particles you need to be good at chemistry, and so I have to collaborate. And for that matter, I need to collaborate with clinicians, right? They understand all the physiological problems. I don’t worry about it spiraling out. It’s not one of my big worries.
Q: In high school, we have to choose two out of the three sciences. However, you show in your research how important it is to have knowledge in all 3 sciences. I really think that this is the wave of the future. Do you think that it’s misguided of schools to force students to choose just two out of the three sciences?
A: Like I said, in our Physics Department, there are different combinations which is sort of pure physics, or biophysics, there’s even physics for business. So I think the trend is to be broader. I think there is a value to learning a discipline, you know. Some people have to learn it well. And it’s hard to learn it well if you’re doing too many things. So that’s probably part of the motivation. You have a long life, and like I said you learn to learn.
Q: Do you think that the era of doing research in just one field is over? That is, do you think good/relevant science now is almost always interdisciplinary?
A: That’s an absolute statement. I mean, I think that there’s a trend towards more interdisciplinary activity but I don’t think that the number of people doing pure physics, per se, or pure biology is going to go to zero. It’s going to be more mixed, and I don’t want to make a blanket statement, like an era change. A lot of the frontiers are at the boundaries of the fields. It’s beneficial to know a little bit about both, but I still do feel that, if we’re contributing to a project, we need to be the ones who know the physics, because it’s not going to be anybody else.
Interview by Spencer Lee / Seoul Foreign School (SFS)