Description: An osteochondral (OC) defect is a focal area of joint damage that involves both the articular cartilage and the underlying subchondral bone. Such joint damage is strongly associated with the development of premature osteoarthritis, motivating the development of novel strategies to regenerate OC defects. 3D printing is enabling the manufacturing of geometrically complex biomaterial implants with user defined compositions and architectures, which can potentially be used as single stage, off-the-shelf scaffolds for treating complex injuries. Despite significant progress in this field, 3D printed scaffolds capable of regenerating OC defects remain elusive. This can potentially be linked to the spatial resolution possible using traditional additive manufacturing techniques. The melt electrowriting (MEW) technique has recently emerged as a novel additive manufacturing platform capable of producing polymeric scaffolds with fiber diameters in the submicron range in a highly controllable manner. We have recently developed MEW scaffolds that support superior bone regeneration compared to scaffolds produced using traditional additive manufacturing techniques. Furthermore, we have generated preliminary data demonstrating that multi-layered scaffolds generated by MEW are capable of enhancing the repair of critically sized OC defects in a pre-clinical large animal model. The MEMS project aims to further enhance the regenerative capacity of these MEW OC scaffolds by (i) optimising their architecture, and (ii) functionalizing their surface with extracellular matrix (ECM) components supportive of tissue-specific regeneration. The output of MEMS will be an off-the-shelf implant capable of directing endogenous OC defect regeneration without the need for delivering exogenous cells to the defect site. Funded by: European Research Council.