One of the first career decisions Ralph Müller had to make after receiving his master’s degree in electrical engineering was whether to enter the movie industry or the medical field. He opted for the latter, developing imaging techniques to diagnose osteoporosis during his Ph.D. and then learning about clinical, biomechanical, and biological aspects of orthopedics during a postdoc at Harvard Medical School in Boston.
Müller's diverse training prepared him to enter the field of biomaterials science, and today he directs the Department of Health Sciences and Technology’s Institute for Biomechanics  at the Swiss Federal Institute of Technology (ETH) Zurich, leading a multidisciplinary laboratory  that studies the structure and mechanical behavior of natural and engineered tissues.
As biomaterials science has matured, it has taken on much more biological content, moving from an approach that emphasizes inertness to one that embraces biological activity. Biomaterials science is “a growing field. It’s an exciting field,” says Nicholas Peppas, who chairs the Department of Biomedical Engineering  and leads the Laboratory of Biomaterials, Drug Delivery, Bionanotechnology and Molecular Recognition  at the University of Texas, Austin. It is also a very challenging field, demanding increasingly broad—but also deep—training and an ever more interdisciplinary approach. “This kind of working together in these interdisciplinary groups is not always easy, and asks you to adapt,” Müller says.
Biomaterials are materials designed to be used in close contact with biological systems, tissues, and fluids and to serve a medical purpose—replacing a damaged organ, say, or treating a disease. Biomaterials are in wide use, including for titanium hip implants, microcapsules for drug delivery, and engineered skin.
But the characteristics of biomaterials have evolved over the field’s 50-plus years of existence. In the early days, biomaterials were expected to be inert, or at least biocompatible, to disturb the body as little as possible. The field has since shifted toward developing materials that interact with biological systems in a purposeful way. For example, researchers are developing “smart" biomaterials such as temperature-sensing hydrogels that can respond biologically to environmental conditions by changing their biomechanical or drug-releasing properties, says Seeram Ramakrishna, a professor of mechanical engineering and director of the Center for Nanofibers & Nanotechnology  at the National University of Singapore.
Perhaps the field's biggest revolution was the introduction of stem cells, which ushered in the era of tissue engineering and regenerative medicine. A great deal of research is now going into developing scaffolds that can be used in vitro or in vivo to support and direct the growth of stem cells into differentiated cells, so they can restore a malfunctioning organ or injured tissue. Ramakrishna, for example, is engineering nanofibers for a physical structure with the right chemical, biological, and electrical cues to regenerate heart tissues.
The way that research is done has also been changing, with implications for those who wish to enter the field. As researchers have been pushing for biomaterials with greater activity and similarity to biological systems, they’ve had to work increasingly across disciplines. “This means, effectively, that scientists working in the biomaterials field have to have a good chemistry background, perhaps a good physics background, definitely good biochemistry and biology, and a good appreciation, of course, of materials science,” Peppas says.
The hardest part is bringing all of this together in vivo. “That is really the greatest challenge, because many scientists can come up with new materials for certain applications, … but if they don’t know how these materials are going to be placed in the body and interact with the cells, interact with biological fluids and so on, they have no appreciation of the total problem,” Peppas says.
At the end of the chain are doctors and their patients, Müller says—so those seeking to enter the field can benefit from putting themselves in the position of clinicians as they try to solve patients’ problems.
Because of the field's impressive breadth, the routes in are almost limitless. You can enter from materials science, chemical engineering, chemistry, physics, mechanical engineering, electrical engineering, biology, biotechnology, medicine, pharmacy—even mathematics and computer modeling.
The difficulty is that you need expertise in several of those disciplines, and learning that much science is hard. Biomaterials scientists have traditionally gained their multidisciplinary training by getting a first degree, a Ph.D., and a postdoc, each in a different field. Another increasingly common approach is to enter an integrated biomaterials program—but because such programs tend to cover a little bit of everything, there is a danger of superficiality. If scientists “start too early to specialize in biomaterials, there is a risk that they … would know all the possible applications but they will maybe not have the basis to be able to develop new ideas or new systems,” says Christine Dupont-Gillain, who leads the Nanostructured Surfaces for Cell Engineering group at the Institute of Condensed Matter and Nanosciences  of the Université Catholique de Louvain in Belgium.
Whichever approach you take, you should strive to excel in a specific area, Müller says. “So if you came from engineering to this problem and we’re working at these interfaces of biology, medicine, and so forth, it’s best to stay on the engineering side … rather than to … start way below and go all the way up on biology or medicine.”
