Hyunjoon Kong: Pioneering advances in nanobiomaterials for diagnosis and therapies
This profile originally appeared in the Fall/Winter 2016 issue of Mass Transfer, the magazine for alumni and friends of Chemical and Biomolecular Engineering at Illinois. For a listing of all our faculty members, please visit our directory or explore the department’s research pages for overviews of our groundbreaking research programs.
Self-folding hybrid materials, bio-inspired nanoprobes and nanomedicines, revascularization patches, cardiovascular organoids. Welcome to the futuristic world of Professor Hyunjoon Kong.
Since he joined the University of Illinois Department of Chemical and Biomolecular Engineering faculty in 2007, Kong has made a name for himself around the world as an innovative collaborator in advanced material systems. Just this year he earned accolades such as the Dean’s Award for Excellence in Research from the College of Engineering and the Campus Distinguished Promotion Award. This August he was promoted to full Professor.
At Illinois he has developed several bio-inspired material systems useful for molecular and cell therapies of vascular diseases, control of biotransports, and organoid/tissue engineering. Although some engineering professors prefer to develop technology and launch their own companies to market that technology or product, Kong has taken a different approach.
“I am more interested in licensing technology so I can spend more time developing new materials in futuristic ways. At the same time, I hope to collaborate with people in industry who can mature our technology,” he said.
Early focus on rheology
Kong grew up in Seoul, South Korea. At Hanyang University, he studied in the department of industrial chemistry (now the department of chemical engineering) for his B.S. His father was a pharmacist and often spoke about synthesis and physiological activities of drug molecules. Under this environment, Kong became interested in studying chemistry and chemical engineering. In 1995, he came to the U.S. as a graduate student at the University of Michigan’s Macromolecular Science and Engineering Program, an interdisciplinary program in the college of engineering with a focus on polymer science and engineering.
He studied colloidal rheology, specifically the effect of colloidal interaction on the deformation and flow of colloidal particle suspension (called “sol”) and the subsequent mechanical property of cured materials (called “gel”). The “sol” he worked with was a fresh cementitious mix and the “gel” he worked with was the flexible and tough cement composite. As a student, Kong contributed to developing various cementitious materials with controlled fluidity and ductility. Some of the products he developed—a self- compacting cementitious composite and a sprayable composite—are being used today to repair old infrastructures, including bridges and highways.
With two different advisors, one an expert in fluid mechanics and the other an expert in fracture mechanics, Kong was able to gain a better understanding on rheology-structure properties and their relationship towards enhanced material performance.
As a postdoctoral researcher at Michigan and a research associate at Harvard University, Kong had an opportunity to translate what he learned with complex fluids and construction materials into the design of biomaterials used for “living” tissue regeneration.
“I started to realize that lots of materials, including concrete, which we have been using in our daily lives are inspired by our body structure. What I started to think was, if I had chance to learn more about tissue engineering, which aims to recreate functional tissue by orchestrating biomolecules, cells, and matrices, I can use that understanding to develop advanced materials systems in my own career. That’s when I changed my direction,” he said.
Creative collaborations
Kong joined the University of Illinois as an assistant professor in 2007. What appealed to him about the university was its reputation for intense, innovative engineering research and its interdisciplinary institutions. He knew it would be a great place to establish strong ties with other faculty and for launching an independent research program.
As a side note, the first time he had heard about the university was when he was around 10 years old. One of his uncles, Dr. Young-Il Kong, an English Literature professor and later a president of Kyung Hee University in Korea, was a visiting scholar at Illinois.
At Illinois, Kong established a research program that focuses on the synthesis, characterization, and processing of nanobiomaterials for diagnostic imaging and molecular/cell therapies of vascular diseases, a major health problem in the U.S. He is a core member of the Regenerative Biology and Tissue Research Theme at the Carl R. Woese Institute for Genomic Biology. He is also affiliated with the Departments of Bioengineering and Pathobiology, the Neuroscience Program, the Center for Biophysics and Quantitative Biology, the Micro and Nanotechnology Lab, and Beckman Institute.
He has authored or co-authored more than 115 research papers and has more than five issued and pending patent applications. Earlier this year, he joined the editorial board of the journal Biomaterials. He also is acting director of the graduate program in bioengineering and an executive committee member of the neuroscience program.
He has taught the courses Principles of Chemical Engineering, Thermodynamics, and Biotransport, a new course he created after arriving on campus. The biotransport course investigates the roles that the transports of mass, energy, and momentum play in the function of living systems such as cells, tissues, and organs.
“The course is a nice integration between physiology and traditional chemical engineering principles. We can use our chemical engineering principles to understand physiology in a quantitative manner and to develop advanced engineering systems,” he said.
Kong partners with faculty across campus and the world on a variety of futuristic research projects. He has been working with Steve Zimmerman, Roger Adams Professor of Chemistry, and Dr. Sanjay Misra and Dr. Y.S. Prakash, medical doctors at the Mayo Clinic, to develop nanomedicine that can detect vascular defects characterized by clogging, swelling, or leakage, similar to problems found in pipelines of chemical factories. If found during its early stage, vascular defects can be easily treated with surgical or biomedical tools, he said.
