3D printing of piezoelectric barium titanate/ hydroxyapatite composite ceramics for bone tissue engineeringTuesday (18.06.2019) 17:45 - 18:00
Piezoelectric ceramics are widely used in today's industry and in various applications known from daily life. The transfer of these ceramics into medical applications, such as electrically active implants with the potential of enhanced tissue regeneration, seems to be highly desirable. This study has considered a customized 3D printing process to fabricate piezoelectric, biocompatible ceramics for bone tissue engineering. Here we report the successful 3D printing of barium titanate (BaTiO3), a lead-free, biocompatible, ferro- and piezoelectric ceramic. For the printing process, a powder-based approach was applied, using a composite material mixture of BaTiO3, polyethylmethacrylat and hydroxyapatite. Via binder jetting 3D printing, the selective bonding of the particulate material was achieved. Cylindrical interconnected porous scaffolds with an average pore diameter of 1 mm were fabricated. Subsequent, the scaffolds were thermally debinded to remove the remaining organic residuals. The debinding was followed by a sintering process to increase the density and the mechanical integrity of the scaffolds. Afterwards, the scaffolds were characterised in terms of geometrical accuracy, porosity and mechanical integrity by compression testing. In vitro biocompatibility of the 3D printed scaffolds was tested in accordance to ISO19093-5, by growing cells in the eluate and directly, by seeding cells on the scaffold surface. Viability of the cells was assessed via different live/dead and proliferation assays. Furthermore the scaffolds were polarised in a strong electrical field to achieve piezoelectric properties. In terms of the piezoelectric constant d33 up to 32 pC/N could be achieved. The results represent the first milestone for the fabrication of piezoelectric barium titanate scaffolds for bone tissue engineering via 3D printing.