Injecting hope with hydrogels

Hanyang University. Korea: Professor Kuen-yong Lee of the Department of Bioengineering is a researcher whose main areas of interest lie in design, modification, and characterization of polymeric biomaterials for drug delivery and tissue engineering applications. Specifically, Lee mainly focused his interests on biomaterials, biomedical polymers, biodegradable polymers, polymers for tissue engineering, and polymers for protein and gene delivery. Controlled Release Society, Tissue Engineering Society, and Polymer Society of Korea. His recent paper, ‘Ionically cross-linkable hyaluronate-based hydrogels for injectable cell delivery’ sheds further light into his field of research and opens up new possibilities in the realm of bioengineering.


Currently, tissue regeneration and gene delivery are becoming increasingly important issues within the medical field as well as other areas, such as cosmetics. As people grow older, their bodies slowly deteriorate. Joints, especially the knees, become weaker and wrinkles start to appear. In addition, people who suffer from severe ailments might be in dire need of new tissues and cells. It is now possible in modern society to alleviate these sorts of problems due to the advancement of technology. In other words, Lee’s research in tissue regeneration and drug delivery will greatly benefit the elderly and sick.
Before explaining Lee’s research methods, it is essential to fully understand the basic concepts and key words that are used throughout the paper. To begin with, hydrogels are gels that contain water. Hydrogels act as a carrier for the cells necessary for the recovery of a patient. They are formed by cross-linking polymer chains so that it creates a network structure.
There are two ways to cross-link, physically and chemically. In the case of the physical method, its advantages include having no negative side-effects since it does not involve chemicals of any kind. Yet, one of its downsides is that it is relatively easier to break apart compared to the chemical method. On the other hand, cross-linking chemically results in a more strong and stable structure. Hence, it is less likely to fall apart. However, it is possibly harmful and may lead to unexpected negative consequences to the human body.
In his experiments, Lee strived to create Ionically cross-linkable hyaluronate-based hydrogels. There were complications as the fundamental problem was the fact that hyaluronate could only be cross-linked chemically. To reiterate, it was virtually impossible to cross-link hyaluronate through the physical method. He overcame this hurdle by adding g-alginate, which enabled him to physically cross-link with the hydrogel effectively. Consequently, this made the end result safe to inject into animals. Lee subsequently proceeded to inject lab rats with his substance for cell delivery and monitored them for about 6 weeks. He discovered later on that he succeeded in delivering the cells that resulted in cartilage regeneration. Thus, Lee made a huge leap forward in tissue regeneration.
Lee’s research has numerous potential applications other than the medical realm. Utilizing the cell-delivering hydrogels, this discovery is beneficial to plastic surgery as well. Specifically, it greatly assists in removing fillers that are commonly used in cosmetic surgeries to enhance people’s appearance. However, when things go awry or the customer desires to have their filler removed, it was a difficult process. Now, through Lee’s discovery fillers injected through his hydrogels can be removed easily by simply melting away the ions in the gel, which is totally harmless and does not entail any side effects. Therefore, in this case, what was once a negative aspect of physical cross-linking, that is to say, its relative ease of removal, turned out to be actually favorable.
Lee mentioned that his future plans were to further experiment on his hydrogels, steadily moving on to clinical trials. “This is not the end yet, we still have much to do in order to ensure that it is fully safe and practical,” Lee commented. He stated that there are so many expected uses and benefits from his research, “This hydrogel will be a more effective delivery platform for various injections including genes, cells, and drugs. With this, it will be a lot easier to inject treatments into patients with diabetes or cancer.” Lee wishes students to do what they truly enjoy for only then will there be better results. He concluded the interview by claiming, “Not every experiment will go according to plan, the same goes with life, so do not be let down by failure. Try to plan ahead, concentrating on getting the job done as quickly and efficiently, as possible.”