Production of highly porous triphasic calcium phosphate scaffolds with excellent in vitro bioactivity using vacuum-assisted foaming of ceramic suspension (VFC) technique

Abstract

We produced highly porous triphasic calcium phosphate (CaP) scaffolds, comprising of hydroxyapatite (HA), beta-tricalcium phosphate (beta-TCP), and alpha-TCP phases, using vacuum-assisted foaming of a ceramic suspension (VFC) technique. In particular, vigorously foamed CaP green bodies with a composition of similar to 60 wt% HA and 40 wt% beta-TCP were sintered at relatively high temperatures (1200, 1250, 1300, and 1350 degrees C) to control the amount of three constituent phases. All the produced samples showed a highly porous structure (porosity similar to 83.5-84.5 vol%, pore size similar to 312-338 mu m, and interconnection size similar to 61-74 mu m) with a number of microchannels in the CaP walls. However, sintering at relatively high temperatures >= 1250 degrees C induced considerable phase transformation of the beta-TCP to alpha-TCP phases. The presence of the more soluble alpha-TCP phase in the triphasic CaP scaffolds significantly enhanced the in vitro bioactivity of the porous CaP scaffolds, which was assessed in terms of their apatite-forming ability in simulated body fluid (SBF). (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.