PORE STRAIN BEHAVIOR OF COLLAGEN-GLYCOSAMINOGLYCAN ANALOGS OF EXTRACELLULAR-MATRIX

Mechanical properties of a highly porous collagen-glycosaminoglycan (C G) analogue of extracellular matrix were investigated. The stress-stra in behaviour of the matrices displayed the typical concave-up shape ch aracteristic of porous materials and soft tissues. Deformation behavio ur of the material was further investigated using novel methodology to determine material strains at the micrometre level. Central to the me thodology was the use of scanning electron microscopy (SEM) in conjunc tion with a digital image analyser. The method for strain determinatio n at the micrometre level was verified by comparison with measurement of surface strain using an optical method. An unexpected finding in th ese materials is that Poisson's ratio varies with engineering strain. A geometrical/mathematical model was developed to explain this behavio ur. These results encourage further investigation of the mechanical pr operties of these materials, in order to provide important insights in to the physical microenvironment in which cells reside.