PLA-based foams as scaffolds for tissue engineering applications

In this work a simple, innovative, low-cost methodology was developed to produce PLA-based foams with good physico-mechanical properties and well interconnected open-pores in absence of organic solvents and chemical foaming agents. At first biocomposites were prepared by melt-blending crosslinked particles of sodium polyacrylate, commonly used as superabsorbent polymer (SAP), and poly-L-lactic acid based matrices (PLA). Morphological analyses showed a biphasic system with a regular distribution of particles, with diameters up to about 50 µm, within the PLA based matrices. The mechanical properties of PLA based matrices, dependent on biomaterial compositions, are markedly modified by addition of crosslinked particles, revealing by a regular stiffening effect. In addition, the polymeric biphasic system showed excellent swelling properties, demonstrating that cross-linked particles retain their superabsorbent ability even if distributed in a thermoplastic polymeric matrix. Subsequently, in aqueous environments the particles swell and are leached from PLA based matrices generating very high porosity. The new open-pore biomaterials allowed good cell adhesion and proliferation during culture of rat myoblasts cell lines. Hence this procedure, in general applicable not only to PLA-based polymeric systems but also to other biocompatible polymers, is suitable to selectively modify biomaterial properties and appear very promising for several applications, in particular for scaffold production in tissue engineering.