Lower-back pain causes distress for millions of people, but this enormous problem often can be traced to a tiny piece of tissue — a cushioning disc between the vertebrae in the spine.
As a person ages, intervertebral discs frequently degenerate, causing the vertebrae to rub together, resulting in chronic pain that can disrupt almost every facet of everyday life, ranging from work tasks to sleep.
To help relieve this suffering, researchers in Rowan University’s College of Engineering and College of Science and Mathematics are zeroing in on these worn discs, developing a new material that may someday help rebuild damaged tissues.
Research has shown that new cells infused into the disc can help develop new tissues, but it is difficult to keep the cells in place. “The problem is there are many materials that work, but if you try to implant them into a disc, research has shown they most likely will be expelled,” said Dr. Jennifer Vernengo, Assistant Professor of Chemical Engineering.
Therefore, Rowan researchers are exploring ways to develop a three-dimensional hydrogel scaffold containing these cells that begins as a liquid and will become more solid after it is injected into a damaged intervertebral disc and reaches body temperature.
Vernengo, along with Dr. Cristina Iftode, Associate Professor of Biological Sciences, and Dr. Jennifer Kadlowec, Professor of Mechanical Engineering, are working to develop a material that will adhere to surrounding tissue, remain in place and enable cells to regenerate healthy tissue. However, such a material must enable the new cells to survive. “Existing adhesive polymers are very toxic to cells,” Vernengo said.
As Vernengo works with her team of engineering students to develop the polymer, Kadlowec performs mechanical tests on the material.
“Mechanical tests mimicking loading conditions in the body are performed as well as tests to determine adhesive strength,” Kadlowec said. “We want to be sure that the polymer behaves like native tissue and is not expelled if implanted.”
Meanwhile, Iftode and her team collaborate with Vernengo and her students to test the polymer to determine whether cells can survive within the material and how long it will take them to regenerate and develop new tissue.
Strength in Collaboration
The researchers’ diverse backgrounds are strengthening this research. “Cristina’s expertise in biology is very complementary to my expertise in materials,” Vernengo said.
“Collaboration is really very powerful because a different perspective on a common goal is always beneficial,” Iftode said.
This partnership not only fortifies their work, but it offers students majoring in different disciplines the opportunity to interact with each other and share their data. “The chemical engineering students would not be exposed to that in a traditional chemical engineering curriculum,” Vernengo said. “This gives them a more competitive edge and strengthens their background and professional development, making them more marketable for jobs in the biomedical engineering field.”
Collaborations also expose students to new opportunities. “It opens their eyes to the possibilities of doing interdisciplinary work, and they may not have been aware of that before,” Iftode said. “My students often sought more traditional types of Ph.D.s, and now some are talking about pursuing specializations in the areas of regenerative medicine and bioengineering.”
The researchers have applied for a National Institutes of Health grant for their continuing work. Their preliminary research was published in the January 2013 issue of the Journal of Materials Science: Materials in Medicine.
After the teams optimize their hydrogel formulation with control cell lines, they will switch to using adult stem cells. Control cell lines are well established and characterized cell lines that are easy to manipulate, generate highly reproducible data and are cheaper to maintain; thus, they are preferred in preliminary testing. But tissue regeneration is possible only with stem cells. In this sense, the adult stem cells are almost as potent as the embryonic stem cells for disc tissue reconstruction, without the controversial ethical implications of the latter.
As their next step, they hope to collaborate with researchers at Cooper Medical School of Rowan University to obtain fat (adipose) stem cells derived from liposuction tissue. “Surplus body fat is a really good source of adult stem cells, which can be isolated, proliferated and then used to populate the scaffold we develop,” Iftode said. “Then these scaffold-embedded stem cells will be exposed to a cocktail of growth factors that will induce them to differentiate into the type of cells that mimic the cells in the intervertebral disc.”
Although research is still in preliminary stages, it may ultimately go a long way in solving a widespread problem. “It addresses a real need in terms of being able to translate tissue engineering and regenerative medicine into actually helping people with lower back pain, which is one of the most common medical problems,” Vernengo said. “I think it will make an important impact down the road.”
The project is one of numerous studies conducted by teams at Rowan, which continues to grow its research initiatives, many of which are funded by such organizations as the National Science Foundation, National Institutes of Health and Fortune 500 companies.
“This work is a wonderful example of students and faculty collaborating on practical research that provides solutions to real problems. This has the potential to change the lives of our neighbors who suffer from chronic back pain,” said Dr. Anthony Lowman, dean of the College of Engineering.