Muti-interactions based 3D-printed osteochondral biomimetic scaffold for BMP-2 sustained release

Osteochondral defects pose significant challenges in tissue regeneration due to the complex structure and composition of native tissue. Restoring the intricate structure and functional capacity of tissues remains a formidable task in osteochondral transplantation. In this study, a novel composite crosslinked 3D printing ink was designed to construct a biomimetic osteochondral scaffold with a sustained release bone morphogenetic protein 2 (BMP-2) hydrogel system of dopamine-modified hyaluronic acid (HAD) and BMP-2 interaction. The enzyme-linked immunosorbent assay results showed a cumulative release of BMP-2 reaching 48.3 %±6.1 % at 28 days. Theoretical calculations indicated that the binding affinity of HAD and BMP-2 was −41.8 ± 1.27 kJ/mol. These findings corroborated the outstanding sustained release efficacy of the hydrogel scaffolds due to the HAD and BMP-2 interaction. Biological function evaluations revealed that the scaffolds possessed significant osteogenesis and chondrogenesis abilities in vitro. This effect is attributed to the hydrophilic nature of the upper layer of the scaffold and the sustained release of BMP-2 from the lower layer. Ultimately, the bilayer scaffolds achieved integrated osteochondral regeneration in a rat model. These results demonstrated the potential of the 3D-printed biomimetic scaffolds with a sustained release BMP-2 hydrogel system for osteochondral repair. © 2024 Elsevier Ltd