OIRM Team Hunts for Effective Ways to Deliver Cell Treatments for Back Pain

If you’re over 30, chances are you’ve experienced some form of back pain; four out of five Canadians will at least once in our lives. Chronic back pain – which affects one in eight of us – can have profound consequences on systemic and mental health, as well as quality of life. Currently, however, there are few effective treatments for it.

Dr. Lauren Flynn, Professor of Chemical & Biochemical Engineering at Western University and OIRM New Ideas researcher, wants to change that prognosis.

Q: What are the drivers of chronic back pain, and why is it difficult to treat?

Dr. Flynn: Unfortunately, the causes of back pain are not particularly well understood – in the majority of cases, the root cause cannot be identified. In many cases, we think the pain is ultimately related to the degeneration of intervertebral discs, which are the connective tissues that separate the vertebrae in the spine.

The bad news is, there are no effective disease modifying therapies for intervertebral disc degeneration (IDD), and so most people are treated with measures such as physiotherapy to strengthen the back, or pain medication. For many patients, these aren’t helpful, and the pain is a recurrent, debilitating problem.

There are some surgical options available when conservative management fails, but they come with a high risk for complications – and any procedure to treat injury at a certain location can result in altered biomechanics in the spine that can create more problems in the long term.

Q: What role might regenerative medicine play in treating chronic back pain in the future?

Dr. Flynn: There has been a lot of interest in the potential for developing a cell-based therapy to treat IDD. The intervertebral disc is comprised of three main components – an outer fibrous layer called the annulus fibrosus, a Jell-O-like substance inside the disc called the nucleus pulposus (NP), and the cartilaginous end plates, which are thin layers of cartilage adjacent to the vertebrae. It is believed that degenerative events initially occur due to changes in that inner, gelatinous NP. So, researchers have been interested in delivering stem cell populations into that area to replace damaged cells and restore function.

The limitation of this approach is that very little research has looked at better ways to deliver these cells – when you put a cell population into a diseased microenvironment, there is no guarantee they will function properly. Our goal is to develop better delivery mechanisms that will hopefully instruct the cell populations to function in a more regenerative manner.

Q: What are those mechanisms?

Dr. Flynn: We’re trying to develop a tissue-specific approach that mimics the native environment of the healthy NP, delivering cells in a gel-like material – essentially, a protective shell or scaffold – that provides them with many of the necessary biological cues needed to function adequately. It’s also possible that this delivery platform could even work on its own to restore mechanical function and provide a healthier environment for the cells that are already present within the NP.

Q: Tell us about the multidisciplinary approach this project takes.

Dr. Flynn: Our team is highly collaborative and has a unique combination of interdisciplinary expertise. My strength is in the design of naturally-derived materials – in this case, extracting extracellular matrix proteins from NP tissue that can function as a cell-instructive scaffold. While their bioactive properties are highly promising, these NP proteins on their own don’t offer much flexibility in tuning our delivery system. In collaboration with Dr. Brian Amsden at Queen’s University, an expert in polymeric biomaterials, we have developed injectable hydrogels that allow us to encapsulate the NP proteins in combination with cell populations to generate composites that mimic the native NP and support the long-term retention, survival and function of the encapsulated cells. With co-principal investigator Dr. Cheryle Séguin at Western, an expert in spine biology, we are characterizing the cellular response to the scaffolds to more fully understand how the NP proteins can be applied to establish a microenvironment that promotes the desired tissue regeneration.

Q: What do you see as the ultimate results of this project?

Dr. Flynn: In the shorter term, we hope we can use these platforms for more basic cell biology studies, creating an environment that’s similar to what is seen in the body so we can better understand the mechanisms of IDD. If our testing shows that the scaffolds we are developing can successfully direct the responsive cells to have a more pro-regenerative function, our hope would be to one day develop an injectable cell therapy that works on its own or in combination with cell populations.