3D printing of osteocytic Dll4 integrated with PCL for cell fate determination towards osteoblasts in vitro

Abstract

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 target. In this study, a scaffold of hard material for 3D fabrication was designed to regulate developmental signal (Notch) transduction guiding osteoblast differentiation. We established a polycaprolactone (PCL) and cell-integrated 3D printing system (PCI3D) to reciprocally print the beams of PCL and cell-laden hydrogel for a module. This PCI3D module holds good cell viability of over 87%, whereas cells show about sixfold proliferation in a 7-day culture. The osteocytic MLO-Y4 was engineered to overexpress Notch ligand Dll4, making up 25% after mixing B Xiaolin Tu

A Highly Selective GSK-3β Inhibitor CHIR99021 Promotes Osteogenesis by Activating Canonical and Autophagy-Mediated Wnt Signaling

“…Finally, we validated in vivo osteogenesis function of C91, the PCCI3D module was printed with our newly established PCL and cell-integrated 3D printing (PCI3D) system ( 19 ) to simulate the real in vivo osteogenesis process. The PCL bundle is printed at the bottom of the module, the GelMA hydrogel bundle loaded with ST2 cells is printed in the middle, and the GelMA hydrogel bundle loaded with C91 is printed in the upper part, and the three bundles are printed alternately for a total of 4 layers.…”

“…Cells and C91 were individually mixed with an equal volume of GelMA solution for 3D bioprinting. The cell-loaded GelMA solution and the C91-loaded GelMA solusion were reciprocally printed out at 25°C as cell beams in a diameter of 300μm with an interval of 500μm between cell beams at a printing speed of 5 mm/s ( 19 ). After the printing of one layer, the GelMA hydrogels were crosslinked under blue light at 405 nm for 10 s. Then, printing was continued for another layer.…”

“…2.4 PCL, C91, and Cell-Integrated 3D Printing (PCCI3D) 3D printing was performed as reported (19), GelMA hydrogel was used to laden cells and C91 drags.10 mM of C91 and 2 x 10 5 ST2 cells were each mixed with 0.25 mL of a-MEM. Cells and C91 were individually mixed with an equal volume of GelMA solution for 3D bioprinting.…”

“…However, autophagy cannot reverse the inhibition of Wnt signaling antagonist Triptonide on C91-induced osteogenic differentiation ( Figure 8F ). To evaluate in vivo function of C91, a 3D printed artificial bone scaffolds by using our newly established integrated 3D printing of polycaprolactone and cells ( 19 ) verified that slow releasing C91 on 3D modules promotes the osteogenic differentiation and mineralization of ST2 cells with good survival rate and growth of ST2 cells. Thus, the small molecule Wnt agonist C91 has translational application value in maintaining bone marrow stromal cell for osteogenesis through canonical and autophagy-mediated Wnt signaling.…”

A novel decellularized matrix of Wnt signaling-activated osteocytes accelerates the repair of critical-sized parietal bone defects with osteoclastogenesis, angiogenesis, and neurogenesis

“…The invention of hard material and cell integrated 3D bioprinting technology [ 6 , 7 ] has successfully realized the personalized adaptation of hard material scaffolds with mechanical support, creating a suitable biological microenvironment for cell adhesion, proliferation, and differentiation, so as to meet the challenges faced by orthopedic materials. However, the application of exogenous living cells still has the limitations of ethical supervision and approval, standardized technology, and high cost, as well as the deficiencies of cell survival rate, proliferation, function maintenance, and rejection [ [8] , [9] , [10] ].…”