Fabrication and preliminary biological evaluation of a highly porous biphasic calcium phosphate scaffold with nano-hydroxyapatite surface coating

Abstract

Considering that the structure of scaffold determines its functionality, in this study biphasic calcium phosphate (BCP) scaffold with highly interconnected macroporous structure was firstly fabricated by a polymeric sponge replication method, in which a ethanol solution (25vol%) was use for preparation of the slurry and a varying slurry viscosity during multiple impregnations was adopted. Then, the surface coating consisting of nano-hydroxyapatite (nHA) particles was formed by a dip coating technology, i.e. immersing the porous scaffold into the nHA slurry (20mg/mL) and sintering it at 650°C. Preliminary in vitro experiments showed that compared to BCP one, nHA-coated BCP scaffold could increase protein adsorption, form more complex bone-like apatite, and promote cell adhesion and proliferation, indicating that nHA-coated BCP scaffold exhibited superior biocompatibility and bioactivity. It might be attributed to its surface nanostructure and abundant nano- to micro- scale pores (< 10µm). This nHA-coated BCP scaffold with both trabecular framework and surface nanoscale topography holds great promise in serving as bone graft for the orthopedic application.