Figure 4.

(A) Porogens such as salt or sugar can be distributed in a scaffold by size and subsequently leached out to create a porosity gradient. This construct can model the porosity gradient in bone. Porogen is denoted as yellow spheres, while resulting pores are white with imperfect boundaries. (B) Sugar particles leached out of a PLLA scaffold created a gradient in pore size from 300 to 600 μm. Sugar particle gradient can be seen in part a, with the resultant porosity after leaching in part b. Parts c-f are higher magnification. Reprinted from Reference 114 with permission from Elsevier.