Design of Biomaterials: The Balancing Act between Reductionism and Systems Thinking

Abstract

I start with a story that demonstrates the importance of the above quote. As an undergraduate, I had great interest in biomaterials, and took a technical elective graduate course in biomedical engineering focused on rehabilitation engineering. We studied all sorts of electrical stimulation devices and controllers designed to trigger different muscle groups for various therapies—we even tested them on ourselves! In one case study, our professor told us that he and a team of engineers managed to design a control system and series of implantable electrodes in groups such that locomotion was restored for a quadriplegic patient—a fantastic achievement! Such a solution required knowledge of physiology, electrical engineering, biomedical engineering, computer process control, electronics, and surgery. However, despite such a wonderful achievement (allowing a paralyzed patient to walk again) the project was an utter failure. Why? Simply put, when the patient was asked to comment on what they thought about their restored ability to walk again the patient effectively said: ‘‘Walking is alright I guess, but really, I am used to the wheelchair now. I would much rather have bladder control than to walk again, but no one asked me.’’ The moral? Human factors play a huge role in the design of solutions, and we, as technical people, sometimes forget to ask important non-technical questions. The same is true in research of biomaterials—the big picture is just as important as all the little details. The painting in Fig. 1 by Georges Seurat illustrates that, like a research subject, a big picture is made of many tiny details (inset) with their own problems to solve. For example, the color and placement of each paint daub must be precise and uniform in size or texture, but when a single daub is then seen close to nearest neighbors, next nearest neighbors, and next–next nearest neighbors, etc., an image representative of something altogether different from a single paint daub is formed. The analogy to materials research is that with proper care to integrate the little details, a bigger picture or understanding may follow. The caution is to not get lost in details and to insure a process wherein such little details are purposely designed with the aim of seeing the big picture, or impact of the results. Perhaps this is an obvious analogy, but the analogy can be extended to ways of thinking as well: each paint daub is a detail as discovered by reductionist thinking, yet when all the daubs are integrated together, a beautiful scene blossoms, and forthwith, emotional and psychological responses are triggered based on the viewers’ association with the particular depiction of the world—hence a systems thinking approach, complete with human factors, is seen in the entirety of the impressionist painting. As we have tried to understand our world, two schools of thought, reductionist thinking and systems thinking, have evolved. Each has its merit and disadvantages, but in this commentary we explore each paradigm in relation to how biomaterials design and research is being carried out currently, and we propose some ideas for the future—we need a more present and effective balance between reductionism and systems thinking. John A. Nychka and Jamie J. Kruzic—guest editors for the Biomaterials Committee of the TMS Electronic, Magnetic, and Photonic Materials Division and the TMS Structural Materials Division—coordinated the topic BiologicalMaterials Science: Fundamentals in this issue. JOM