Measurement of the Pore Size and Porosity of Tissue Scaffolds

Tissue engineering involves seeding the patient’s cells on to a three-dimensional temporary scaffold. It is becoming increasingly obvious that cells used to seed the scaffold have very specific requirements concerning the morphology and chemistry of the surface of the scaffold and its interconnectivity. A range of techniques has been examined in relation to key measurements such as pore size and porosity. Since capillary flow porometry measures a pore solely at its most constricted point, the method is unable to provide characterisation of other aspects of the pore. Scanning Electron Microscopy is limited to examining surface pores in ‘stiff’ scaffolds. Although cryo-SEM reduces the amount of ice-induced damage generated in ‘soft’ scaffolds upon freezing, the technique is limited to the same constraints. Images produced via scanning confocal microscopy are probably more representative of the true structure of the scaffold than that implied by cryo-SEM, although due to the diffuse nature of the image it is difficult to measure pore sizes.