Biomimetic Interface Design and Finite Element Optimisation for Osteochondral Composite Scaffold

Abstract

A method of biomimetic interface design and multi-objective optimisation is presented for the aim of preventing the interfacial delamination of composite scaffolds for the osteochondral tissue engineering application. The engineering structure model(6.7±0.71% of surface porosity and 40°-50° or 80°-90° of distribution angle) is firstly established from the surface characterization of subchondral bone plate, following the biomimetic interface model and finite element models of the osteochondral composite assembled by PEGDA hydrogel chondral compound and β-TCP ceramic bone compound fabricated using laser stereolithography and ceramic sintering techniques. Combined with multi-objective optimisation approach, the parameters, that is, the diameter of pore, structural unit(triangular, quadrilateral or hexagonal unit), pore spacing(or side length), surface porosity, are identified as playing an important role in the pore formibility and interfacial delamination between the PEGDA hydrogel and β-TCP ceramic compound of osteochondral composite. The optimized interfacial structure is defined as having the charactizations of quatrilateral unit, surface porosity in a range of 5%-15%, pore diameter of more than 400 μm, which having a better capability both to achieve pore formibility and to prevent delamination. The method discussed in this paper provides a promise assessment way to integrate biomimetic design with rapid manufacturing of composite scaffold.