3D-printed, bi-layer, biomimetic artificial periosteum for boosting bone regeneration

Periosteum, a membrane covering the surface of bone, plays an essential role in maintaining function bone tissue—and especially providing nourishment and vascularization during regeneration process. Currently, most artificial periostea have relatively weak mechanical strength rapid degradation rate, they lack integrated angiogenesis osteogenesis functions. In this study, bi-layer, biomimetic, periosteum composed methacrylated gelatin–nano-hydroxyapatite (GelMA-nHA) cambium layer poly (N-acryloyl 2-lycine) (PACG) -GelMA-Mg2+ fibrous was fabricated via 3D printing. The GelMA-nHA is shown to undertake improving osteogenic differentiation rat marrow mesenchymal stem cells with sustainable release Ca2+ from nHA nanoparticles. hydrogen-bonding-strengthened P(ACG-GelMA-L)-Mg2+ hydrogel serves protect inner defect site prolong time (60 days) match new regeneration. Furthermore, released magnesium ion exhibits prominent effect regulating polarization phenotype macrophage into M2 thus promotes human umbilical vein endothelial vitro. This bi-layer implanted critical-sized cranial rats, 12-week post-operative outcomes demonstrate optimal