Confocal laser scanning microscopy (CLSM) for the study of collagen sponge microstructure.

This study uses confocal laser scanning microscopy (CLSM) to assess the microstructure of collagen sponges providing an accurate quantification of porosity under conditions similar to those experienced by cells growing on the sponges during culture. CLSM offers several advantages over scanning electron microscopy (SEM) and conventional optical microscopy for this kind of study, the most important of which is probably the absence of artifacts associated with the extensive preparation of samples required for the latter two methods. When the "pan-side" surface of collagen sponges was studied, it was found that the pore sizes increased with increasing depth into the sponge. Collagen sponges frozen in a -70 degrees C freezer had a more open structure than ones frozen on the stage of a tissue dryer. These different pore sizes are thought to reflect different freezing rates in the samples.