Abstract:

Tissue engineering and regenerative medicine are being investigated as therapeutic options for diseases involving cartilage and bone damage in osteochondral tissue. In addition, it represents a significant challenge to develop scaffolds to deal with osteochondral lesions due to the microstructural complexity of this tissue, the change in mechanical properties with depth and the presence of distinct cell types (chondrocytes and osteoblasts). Furthermore, the use of biodegradable materials is crucial for treatment success. Unlike permanent implants, which remain in the body as foreign materials after the healing process and may require second surgeries for removal due to inflammatory responses, bioresorbable implants can be gradually degraded and absorbed in the human body. As a result, after degradation, only the natural tissue remains.

There are different techniques to manufacture bioabsorbable scaffolds with a gradient structure in composition and mechanical properties, but Fused Filament Fabrication (FFF) is one of the most suitable technologies. FFF allows the fabrication of customised structures and the use of a wide range of polymer-based materials.

The aim of this thesis is to design, manufacture and characterise 3D printed bioabsorbable multimaterial gradient scaffolds that provide an optimal solution for the regeneration of osteochondral defects. Therefore, first-year methodology, results and conclusions are focused on the fabrication and characterisation of continuous wire-reinforced polymers in order to reach the mechanical properties of cortical subchondral bone. Despite its great potential, limited research has been carried out. As a result, during this first year of PhD, it has been performed the first complete study of 3D printed unidirectional wire-reinforced polymers along both longitudinal and transverse directions, and the fabrication –for the first time– of multidirectional wire-reinforced polymers manufactured by means of FFF.