Engineering Newsletter

Edward Guo | Biomedical Engineering

Ten million Americans suffer from osteoporosis, a gradual weakening of the bones that can lead to fractures, loss of mobility and independence, and depression. Another 18 million suffer from low bone mass. No cure exists for either condition. Doctors simply tell patients to consume enough calcium and vitamin D, to do weight-bearing exercise, and to avoid smoking. Sometimes they also prescribe medications, including bisophosphonates (Fosamax, Actonel and Boniva), selective estrogen receptor modulators (Evista), or hormones such as parathyroid hormone (Forteo). But all come with side effects, and none are free. The only bone builder on the market, Forteo, costs $8,000 a year and requires daily shots for two years.

X. Edward Guo, director of Columbia’s Bone Bioengineering Laboratory, is trying to figure out how to prevent and treat osteoporosis from both engineering analysis and biological perspectives. To do so, he and his team are analyzing high-resolution 3D images of bone from both laboratory samples and non-invasive patients’ images to figure out how to better predict fracture risk in patients and monitor efficacy of anti-osteoporosis treatment. With several multi-million-dollar grants supported by the National Institutes of Health (NIH) and working with endocrinologists Drs. Elizabeth Shane and John Bilezikian at Columbia University’s College of Physicians and Surgeons, and Drs. Felix Wehrli at the University of Pennsylvania, they have developed novel imaging analysis and modeling techniques to identify microstructural deteriorations in bone and have translated these technologies in clinical assessments of osteoporosis. From biological front, Guo and his team use a battery of advanced imaging and nano technologies to explore how mature bone cells (osteocytes) control bone-forming cells (osteoblasts) and cells that break down bone (osteoclasts). They can help ward off bone fragility as they better understand how the commander-in-chief mature bone cells communicate with (and boss around) the cells that form, and destroy, skeletal tissue. Guo and his team also plan to use their knowledge to better understand osteoporosis and bone loss in outer space.

In the future, Guo and his team hope that doctors can prescribe drugs that would help mature bone cells recruit more bone-forming cells and snub the bone-destroying ones. Such drugs would be a boon to an aging population. After all, women over 50 can lose as much as 20 percent of their bone mass around menopause. Perhaps some day everyone could get drugs at a younger age to prevent later bone loss.

Guo received his PhD from the Harvard-MIT division of health sciences and technology. Working with Professor Paul Sajda from Biomedical Engineering, and Professor Rafael Yuste of Biological Sciences, Guo has recently won a highly competitive National Institutes of Health (NIH) Challenge Grant. The two-year $915,108 RC1 Challenge Grant “Implicit Learning in Osteocyte Network under Mechanical Loading” will support Guo’s work in testing the novel hypothesis that an osteocyte network may function in a similar way as a neuronal network and plays an important role in mechanical memory.

He has also received a new five-year $1.7 million grant to examine how mechanical loading influences bone formation and mechanical integrity of bone tissue. The project, “Mechanobiology of 3D Trabecular Bone Explants,” will provide information about the mechanism of mechanical loading in bone tissue, which is critical in understanding osteoporosis and bone loss in space.