Influence of a novel calcium-phosphate coating on the mechanical properties of highly porous collagen scaffolds for bone repair

Lyophilised collagen scaffolds have shown enormous potential in tissue engineering in a number of areas due to their excellent biological performance. However, they are limited for use in bone tissue engineering due to poor mechanical properties. This paper discusses the development of a calcium-phosphate coating for collagen scaffolds in order to improve their mechanical properties for bone tissue engineering.Pure collagen scaffolds produced in a lyophilisation process were coated by immersing them in sodium ammonium hydrogen phosphate (NaNH4HPO4) followed by calcium chloride (CaCl2). The optimal immersing sequence, duration, as well as the optimal solution concentration which facilitated improved mechanical properties of the scaffolds was investigated. The influence of the coating on composition, structural and material properties was analysed.This investigation successfully developed a novel collagen/calcium-phosphate composite scaffold. An increase in the mechanical properties of the scaffolds from 0.3 kPa to up to 90 kPa was found relative to a pure collagen scaffold, while the porosity was maintained as high as 92%, indicating the potential of the scaffold for bone tissue engineering or as a bone graft substitute.