Seminars

Joint ME/IE 8773-8774 Seminar

Micro and Nanoscale Phenomenon in Bioheat Transfer

by

John C. Bischof
Professor in Mechanical Engineering,
Biomedical Engineering, and Urologic Surgery
University of Minnesota

September 22, Wednesday, 3:30-5:00 pm
1130 Mechanical Engineering
Coffee and Cookies will be available before and following the lecture

Abstract:

Bioheat transfer plays a crucial role in many biomedical applications in cryobiology (cryopreservation and cryosurgery) and hyperthermic biology (thermal therapies and burn injury) where thermal excursions can be used to either preserve or destroy viability in a biological system. In this talk I will review work focusing on micro and nanoscale phenomenon, which are important in defining outcomes of both cryobiological and hyperthermic biomedical applications. Initially the thermal properties of the biological system itself need to be understood so that temperature, and thus the heat transfer process, can be measured and predicted. In the case of cryobiological applications, these properties can depend dramatically on temperature and at the micro and nanoscale will vary with crystallization, vitrification or eutectic phases present. In the case of hyperthermic applications, these properties are also temperature dependent (although less so), and they can be altered by the presence of magnetic nanobeads which enhance local power deposition and are currently being evaluated for targeted drug delivery, biomolecular tagging and as MR contrast agents. During the actual bioheat transfer protocol, there are further thermophysical microscale phenomenon, which depend on the heat transfer process such as cellular dehydration, intracellular ice formation, membrane blebbing and hyperpermeability, which are mechanistically linked to viability outcomes. Molecular and nanoscale phenomenon include lipid segregation and phase change, and protein denaturation as well as gene regulated events (inflammation and apoptosis), which have also been linked to viability outcomes. These events have also been shown to play critical roles in the mechanism of injury and therefore viability outcomes form bioheat transfer applications in biomedicine.

 

Bio: John C. Bischof earned a Bachelor of Bioengineering with honors from the University of California at Berkeley in 1987, followed by a Master of Science in the same field in 1989 from a joint program between the University of California at San Francisco Medical School and the University of California at Berkeley's College of Engineering. Subsequently, he was awarded the Doctor of Philosophy degree in Mechanical Engineering from the University of California at Berkeley in 1992. After spending a year as the John F. Burke Postdoctoral Fellow in Biomedical Science and Engineering in the Department of Surgery at Harvard Medical School, he came to the University of Minnesota in 1993 where he currently serves as a faculty member in Mechanical Engineering with joint appointments in Biomedical Engineering and Urologic Surgery. Professor Bischof is a recipient of a Whitaker Young Investigator Award, an NSF Research Initiation Award, and an NSF Career Award. He also held the title of McKnight Land Grant Assistant Professor at the University of Minnesota.

Informal Faculty Luncheon: Wednesday, September 22, 2004, 12:00 noon. Meet in 1100 ME and walk to lunch with other faculty. Prof. John Bischof will not be able to attend.