Micro-Scale, Multi-Spectral Flourescent Imaging for Bio-Heat Transfer Applications

Michigan State University, East Lansing MI

Investigators

Abstract

0101161 McGrath Living biomaterials spanning the size scale from cells and tissues to entire organs can be damaged by accidental exposure to temperature extremes (e.g. frostbite and burns). Unusually high or low temperatures can also be used clinically to kill tumors by heating or freezing respectively. In contrast, proper use of low temperature exposure can be used to preserve cells and tissues for virtually indefinite periods. Furthermore, between the extremes of preserving and killing there are many surgical and biotechnology procedures that amount to producing biomaterials with modified characteristics by using heating or cooling (freezing). Examples include heating treatments for stabilizing joints, relieving spinal pain, cosmetic surgery and heart disease. In all of these cases it is very important to understand how the biomaterial responds to the temperature changes and associated events such as the phase changes which occur during freezing. Unfortunately, very often not enough is known about the detailed responses of cells, tissues and organs to temperature excursions. Furthermore, the experimental tools available to study the detailed responses are limited or lacking. We have identified two specific needs that are the focus of the proposed research. Current methods often use temperature-measuring devices that disturb the system measured (invasive), only measure at one location and are too large relative to the small sizes of interest. Thus the first need addressed by the proposed research will be to provide a means of continuously measuring temperature non-invasively (using optical methods) over entire surfaces of biomaterials (rather than single locations) with micro-scale spatial resolution. The current state of the art is also limited with regard to methods to measure whether cells within tissues are alive or dead. Thus the second need addressed by the proposed research will be to provide a means of continuously measuring tissue cell viability non-invasively (using optical methods) within tissues with micro-scale spatial resolution. Molecular biology methods are applied to accomplish this using tumor cells as an example. These two optical methods provide a means of directly linking the applied thermal history of the biomaterial to the biological response in a manner not possible previously. Examples of the successful implementation of these two methods will be developed as part of the proposed research. The successful completion of this research will provide tools that can be used to develop a better understanding of the response of many types of biomaterials to a variety of applied thermal challenges. This will form the basis of future methods of rationale design of thermal treatments for improved health care.