A Stereolithography‐Based 3D Printed Hybrid Scaffold for In Situ Cartilage Defect Repair

Damage to articular cartilage can over time cause degeneration to the tissue surrounding the injury. To address this problem, scaffolds that prevent degeneration and promote neotissue growth are needed. A new hybrid scaffold that combines a stereolithography‐based 3D printed support structure with an injectable and photopolymerizable hydrogel for delivering cells to treat focal chondral defects is introduced. In this proof of concept study, the ability to a) infill the support structure with an injectable hydrogel precursor solution, b) incorporate cartilage cells during infilling using a degradable hydrogel that promotes neotissue deposition, and c) minimize damage to the surrounding cartilage when the hybrid scaffold is placed in situ in a focal chondral defect in an osteochondral plug that is cultured under mechanical loading is demonstrated. With the ability to independently control the properties of the structure and the injectable hydrogel, this hybrid scaffold approach holds promise for treating chondral defects. When articular cartilage is damaged and a chondral defect occurs, there is loss of cartilage as well as the adjacent cartilage tissue is susceptible to degeneration. Herein, a hybrid scaffold that combines a stereolithography 3D printed support structure with an injectable, photopolymerizable cell‐laden hydrogel is developed. The potential for this hybrid scaffold to support neocartilage regeneration while minimizing degeneration of the surrounding cartilage is demonstrated.