Characterization of morphology—3D and porous structure

In the biomedical field, a growing interest is focusing on 3D porous structures for different applications, in particular as scaffolds for tissue engineering. The morphology characterization of complex structures is a demanding but fundamental task, as the morphological properties, such as porosity, pore size, pore wall size, and interconnectivity, affect the mechanical behavior as well as the biological performances of the scaffolds. In this perspective, several techniques are available to assess and quantify the microstructure. Some methods, such as microscopy observation, allow only a qualitative evaluation of morphological features, others (i.e., gas pycnometry, mercury porosimetry, flow porosimetry) quantify only partially the microstructure. The development of micro-CT allowed the researchers to have a quantitative method to assess all the fundamental morphological parameters, necessary to obtain a complete characterization of complex 3D porous structures. In this chapter some techniques (microscopy observation, density measurements, gas pycnometry, mercury porosimetry, flow porosimetry, micro-CT) used for the morphological characterization of scaffolds are described, focusing on their working principles, achievable parameters, advantages and disadvantages, and possible applications; examples from scientific literature of the use of these techniques are proposed as well.