摘要：Since 3D printed hard materials could match the shape of bone,cell survival and fate determination towards osteoblasts in such materials have become a popular research *** this study,a scaffold of hardmaterial for 3D fabrication was designed to regulate developmental signal(Notch)transduction guiding osteoblast *** established a polycaprolactone(PCL)and cell-integrated 3D printing system(PCI3D)to reciprocally print the beams of PCL and cell-laden hydrogel for a *** PCI3D module holds good cell viability of over 87%,whereas cells show about sixfold proliferation in a 7-day *** osteocytic MLO-Y4 was engineered to overexpress Notch ligand Dll4,making up 25%after mixing with 75%stromal cells in the PCI3D *** Dll4,unlike other delta-like family members such as Dll1 or Dll3,promotes osteoblast differentiation and themineralization of primary mouse and a cell line of bone marrow stromal cells when cultured in a PCI3D module for up to 28 ***,osteocytic Dll4 could not promote osteogenic differentiation of the primary bone marrow stromal cells(BMSCs)after conditional deletion of the Notch transcription factor RBPjκby Cre *** data indicate that osteocytic Dll4 activates RBPjκ-dependent canonical Notch signaling in BMSCs for their oriented differentiation towards ***,osteocytic Dll4 holds a great potential for angiogenesis in human umbilical vein endothelial cells within *** study reveals that osteocytic Dll4 could be the osteogenic niche determining cell fate towards *** will open a new avenue to overcome the current limitation of poor cell viability and low bioactivity of traditional orthopedic implants.