Rational design and additive manufacturing of alumina-based lattice structures for bone implant

Porous scaffolds can be used for treating bone defects. To manufacture porous scaffolds similar to bone, two types of ceramic scaffolds with different porosity, namely, octagon and rhombus scaffolds were designed and fabricated by Digital Lighting Process technology. Compression test, finite element analysis, computational fluid dynamics (CFD), and in vitro cell experiment were conducted for systematic investigation of the properties of the scaffolds. The results showed that the elastic modulus of alumina octagon and rhombus lattice structure was within 0.5–4 GPa. Through the CFD simulation, the permeability of the scaffold was found to be in the range of 4.10 × 10−9 to 2.32 × 10−8 m2 and the wall shear stress of different structures ranged from 4.9 × 10−4 to 84.4 mPa. Live/dead staining and Cell Counting Kit-8 assay showed that all groups were biocompatible and beneficial to cell proliferation except for octagon structure with 1.049 mm pore and rhombus structure with 0.6 mm pore. Analysis of the results of the mechanical properties, CFD simulations, and in vitro cell studies indicated that the porous scaffolds suitable for bone engineering were 0.566 mm-pore-size octagon unit and 1.0 mm-pore-size rhombus unit with elastic modulus of 3834.9 and 599.8 MPa, respectively.