Investigating alternatives to bone grafts
For Harrison Mackler '07, active learning combines research, mentoring and the opportunity to one day help others
By Anne Gibson Ph.D. '95
Photos by Rob Carlin
Four years ago, Harrison Mackler '07 was a high-school student from Longmeadow, Mass., participating in Clark's Summer Science Program. This year, the Clark biology major, who is now conducting cutting-edge research on bone tissue engineering, came full circle, serving as mentor and inspiration to this year's crop of Summer Science students.
“Harrison was a great role model,” says 2006 Summer Science student Duncan Moore. Jen Kao, a student from China who had traveled to the U.S. to participate, agrees.
“I'm also planning to go into science.” Kao explains. “Working with Harrison, who's been through everything I am—and will be—going through, helped me know what to expect, what's important, and how to make decisions that I won't regret.”
Mackler, whose official role in this year's Summer Science Program was as a resident adviser, began participating in research during his first year at Clark on the advice of one of his instructors in the Summer Science Program. For this year's students, Mackler created a slide show explaining the research project that he had begun earlier in the spring semester. Clark's London Internship Program had matched Harrison, who is interested in dentistry and science research, with Lucy Di Silvio of the Department of Biomaterials and Biomimetics at King's College London Dental School. There Harrison, working in Di Silvio's lab alongside Ph.D. students, became involved in research aimed at developing alternatives to traditional bone grafts.
An alternative to bone grafts Bone can be damaged or incorrectly formed as a result of trauma, birth defects like cleft palates, or diseases such as osteoporosis and cancer. Traditional bone grafts use bone either from the patient's body or from bone donors, options which can be unsatisfactory. Sometimes the patient cannot supply the amount of bone needed, while donated bone can be rejected after it's implanted in the patient.
The research in which Mackler is participating involves the use of mesenchymal stem cells found in adult bone marrow. By exposing them to chemical stimuli such as natural hormones and vitamins, scientists have learned how to trigger the cells to develop into many cell types including bone cells. The aim of Mackler's project is to evaluate the growth and differentiation of these cells on a synthetic, biodegradable support structure, or scaffold, on which the new bone cells could grow outside the transplant recipient. The scaffolds, produced in London, are porous and resemble the mineral component of bone. The ultimate goal for tissue engineers is to develop a scaffold that could be sized and shaped to custom fit the wounded area of bone in the patient. When a sufficient quantity of bone has grown on the scaffold, it would then be implanted in the patient.
At the end of the spring internship, Di Silvio helped Mackler design a program of research that he could continue at Clark under the mentorship of his faculty adviser, Clark biologist Timothy Lyerla. Mackler explains that Lyerla's expertise in cell culture, which involves taking living cells and manipulating them in a laboratory setting, is a good fit with his bone graft alternative research.
“Dr. Lyerla supervises my research because he's an expert in cell culture,” Mackler says. “Even though he works with mouse lung cells, our techniques are very similar. It turns out that there is a lot of overlap because lung and bone tissue are composed of many of the same proteins because they are both types of connective tissues. The proteins we look for are the markers of tissue formation. Dr. Lyerla guides me 100 percent of the way because he is so experienced at growing and manipulating cells in the lab.”
Mackler has received one of Clark's new Steinbrecher Fellowships to help fund his research, as well as this year's M. Margaret Comer Memorial Award for Undergraduate Research in the Biological Sciences. He plans to continue with this project for his senior honors thesis in biology.
Science and service Mackler has known for some time that he wants to pursue a career in dentistry. While in London, he was able to observe how the alternative bone graft research might be applied in a dental context.
“Since Dr. Di Silvio's lab is in a hospital, I got to spend some free afternoons observing real dental procedures. I went to a cleft palate clinic, where I could see the problems that occur when the mouth does not form correctly during development in the womb. Those were the real-life applications of bone grafts.”
For Mackler, dental practice would satisfy a need to be of service to others. “I've always been interested both in science and in helping people through community service. Dentistry combines the two for me and bridges the gap between these two career paths. Practicing dentistry will allow me to interact with people directly and create long-term relationships, while still benefiting my own patients and healthcare. Of course, I would like to continue pursuing avenues of research throughout my career.”
Watching research unfold This summer, in Lyerla's lab at Clark, Mackler and the Summer Science students were able to witness the transformation of stem cells into osteoblasts, or bone cells. This was the first step in the tissue engineering process. Mackler describes the event, which happened on a Monday during the last week of the Summer Science Program.
“We all saw the stem cells turn into bone cells. We tested whether the treated cells produced a protein that only bone cells produce—the protein that initiates the formation of bone. When we added the differentiation ‘cocktail' to our Petri dishes, the experimental cells turned dark blue, while the untreated cells stained very lightly. Since this was the first time this experiment was performed in our own lab, we had had no idea if it would actually work. The students were here as it happened.”
Kao summed up the impact of being part of this event. “I've always heard a lot about stem cells and their ‘magic,' but actually seeing it happen was like finding out Santa Claus is real.”
The thousands of people requiring bone grafts each year would undoubtedly agree.
Read more about Harrison Mackler and check out his online diary at www.clarku.edu/activelearning/ departments/steinbrecherfellows/2006/ macklerdiary.cfm
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Clarknews Fall 2006
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Harrison Mackler '07 |
Harrison Mackler '07 |
Harrison Mackler '07 |
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