Buddy Ratner, Professor

Michael & Myrna Darland Endowed Chair in Technology Commercialization
Joint with Chemical Engineering
Director, University of Washington Engineered Biomaterials (UWEB)

Research Areas
Biomaterials & Tissue Bioengineering
Molecular Bioengineering

Education
PhD (polymer chemistry), Polytechnic Institute of Brooklyn, 1972

• Synthesis and characterization of polymeric biomaterials
• Surface analysis by ESCA, SIMS, STM, FTIR-ATR, AFM
• Plasma deposition of thin films
• Tissue Engineering
• Scaffolds

Contact Information
Department of Bioengineering
University of Washington
Box 355061
William H. Foege Building, Room N330J
Phone: 206-685-1005
Fax: 206-616-9763
E-mail: ratner@uweb.engr.washington.edu

Research Description
Medical devices and implants are engineered from specially designed materials, often referred to as biomaterials. Millions of devices and implants are used clinically in applications as diverse as blood vessel replacements, catheters, contact lenses, hip joints, ventricular assist devices and artificial kidneys. The biocompatibility of these prostheses is dictated by their surface properties and by the local mechanical environment they induce. In my research program, biomaterials are engineered to control biological interactions, synthesized, characterized and observed during interaction with biological systems.

Today's biomaterials and medical devices save lives and improve the quality of life for millions. These are part of a $100 billion industry. However, there are also complications that stem from these devices, often associated with non-physiologic (fibrotic) healing, initiation of inflammation, thrombosis and/or bacterials colonization. The University of Washington Engineered Biomaterials (UWEB) program (an NSF Engineering Research Center) asks if healing and performance of implanted biomaterials might be engineered to be similar to the healing of normal wounds? To do this, we study the basic biology of wound healing in collaboration with colleagues who are expert in these areas. Then, we, as engineers, translate the basic science discoveries into technologies appropriate to improve the performance of medical devices.

We engineer new biomaterial surfaces using a wide range of technologies. For example, radio-frequency plasma deposition (a method borrowed from microelectronics) can readily place interesting thin films on existing medical device surfaces. These films can be used in the precision immobilization of key signaling molecules. We also synthesize new polymers that can be biostable, environmentally responsive, biodegradable and/or porous (i.e., scaffolds). The new surfaces and materials made in our laboratory are studied in contact with proteins, blood, living cells and tissues (in vivo and in vitro).

Recently, there has been considerable interest in tissue engineering in my laboratory. Tissue engineering exploits all the above principles in the context of tissue and organ reconstruction and regeneration. Specific tissue engineering projects in the Ratner lab aim toward heart muscle, esophagus, bone, cartilage, bladder, vagina and cornea. A new project seeks to model cancer tumor microenvironments using tissue engineering ideas.

Biomaterials/biocompatibility projects ongoing in my laboratory include:

• drug delivery devices
• porous scaffolds
• tissue engineering
• angiogenesis
• healing in soft tissue
• bioelectrode performance
• bioattachment
• biorecognition
• polyurethanes
• hydrogels
• biodegradable polymers
• non-fouling surfaces
• blood-contacting materials
• bacterial biofilms/infection

Biomaterial surfaces are the only part of a biomaterial or medical device that is seen by the body. Surfaces present unique analytical problems because of the small mass of material involved (a billionth of a gram of matter per square centimeter is typical). Special instruments are required to study surfaces, and we adapt methods developed in the physics and microelectronics communities to problems in biology and medicine. We use electron spectroscopy for chemical analysis (ESCA), secondary ion mass spectrometry (SIMS), infrared spectroscopy, scanning probe microscopies, surface plasmon resonance and sum frequency generation to observe surface structure and biological interactions.

Selected Publications

• “A Paradigm Shift: Biomaterials that Heal,” B. Ratner, Polymer International, 56:1183–1185, 2007.
• “Investigation of the Foreign Body Response with an Implanted Biosensor by In Situ Application of Electrical Impedance Spectroscopy,” F.B. Karp, N.A. Bernotski, T.I. Valdes, K.F. Bohringer, B.D.Ratner, IEEE Sensors, 8(1):104–112, 2008.
• "Biomedical Surface Science: Foundations to Frontiers," D.G. Castner, B.D. Ratner, Surface Science 500, 28–60, 2002.
• "Development of an electrospray approach to deposit complex molecules on plasma modified surfaces," K.J. Kitching, H-N. Lee, W.T. Elam, E.E. Johnston, H. MacGregor, R.J. Miller, F. Turecek, and B.D. Ratner, Review of Scientific Instruments 74(11), 4832–4839, 2003.
• "Biomaterials: Where We Have Been and Where We Are Going," B.D. Ratner and S.J. Bryant, Annual Reviews of Biomedical Engineering, Vol. 6:41–75, 2004.
• "Novel cell patterning using microheater-controlled thermoresponsive plasma films," X. Cheng, Y. Wang, Y. Hanein, K.F. Bohringer, B.D. Ratner, Journal of Biomedical Materials Research, 70(A), Issue 2, 159–168, 2004.