Tissue Engineering Technique
Student Looks for Cell Damage in the Use of Hydrogels
to Repair Injured Cartilage
In a Johns Hopkins tissue engineering lab where
researchers are making new materials to repair injured
knees, noses and other body parts, an undergraduate is
performing critical experiments to determine whether this
promising technique might damage cells.
Athar Malik, a senior biomedical engineering major from Novi, Mich., is conducting a study to determine if DNA in cells can be harmed by a chemical reaction that occurs during the tissue engineering process. His experiments in the laboratory of Jennifer Elisseeff, an assistant professor of biomedical engineering, have been supported by a Provost's Undergraduate Research Award from the university.
Elisseeff has been guiding efforts to repair injured cartilage and bone without major surgery by injecting a liquid filled with cells that should promote the growth of healthy new tissue. When a special light is shone on it, this liquid hardens into a gel that holds the therapeutic cells in place. But before this material, called a photopolymerizable hydrogel, is used in humans, Elisseeff wants to be sure the chemical reaction used to harden the liquid is not damaging the helpful cells being injected into the body. "Our studies so far lead us to believe that the process is safe," Elisseeff said. "But we want to be as certain as possible. If we do find cell damage and can figure out how it occurs, we can try to correct the problems before moving forward."
To look for signs of DNA damage to the treatment cells, Elisseeff turned to Malik, who has worked in her lab since his freshman year. He has contributed to the ongoing hydrogel research, receiving credit on three peer- reviewed journal papers, including one in which he was listed as a lead author. In a letter of support for Malik's undergraduate research grant, Elisseeff cited his rapid progress in learning laboratory techniques, along with his "outstanding work ethic, dedication and intelligence."
Malik said he had never taken part in formal lab research before arriving at Johns Hopkins. "One of the main reasons I joined this lab was to begin applying some of the things I'd learned in high school and in my classes here," he said.
For his current research project, Malik fills the chambers of a multi-well plate with a nutrient solution, then adds some of the adult goat stem cells that are being used in Elisseeff's injury repair project. After the cells have had time to thrive, Malik adds a photoinitiator, the chemical used to trigger the chemical reaction that hardens a hydrogel. He next exposes the wells to ultraviolet light for varying periods, setting off the chemical reaction.
"Our goal is to see if this reaction has damaged the cells," Malik said.
To find out, he extracts DNA strands from the cells and uses a lab test to determine their length. Shorter strands indicate they have been cut, a sign of damage. "If we see that the DNA has been damaged, we try to look at it in further detail to find out specifically what has caused the damage and what can be done to prevent it," Malik said.
After finishing his analysis of the data, the undergraduate hopes to publish his findings in yet another peer-reviewed journal article. "I feel very fortunate to have had the opportunity to work and have an active role in Professor Elisseeff's lab," Malik said. "When I first joined, she paired me with older members of the lab, so that I could learn from their experience. Now, I'm helping some of the younger students."
Outside the lab, Malik leads a busy life on campus. He serves as president of Tau Beta Pi, the engineering honor society, and works as a residence hall advisor. Last year, he received an honorable mention in USA Today's All-USA Academic Team program. After graduation in May, he hopes to enter a rigorous M.D.-Ph.D. graduate program. "I would like to both practice medicine and conduct biomedical research," he said.
On March 10, Steven Knapp, university provost and senior vice president for academic affairs, hosted the 12th annual Provost's Undergraduate Research Awards ceremony, which honored the 45 winners who conducted their projects in the summer and fall of 2004. Since 1993, about 40 students each year have received PURA grants of up to $3,000 to conduct original research, some results of which have been published in professional journals. The awards, funded through a donation from the Hodson Trust, are an important part of the university's commitment to research opportunities for undergraduates.
The Johns Hopkins University is recognized as the country's first graduate research university, and has been in recent years the leader among the nation's research universities in winning federal research and development grants. The opportunity to be involved in important research is one of the distinguishing characteristics of an undergraduate education at Johns Hopkins.
The Provost's Undergraduate Research Awards program provides one of these research opportunities, open to students in each of the university's four schools with full-time undergraduates: the Krieger School of Arts and Sciences, the Whiting School of Engineering, the Peabody Conservatory and the School of Nursing.
Color photos of the researchers available; contact Phil Sneiderman.
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