Bioprinting the Osteochondral Interface: Advances, Challenges, and Future Directions

Osteochondral (OC) defects, involving simultaneous damage to articular cartilage and subchondral bone, remain clinically challenging due to the distinct biological, mechanical, and structural characteristics of each layer. Traditional repair techniques are limited by poor integration and inadequate tissue regeneration. 3D bioprinting has emerged as a promising strategy to fabricate biomimetic OC constructs with precise spatial control over scaffold architecture, cell distribution, and bioactive cues. This review summarizes recent advancements in additive manufacturing techniques and their applications in OC tissue engineering. Scaffold design strategies are discussed, along with the selection of biofunctional materials. Special focus is given to recent progress in bioink development, including the precise incorporation of growth factors, zonal patterning of stem cells to guide region-specific differentiation, and the integration of bioceramics to enhance osteogenic potential while supporting chondrogenic matrix formation.