A MULTISAMPLE DENATURATION TEMPERATURE TESTER FOR COLLAGENOUS BIOMATERIALS

The temperature at which collagen denatures from a triple helix to a r andom coil structure is a useful measure of the degree of crosslinking . A new multi-sample denaturation temperature tester (DTT) has been co nstructed for rapid determination of tile collagen denaturation temper ature of natural tissues and collagenous biomaterials. To validate the system, the denaturation temperatures measured for the DTT are compar ed with results from differential scanning calorimetry (DSC). Data are presented for bovine pericardium in three states with denaturation te mperatures ranging from 68 to 85 degrees C: fresh, or crosslinked with glutaraldehyde or the epoxide reagent Denacol EX-512 poly (glycidyl e ther). Denaturation temperatures measured by DTT were not significantl y different from those measured by differential scanning calorimetry ( DSC); however, DSC onset systematically occurred at a slightly lower t emperature than that measured by DTT. This result, seen only for fresh tissue is in agreement with earlier experiments using hydrothermal is ometric tension (HIT) testing. By contrast, DTT and DSC onset were ide ntical for the exogenously crosslinked materials. Since tile measured transition temperature was independent of initial load, this variable may be chosen to yield sharper force-temperature transitions with a gi ven sample geometry. This instrument allows accurate assessment of col lagen denaturation temperatures for multiple samples in a fraction of the time required by other methods.