Guillermo Ameer (pictured left), an assistant professor of biomedical engineering at Northwestern University in Evanston, Illinois, has spearheaded an effort to develop biomaterials designed to replace damaged cardiovascular and orthopedic tissues. However, his important contribution almost didn't happen. One year before the United States invaded Ameer's native Panama to depose dictator and former CIA informant General Manuel Noriega, he escaped to live with his sister in New York City. He later moved to Texas with another of his sisters to study engineering at a community college and then transferred to the University of Texas, Austin (UT Austin), where he majored in chemical engineering. Although he faced the turbulence of political unrest as a young man, Ameer rose above those challenges and followed his dream.

From Chemical to Biomedical Engineering

Ameer will be the first to admit that he did not do it alone. Despite his then-immigrant status (he is now a U.S. citizen) and community college background, he was able to secure relevant internships and establish a solid network of mentors and peers. He had internships at Hoechst Celanese and Shell Oil in conventional chemical engineering projects, but it was a research project at his second Hoechst Celanese internship that sparked his interest in pursuing graduate research. That interest was further developed into biomedical engineering after taking a course at UT Austin with Robert Popovich, co-inventor of continuous ambulatory peritoneal dialysis.

As a graduate student at the Massachusetts Institute of Technology (MIT), Ameer studied with biotech pioneer Robert Langer, who created a technique to control drug release with specially developed plastics. With the help of UT Austin faculty members and contacts he made at a National Society of Black Engineers meeting, he earned his Sc.D. in chemical engineering. He then completed a joint postdoctoral fellowship under Hidde Ploegh, director of the Department of Pathology at Harvard University, and William Harmon, chief of nephrology at the Harvard-affiliated Children's Hospital in Boston.

All-Natural Solutions

Ameer's lab has received acclaim for developing a cross-linked elastomer (which has been called biorubber) to replace the synthetic materials that are currently used in tissue substitutions. Many of his projects are collaborations with medical personnel. For example, he works with William Pearce, chief of vascular surgery at Northwestern's Feinberg School of Medicine, on cardiovascular tissue engineering and with Bobby Satcher, orthopedic surgeon, on ligament tissue engineering. He is also considering reconstructive surgery applications. Currently used polyurethanes are permanent, tend to clot, and may be carcinogenic; therefore, Ameer's biorubber is in demand. It is designed to mimic human tissue and has four advantages not seen in polyurethanes:

  • It is composed of materials naturally found in the body and found to be relatively nontoxic.

  • It stretches and recoils to its original length, similar to rubber.

  • It is biodegradable, which facilitates the regeneration of natural, functional tissue.

  • Its load and strain capacities are similar to those of natural tissue.

  • On an additional project with former MIT graduate student Eric Grovender, Ameer co-developed a cartridge filter that purifies blood, "based on protein and cell engineering," for those suffering from chronic kidney failure. Ameer's lab is now developing an improved second-generation biomaterial with greater strength, degradation control, and macromolecular regulation. The materials used are different from the first generation and are "very benign," according to Ameer. This work was recently accepted for publication in the renowned international journal, Advanced Materials. Ameer's group is also considering seeding the implanted biomaterial with regenerative cells according to an article in the Chicago Sun-Times . Collaborations with Northwestern Professor of Biomedical Engineering Vadim Backman will yield "minimally invasive, quantitative, and real-time techniques to assess microarchitecture and function of the scaffolds in bioengineered tissue." (See the Ameer laboratory Web site.)

    Awards

    Guillermo Ameer has been the recipient of many awards, including selection as one of "The 100 Bold Young Innovators You Need to Know" in the October 2003 edition of Technology Review magazine. The following three awards are from the Northwestern University McCormick School of Engineering and Applied Science Faculty Honors from August 2001 to August 2002.

  • Ameer's team won first and third places, as well as honorable mention, in the first Margaret and Muir Frey Memorial contest for various biomedical engineering projects.

  • Ameer was the recipient of the National Kidney Foundation's Victor M. G. Chaltiel Young Investigator grant and the American Heart Association's Scientist Development grant.

  • Ameer served as the principal investigator for the team that received an Institute of Bioengineering Nanoscience and Medicine seed grant.

  • For the Love of Science and Teaching

    When he transitioned from postdoc to professor, 2 ½ years ago, he found himself responsible for the entire lab, not just himself and a few graduate students. Since then, the Ameer lab has mushroomed from one person last year to two postdocs, six graduate students, five undergraduates, a research associate, and a personal assistant from various disciplines, races, and nationalities. Ameer says, "Being a professor is like having your own business. The only difference is that we're not independently wealthy. The biggest challenge is trying to relay your vision to graduate students, postdocs, as well as peers. You must excite other people so that they're on the same page as you are in order to get the outcome you would like."

    Despite the difficulties involved in an academic career such as raising funds, dealing with people, and managing employees, Ameer finds the rewards to be much greater. He enjoys his daily interaction with others also interested in bioengineering and other sciences and the "one-to-one interaction" involved in teaching students. He especially enjoys the freedom granted to set one's agenda as well as one's own style of working. However, because of his busy schedule he admits, "I'm not in the lab as much as I would like to be."

    Insights into Success

    At age 33, Ameer has had a remarkable amount of success. He humbly attributes his success to hard work, luck, and support from his family and friends. "I've had a lot of people supporting me. If you have someone who's there for you when things aren't going that great, it helps you move on. It's very easy to get disappointed. It's a lot more difficult for you after setbacks to just pick up and go again, and there's a lot of that in academia."

    He feels that sometimes minority students get a similar "mind block" that limits their thinking to "How are they going to treat me?" instead of "How am I going to affect other people?" or "What contributions will I make?" He notes that there are not enough minorities at the Ph.D. level in biomedical engineering. "I think it's a great field to enter at this time because bioengineering continues to attract talented, enthusiastic professors and have new discoveries in biology and chemistry." Ultimately, Ameer says, "you have to pursue what is important to you. You have to put your heart and mind into it."

    Clinton Parks is a writer for MiSciNet and may be reached at cparks@aaas.org.

    Clinton Parks is a writer for MiSciNet and may be reached at cparks@aaas.org.