Laser Focus

Medical researchers believe that they will soon be able to use stem cells to treat patients with severely damaged or malformed bones, but there are still some major hurdles in making that kind of therapy a reality. 

Assistant Professor Luke Mortensen, a researcher in the University of Georgia College of Agricultural and Environmental Sciences’ Department of Animal and Dairy Sciences, UGA College of Engineering and the UGA Regenerative Bioscience Center, is developing imaging technologies and ways of pinpointing the delivery of stem cells to damaged bones that make these types of therapies more likely to work. 

Mortensen joined the faculty at UGA in 2014 after finishing a postdoctoral fellowship at Harvard Medical School, where he developed a laser-imaging technology that will allow the design of unique cell therapies for bone repair. 

Mortensen, a biomedical engineer by training, is working to program mesenchymal stem cells — stem cells that can specialize in making and repairing skeletal tissues — to be better adapted to attach to the portion of the bone that needs to be repaired. Once attached to this “homing site” the mesenchymal cells start to specialize and replicate based on the cell type at the homing site.

This therapy could be used to treat bone diseases like osteoporosis, where the bone becomes overly porous; hypophosphatasia, where the bone is overly soft; or to treat severely broken or shattered bones, speeding the healing process. 

“When you administer these cells, only a small number of these cells actually get where you want them to go and only a small number do what you want them to do,” Mortensen said. “We’re working on ways to improve the potency of the cells before we put them into the patient — how can we create a cell therapy and have it always function where and how we want it to function.” 

Mortensen is collaborating with scientists at the Georgia Institute of Technology, University of Wisconsin and University of Puerto Rico on improving cell biomanufacturing techniques to increase the efficacy of individual cell treatments. 

For the procedure to work, Mortensen had to develop an imaging technology that would allow him a clearer view of how the newly introduced mesenchymal stem cells and the damaged bone were interacting. 

To this end he developed a laser microscope which shoots photons at the bones in question, producing a real-time image of the way cells are working inside the body. 

“Our microscopes allow us to see inside the bone and focus on certain aspects of the bone, like the collagen mesh in the bone, to visualize what’s happening inside,” he said. “As we put new cells in there, we can see as they move around, as they hopefully turn into bone and as they change their behavior. We can visualize that in real time.”

Knowing what is happening inside the bone is critical to fine-tuning these therapies. •