The crystallization behavior of porous poly(lactic acid) prepared by modified solvent casting/particulate leaching technique for potential use of tissue engineering scaffold

• We modified the typical solvent casting/particulate leaching technique in preparing the porous scaffold by employing the stable salt stack and diffusing the PLA solution into it.
• We have (1) investigated the crystallization behavior of PLA confined in limited space; (2) developed an available crystallinity control option in porous PLA scaffold preparation.
• The porous PLA foams have a lower crystallizability than the bulk materials.
• The macro-structure of pores of around 250 μm are obtained and the morphological effect of the heating process is obvious.

The porous poly(lactic acid) (PLA) foams potential for tissue engineering usage are prepared by a modified solvent casting/particulate leaching method with different crystallinity. Since in typical method the porogens are dispersed in the solution and flow with the polymers during the casting and the crystallinity behavior of PLA chains in the limited space cannot be tracked, in this work the processing is modified by diffusing the PLA solution into a steady salt stack. With a thermal treatment before leaching while maintaining the stable structure of the porogens stack, the crystallinity of porous foams is made possible to control. The characterizations indicate that the porous PLA foams have a lower crystallizability than the bulk materials. Pores and caves of around 250 μm size are obtained in samples with different crystallinity. The macro-structures are not much impaired by the crystallization nevertheless the morphological effect of the heating process is still obvious.