Characterisation of Porous Calcium Phosphate Scaffolds for Bone Tissue Engineering

Methods: Porous calcium phosphate scaffolds (hydroxyapatite and biphasic calcium phosphate formed by combining hydroxyapatite with β-tricalcium phosphate) were fabricated by Ceramisys Ltd. and supplied as discs.  Hydroxyapatite (HA) & biphasic calcium phosphate (BCP) discs (n=9) were analysed by desktop microCT (μCT 40, Scanco Medical AG, Brüttisellen, Switzerland). Cultured osteoblast-like cells (ROS 17/2.8) were used to investigate biocompatibility at two seeding densitites.

Results:  HA & BCP discs were measured for porosity, average pore diameter, average structure thickness, pore interconnectivity, pore connectivity density and specific surface area. HA showed the greatest porosity (62%), specific surface area (7.3 mm2/mm3), average pore diameter (268 μm), & pore interconnectivity (99.5%). BCP showed the lowest porosity (54%), specific surface area (6.1 mm2/mm3), & pore interconnectivity (98.5%). There was no significant difference observed between cell growth on either scaffold, irrespective of seeding density.

Conclusion: The porous calcium phosphates evaluated in this study were well-suited to bone tissue engineering with an appropriate pore size and excellent interconnectivity.  The growth of culuted bone cells suggested that both materials would be very biocompatible at all stages of the tissue engineering process from pre-culture prior to clinical use.

Acknowledgments: The authors would like to acknowledge Ceramisys Ltd. for materials and for funding a CASE student with the EPSRC and the European Commission (Contract NOE-500283-2) for supporting collaboration between the UK and Switzerland.