A novel foaming technique to develop functional open-cell polylactic acid scaffolds for bone tissue engineering

Abstract

The aim of this study was to develop a solvent-free polylactic acid (PLA) open-cell porous scaffold for bone tissue engineering using compression molding and a new chemical foaming compound, that we named CFCO. The latter is composed of a blend of PLA and azodicarbonamide (ADA) as a chemical foaming agent, with the addition of chitosan-grafted PLA (CS-g-PLA) copolymer at various concentrations. The novelty of this approach is that during the foaming, that is, during the decomposition of the ADA foaming agent, the CS-g-PLA copolymer is projected toward the surface of the pores and strongly adhere there, which was confirmed by scanning electron microscopy and confocal microscopy. The results showed that at 6.90 wt% of CS-g-PLA copolymer, the immobilization of the latter on the surface of the pores led to a 52% increase in cell proliferation compared to the pure PLA control sample and a 26% increase compared to scaffolds that had 10 wt% of CS-g-PLA copolymer dispersed throughout the entire PLA matrix.