Mechanical Properties and Biodegradation Behavior of 3D-Printed HA/β-TCP Composite Scaffold for Bone Tissue Engineering Applications

Objectives: Regeneration of bone by tissue engineering has attracted great attention because of its potential advantages over synthetic implants, the traditional method used for tissue replacement. This research aims to develop and evaluate beneficial porous composite scaffolds, since there is no current ideal or appropriate scaffold based on pourous biomaterials. Hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) composite scaffolds have shown significant potential for bone tissue engineering applications.
Methods: In this study, ceramic scaffolds with different HA/β-TCP compositions (pure β-TCP, 20HA/80β-TCP, 30HA/70β-TCP, and 50HA/50β-TCP) were fabricated by 3D printing technique using water-based paste. Thereafter, the prepared scaffolds sintered at 1100°C for 4h with a heating rate of 5°C/min. A systematic study was conducted to investigate the porosity, mechanical properties, and biodegradation of the scaffolds.
Results: In the fabrication procedure, HA/βTCP composite paste with noticeable consistency, stability and liquidity is produced by pondering the dominant factors such as its ingredients and viscosity. After optimizing the system parameters, scaffolds with homogeneous and interconnected pores with sizes ranging from 400 to 600 μm were acquired, and the entire procedure had great stability and reproducibility. The compressive strengths of the prepared scaffolds with hundreds of micrometers were equal to the range of human cancellous bone (2–12 MPa). For a given size of macro-pores, the biodegradation rate decreases as a function of the composition in the following order: βTCP> 20HA/80βTCP> 30HA/70βTCP> 50HA/50βTCP.
Conclusions: 3D printing technique could be utilized to develop a scaffold with customer-designed chemistry and architecture, which has great potential clinical application for bone engineering/regeneration in the future.