β-TCP/PVA sheets crosslinked with citric acid produced via aqueous tape casting for bone regeneration

Abstract In this study, β -TCP/PVA and β -TCP/PVA-R bioactive sheets were produced via tape casting. A crosslinking agent, citric acid, was used in order to improve the mechanical properties of the material. The viscosity of the slurries for both compositions were shown to be ideal for tape casting processing. As for the XRD analyses, peaks related to the β -TCP phase were found, however, processing without citric acid led to a greater structural disorder of the β -TCP phase, which is evidenced by the reduction of sorting zones within the crystals (crystallite). The water uptake evaluation showed that the crosslinked sample has a higher resistance when in a aqueous medium, and in addition, SEM images illustrated that the crosslinked sheet has a denser structure. The precipitates formed on the surface of the samples after 7-days of having been immersed in McCoy's 5A medium and this bioactivity analysis proved that the materials were bioactive. When comparing the two compositions, TCP/PVA and TCP/PVA-R, it was possible to see that the crosslinked sample presented a greater amount of precipitates.