Quantitative architectural description of tissue engineering scaffolds

Arguably one of the most specialised subtopics in porous materials research is that of tissue engineering scaffolds. The porous architecture of these scaffolds is a key variable in determining biological response. However, techniques for characterising these materials tend to vary widely in the literature. There is a need for a set of transferable and effective methods for architectural characterisation. In this review, four key areas of importance are addressed. First, the definition and interpretation of pore size are considered in relation to fluid transport properties, by analogy with filtration research. Second, the definition of interconnectivity is discussed using insight obtained from cement and concrete research. Third, the issue of data scalability is addressed by consideration of percolation theory, as implemented for the study of geological materials. Finally, emerging techniques such as confocal and multiphoton microscopy are discussed. These methods allow the three-dimensional observation of pore strut arrangement, as well holding great potential for understanding changes in pore architecture under dynamic conditions.