Development of nano- and microscale composite 3D scaffolds using PPF/DEF-HA and micro-stereolithography

Although the merits of using nano/microscale composite structures to promote cell proliferation are well established, the fabrication of such scaffolds using conventional methods does not allow control of the shape of composite structures. In contrast, solid free-form fabrication (SFF) permits shape control, and among SFF technologies, micro-stereolithography (MSTL) has the highest resolution. Therefore, we used MSTL to fabricate a nano/microscale composite scaffold containing hydroxyapatite (HA) nanopowder. The photopolymer used for fabricating the scaffold, poly (propylene fumarate) (PPF), was synthesized via a condensation reaction of fumaric acid and propylene glycol. After synthesis, diethyl fumarate (DEF) was added to reduce the viscosity. Finally, the photoinitiator bis-acylphosphine oxide (BAPO) and 7% (w/w) HA were mixed with the synthesized photopolymer. Scaffolds containing nano/microscale structures using MSTL technology and PPF/DEF-HA photopolymer were fabricated successfully and the pores and line structures of the scaffolds were regular. Moreover, all of the pores were connected and the use of HA powder effectively generated nano/microscale morphology. In addition, MC3T3-E1 cells seeded on the PPF/DEF-HA scaffolds showed better cell adhesion and proliferation than on PPF/DEF scaffolds. Our results indicate that scaffolds containing HA powder may be applicable to bone tissue regeneration.