Isothermal Microcalorimetry: A Versatile New Tool for Biomaterials Research

U 2 -15 2 -30 E ;i 4 5 = 2 do--7s -Introduction. Some of the earliest scientific measurements were of heat produced or absorbed during physical changes of state and chemical reactions, including metabolic activity. Crude calorimeters for this purpose were among the earliest scientific instruments. For example, Bunsen (181 1-1899) placed smdl animals on blocks of ice, and used differences in the amount of melt water produced as a measure of relative metabolic activity. Calorimetry has, of course, progressed steadily. However, not many biomaterials scientists are aware of the sensitivity and power of isothermal microcalorimetry (IMC) as a tool for detecting either the rate of material degradation processes or the magnitude of cellular metabolic responses to materials, nor is there awareness of the predictive power of such data. This paper presents the principles of JMC and the results of some initial studies.