A multi-scale porous scaffold fabricated by a combined additive manufacturing and chemical etching process for bone tissue engineering

It is critical to develop a fabrication technology for precisely controlling an interconnected porous structure of scaffolds to mimic the native bone microenvironment. In this work, a novel combined process of additive manufacturing (AM) and chemical etching was developed to fabricate graphene oxide/poly(L-lactic acid) (GO/PLLA) scaffolds with multiscale porous structure. Specially, AM was used to fabricate an interconnected porous network with pore sizes of hundreds of microns. And the chemical etching in sodium hydroxide solution constructed pores with several microns or even smaller on scaffolds surface. The degradation period of the scaffolds was adjustable via controlling the size and quantity of pores. Moreover, the scaffolds exhibited surprising bioactivity after chemical etching, which was ascribed to the formed polar groups on scaffolds surfaces. Furthermore, GO improved the mechanical strength of the scaffolds.