It is important to work in groups that are already active in the field of biomaterials science, Dupont-Gillain says. So make sure to choose a lab that is truly multidisciplinary or at least has some connections with other disciplines, the clinical environment, or people developing biomedical devices, she adds. Also look at the institution's broader scientific environment, because “you can benefit from help even from people that are not with the label ‘biomaterials,’ ” says Dupont-Gillain, who, as a bioengineer and physical chemist, collaborates with colleagues in surface science and cell biologists to develop biomimetic surfaces that can trigger desired cell behaviors.
Undergraduates interested in a biomaterials career should consider “spending a summer doing a medical internship, or spending some time in … a research and development environment of a company or in a government institute,” Peppas says. This will help to acquaint them with the field's objectives and demands. “The more experience they get early, … the better it will be for their future employment and for their future success.”
Not all the skills required in this field are scientific. One key trait of successful biomaterials scientists is an ability to span scientific cultures and speak a variety of scientific languages. It can be humbling. “You think you’re an expert and you don’t even know the very simple things and you have to ask all the time,” Müller says. “This is something that you have to overcome.”
You also need to be able to work in teams. “If you believe you are the only one that can bring the solution, I don’t think you will find anything, so you need to be very open-minded, have good communication abilities. … To gather people together is very important,” Dupont-Gillain says.
An understanding of research ethics is very important in biomaterials. Early-career scientists should take a course on medical ethics to gain an early appreciation of “some of the formidable difficulties in the biomaterials field,” Peppas says. Medical ethics covers the appropriate use of biomaterials in patients and for certain applications, but it also can help you deal with difficult situations, such as when you discover that a particular biomaterial you've spent several years developing "has some toxicity, or some adverse reaction with the tissue or with the body. One needs to be appreciative immediately of the fact that this has to be disclosed.”
It's important to maintain an awareness of the broader context of the research. The biomaterials field is different from medical engineering in that its devices are meant for use inside the body, so regulations are stringent and legal issues are considerable, Müller says. Cost is also a factor. “When we develop new biomaterials, we have to appreciate that … we have to come up with solutions that are cost-effective,” Peppas says. Some biomaterials scientists even have formal business education, like a master's degree in business administration.
Peppas believes that the "explosion in the field” brought about by the emergence of tissue engineering and regenerative medicine means increasing opportunities for young scientists. Currently, the majority of biomaterials jobs are in academia, but the private sector is showing signs of activity, with academic labs spinning out companies, pharmaceutical companies allying themselves to biomaterials companies, and traditional medical implant companies looking to replace their 50-year-old technology, Müller adds.
But Peppas expects the field's expansion to be limited eventually by constraints on healthcare costs. And Ramakrishna points out that rising enrollments in biomaterials training programs are already making the job search difficult, especially in industry. “The numbers of graduates that are coming out are enormous around the world. Now, all of them cannot find jobs in the same area,” Ramakrishna says.
Choosing a career in biomaterials is “risky, but you could be a part of something amazing,” Müller says. Beyond the excitement of working in a multidisciplinary and challenging field, biomaterials science offers the sense that your work is likely to directly benefit human health. “The biggest satisfaction of a scientist working in biomaterials, whether he is in the academic environment or … a government institute or in industry, is to see these materials used in patients," Peppas says.
The Society For Biomaterials  in the United States
The European Society for Biomaterials 
Biomaterials Science, 3rd Edition: An Introduction to Materials in Medicine , a book by Buddy D. Ratner, Allan S. Hoffman, Frederick J. Schoen, and Jack E. Lemons
Biomaterials: A Nano Approach , a book by Seeram Ramakrishna, Murugan Ramalingam, T. S. Sampath Kumar, and Winston O. Soboyejo
A presentation on “Biomaterials and How They Will Change Our Lives”  by Robert Langer of the Massachusetts Institute of Technology in Cambridge. Langer also gave a TED Talk on “Biomaterials for the 21st Century .”
A presentation on “Biomaterials for Tissue Engineering”  by Antonios Mikos of Rice University in Houston, Texas
A course on the “Structural Aspects of Biomaterials”  by Professor Lisa Pruitt at the University of California, Berkeley
*Top Image: Adapted with permission from Elaboration of Nanostructured Biointerfaces with Tunable Degree of Coverage by Protein Nanotubes Using Electrophoretic Deposition
Deepak M. Kalaskar, Claude Poleunis, Christine Dupont-Gillain, and Sophie Demoustier-Champagne Biomacromolecules, 2011, 12 (11), pp 4104–4111.
Copyright 2011 American Chemical Society.