Associate Professor, Department of Mechanical Engineering
Phone: (250) 721-7303
Research area: tissue engineering,regenerative medicine,biomaterials scaffolds for controlling stem cell differentiation
It is not difficult to imagine Dr. Stephanie Willerth as the five-year-old kid who, wanting nothing more than to be a professor with her own lab, had but two items on her Christmas wish list – a chemistry set and two tickets to the Orange Bowl.
Twenty-five years later, Dr. Willerth is an assistant professor of biomedical engineering and the head of the University of Victoria’s state-of-the-art Willerth Laboratory. She leads a team of innovative researchers in the areas of tissue engineering and regenerative medicine.
With the recent discovery of induced pluripotent cells (iPS) – adult cells that have been taken directly from a human source and then modified in order to regain their original embryonic properties - scientists now have the ability to work with cell lines that are both less controversial and less prone to rejection by the immune system.
Willerth is studying how and why these stem cells grow into one of the 200 plus mature cell types found in the human body. By focusing on two key areas, 3D bioactive scaffolding and novel drug delivery systems, Willerth hopes to revamp the future of personalized medicine.
Willerth and colleagues are currently studying the growth of iPS and embryonic stem cells (ES) on 3D matrices that essentially act as bioactive scaffolding. These structures provide a far superior environment for directing stem cell growth than traditional 2D cultures.
By studying stem cell behavior in the presence of chemical cues, such as retinoic acid, and proteins that include neurotrophin 3 and sonic hedgehog (named after the classic videogame), Willerth is generating valuable data on how these iPS and ES cells differentiate.
Along with partner organization iCORD, Willerth is working to replicate the ideal conditions required for the production of neurons, finicky cells that tend to take a back seat to astrocytes and oligocytes, the default cells of the nervous system.
While Willerth’s research has yet to see human clinical trials, the use of 3D matrices has seen post transplantation cell survival rates skyrocket to 90 per cent from five. This is promising news for Willerth, who has high hopes of transplanting scaffolds seeded with stem cells directly into nerve injury sites.
Willerth’s lab is also investigating the viability of what she refers to as “our crazy idea”, the development of a diffusion and affinity-based drug delivery system capable of controlling the release rate of target molecules designed to promote tissue repair.
This novel idea is based on the non-covalent interactions between the target molecule and the scaffold material, which allow for a more controlled release of medication than the random processes involved in simple diffusion.
Willerth hopes to design drug delivery systems that are capable of being introduced to an injury site just once, yet also capable of continuously releasing the factors needed for tissue regrowth and repair.
Specifically, the Willerth lab is studying the impact of peptide-bound heat shock proteins (HSPs) on nerve injury sites. The process involves the incorporation of peptides, along with electrostatically-bound HSPs, into a fibrin scaffold through enzymatic activity.
Because the HSPs are not physically tethered to the scaffold, an injured nerve cell should, in theory, be capable of taking up the vital proteins over time. The scaffold, however, provides an element of protection that prevents the HSPs from being quickly washed away by cerebrospinal fluid.
Willerth is most excited about the thought of developing new therapeutic treatments where current therapies fall short. Her ultimate goal – to restore the function lost to devastating spinal cord injuries. And while this may seem like a lofty goal, Dr. Willerth seems to be in no danger of giving up anytime soon.