Newell Washburn
Assistant Professor of Chemistry and Biomedical Engineering
Research Interests
Combining polymer/materials science and physical chemistry with biomedical engineering, Washburn develops therapies for tissue repair. He uses spectroscopic methods to study demineralized bone matrix, a biological material obtained from cadavers that is used to treat patients with damaged bone tissue. Characterizing demineralized bone matrix is key to creating a synthetic version that will mimic the biological one.
Professional Background
Ph.D. Chemistry, University of California (Berkeley), 1998
B.S. Chemistry, University of Illinois at Urbana-Champaign, 1993
After earning his doctorate from University of California, Berkeley, Washburn did postdoctoral research in the Department of Chemical Engineering and Materials Science at the University of Minnesota. In 2000, he joined the research staff of the National Institute of Standards and Technology and was the leader of the biomaterials group in the polymer division there. He was also an adjunct professor in the graduate program in biotechnology at Johns Hopkins University. He joined the Carnegie Mellon faculty in 2004.
Why are synthetic materials needed to treat damaged bone tissue?
There are many cases when patients’ fractures fail to heal. To encourage the damaged bone tissue to heal, many physicians are treating patients with demineralized bone matrix, which is obtained from human donors. Demineralized bone matrix is rich in proteins known as growth factors as well as proteins that regulate the activity of these growth factors. Growth factors signal bone cells in the area to multiply and begin specializing to form complex bone tissue. Demineralized bone matrix plays a critical role in regulating their activity by sequestering growth factors until they are needed. Understanding the interactions of growth factors with the matrix is crucial in designing synthetic equivalents, which are needed because demineralized bone matrix is in limited supply.
What methods do you use in developing a synthetic bone matrix?
Understanding the dynamic interactions of growth factors with demineralized bone matrix is key to creating a successful synthetic matrix. My research centers on performing physical measurements, including fluorescence correlation spectroscopy, to measure the dynamics of growth factors as they interact with the demineralized bone matrix. These studies are an important first step to help us develop a synthetic hydrogel with which growth factors will have similar interactions as they do with demineralized bone matrix. This novel biomimetic approach could lead to the development of synthetic matrices that have similar function as therapeutically effective matrices, such as demineralized bone matrix, without the risks associated with these biological materials.
How does fluorescence correlation spectroscopy work?
Fluorescence correlation spectroscopy is a technique I’m using to characterize how growth factors interact with demineralized bone matrix and with our synthetic matrix. We start by labeling a growth factor with a fluorescent tag and adding it to the matrix. We then shine a laser onto the matrix, causing the growth factor to glow, which allows us to follow its diffusion, binding and interaction with the matrix. Based on the data we gather from these studies, we can then design a synthetic material that behaves in the same was as demineralized bone matrix. We will carry out the same fluorescence correlation spectroscopic studies on our synthetic matrix.
What approaches are involved in your work on promoting the growth of new bone tissue?
Hydrogels are promising as the state-of the-art in tissue engineering design. They are made from polymers that swell in water to form a gel-like material that acts as a scaffold so that bone cells can proliferate and form new tissue. We’ll design our synthetic hydrogel to consist of a polymer matrix, several growth factors, and bone cells that will all interact with one another. Another aspect of my research involves looking at these many important variables at the same time to gain a global understanding of the cell-material interactions in the entire system, a technique known as combinatorial screening. We ultimately hope to create a hydrogel that will temporarily replace damaged bone tissue, actively guide regeneration, and degrade when new bone tissue has formed.
Are you collaborating with anyone here at Carnegie Mellon?
One of the reasons I was so pleased to join the faculty at Carnegie Mellon is the interdisciplinary and collaborative nature of research here. I’m working with Jeff Hollinger, director of the Bone Tissue Engineering Center, Krzystof Matyjaszewski, professor of chemistry and polymer expert, and Lynn Walker, associate professor of chemical engineering.
Amy Pavlak
January 10, 2005
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