Biomimetic lattice-based architected prosthesis for accurate replication of the intervertebral disc multiaxial mechanics – BIOPRIME

Despite the remarkable evolution of the intervertebral disc prostheses over recent years, it remains so far, the least preferred medical solution by surgeons and the least valued by patients for the treatment of damaged discs. The existing prostheses are not yet able to mimic many major mechanical properties of the natural intervertebral disc such as auxecity and energy absorption along with their regional dependency. This does not allow them to reproduce a correct mechanical behaviour and affects the post-operative health status of treated patients. The aim of the current project is to develop new bioinspired lattice-based prostheses capable of replacing damaged intervertebral discs. Inspired by the real structure of the human intervertebral disc, the shape and materials used to design and create the prostheses should perfectly replicate the mechanical behaviour of the disc soft tissues in terms of regional dependency, axial-circumferential rigidities, and damping features related to viscoelastic and auxetic properties. The mechanical behaviour of the new designs should be controlled in a rational way by adapting the mesostructure and the microstructure of the used material. Novel cellular-based structures will be designed to add complex mechanical properties to the prosthesis such auxecity and energy absorption. Biocompatible polymer-based materials will be employed to ensure an optimal adaptation with the physiological medium of the body. The best structure/material combination with the most realistic mechanical properties will be selected to replace each region of the intervertebral disc in the designed protheses. The biomimetic capabilities of the proposed prostheses will be tested via numerical simulations then compared to those of the real disc. Once validated in silico, the new designs will be printed using advanced 3D printing technologies, then tested experimentally.