“But it’s not easy to find these defects. It’s not easy to treat them, if too late. Therefore, what we are trying to do is develop a small nanoparticle that can be injected into the circulation to probe for defects. When scanned by an MRI, it can highlight those defects,” Kong explained.
He and his fellow researchers also want to deliver medication via the probing nanoparticles, controlling the release of the drug or transport of therapeutic stem cells for more enhanced treatment of diseased tissue. They have been demonstrating some success in their tests with lab mice. Next, Kong and his fellow researchers will talk with potential collaborators who are interested in testing the technology in large animals and eventually human patients.
In particular, Kong has been utilizing intermolecular self-assembly techniques to synthesize nanoprobes or nanomedicine with non-spherical geometry similar to rod-shaped E-Coli bacteria and parasites. Unlike sphere-shaped nanoprobes, these non-spherical particles could offer better contact and interaction with targeted tissue while traveling through circulation, Kong said. For this project, he also has partnered with Charles Sing, Assistant Professor of Chemical and Biomolecular Engineering. Separately, he also started a new National Institutes of Health project that aims to use these nanocarriers for treatment of skeletal muscle with Marni Boppart, a professor in the Department of Kinesiology and Community Health.
For years Kong has been investigating how biological cells communicate with their microenvironments including biomolecules, matrices, and neighboring cells, and in turn undergo emergent behaviors responsible for building “living” tissue and organs. In particular, he has been formulating hydrogel materials, which can mimic microstructure and chemical/mechanical properties of an extracellular matrix. Using these hydrogels, he engineered miniature organs, termed “organoids,” which can partially reproduce structure and function of organs such as the heart, nerves, and muscles.
In particular, he has been recently focusing on engineering a neuron-muscle interface called a neuromuscular junction, which controls muscle locomotion with signals from the brain. He is making efforts to incorporate the neuromuscular junction into biological machinery, together with his on- campus collaborators Rashid Bashir (Professor of Bioengineering), Taher Saif (Professor of Mechanical Science and Engineering), Martha Gillette (Professor of Molecular & Cell Biology), and Gabriel Popescu (Professor of Electrical and Computer Engineering).
“What we’re trying to develop is an in vitro platform especially for the motor neurons connected to the muscle. If we can engineer that neuromuscular function, it can also be part of the biological machine which has been invented by my collaborators,” Kong said.
He has been conducting this research through a multi-institution effort known as the Emergent Behaviors of Integrated Cellular Systems, or EBICS. In 2010, the research group, of which Kong is a member, received $25 million from the National Science Foundation to build living, multicellular machines to solve environmental, health and security problems. They recently received another $25 million to continue this research for another five years.
Kong is further advancing so-called “organoids” to simulate human physiology. “The basic idea is whenever we develop new medicine and its nano or micro-sized carriers in our school setting, we can test it in a mouse. But the mouse’s physiological environment is very different from a human’s. The question then becomes, ‘Can we create an in vitro tissue model which can provide an environment closer to a human? Organoids mimic human tissue much closer,” he said.
To pursue this goal, Kong is working with Reid T. Milner Professor Deborah Leckband, who investigates how cells communicate through cell adhesion, on a project that aims to interrogate how cell-cell adhesion influences development of and fluid transports through organoids.
In another collaboration, Kong and researchers at the Korea Institute of Science and Technology (KIST) in South Korea and Germany started a project aiming to engineer a liver organoid useful for studying environmental impacts on marine organisms, including fish. Because of growing concern over non-metabolized pharmaceuticals potentially polluting rivers and streams, scientists want to understand how these drug molecules can affect reproduction and metabolism of fish. Due to governmental regulation on the use of fish in research, the fish liver organoid will be an invaluable tool to both fundamental and applied bioscientists.
Additionally, Kong has been assembling a material that can regulate regeneration of new vascular networks in tissue damaged by accidents, surgery, or diseases. One highlight was a hydrogel patch that can recreate microvascular networks with similar spatial organization of original microvascular networks and in turn ensure recovery of perfusion. He used a 3D printer to assemble the patch together with Professor Rashid Bashir. This patch was granted a U.S. patent. He is testing therapeutic efficacy of the patch to treat cardiac infarction and non-healing wounds. Furthermore, he explores a hydrogel that can change shape in response to external stimuli. He is now assembling hydrogels that can take the shape of a tube or ring via self-folding, and then revert back to their original shape. By doing so, he will be able to non-invasively deliver his therapeutic hydrogel implants inside a body.
Because he has a foot in two worlds— engineering and medicine—Kong was a natural choice to co-direct course development for the new Carle Illinois College of Medicine. It is the first college of medicine in the U.S. specifically designed at the intersection of engineering and medicine.
Kong said he appreciates continued engagement and collaboration with medical doctors, who provide valuable insight and feedback on technology he is developing. No engineer wants to develop technology that is useless.
“Once I talk with the medical doctors, I have a clearer idea about what I have to do. If we have a successful medical school, it will accelerate the progress of our work,” Kong said.