The Experimental Study Of 3D Printed GO-HEMA-PTMC Scaffold Combined With ADSCs To Repair Critical Bone Defect In Rat Skull

Objective: 1.Prepare photosensitive resin ink suitable for photocuring 3D printing technology,graphene oxide-hydroxyethyl methacrylate-polytrimethylene carbonate(GOHEMA-PTMC)and print three-dimensional three-dimensional scaffolds through 3D printing technology.Characterize the physical properties of the scaffold and analyze its degradability.2.Rat adipose-derived stem cells(rADSCs)were isolated and seeded on the surface of scaffold materials,and their biological characteristics such as cell adhesion,proliferation,and osteogenic differentiation were studied in vitro.3.Comparing the ability of different scaffold materials to promote bone defect repair through the experiment of critical bone defect repair in rat skull.Methods: 1.Synthesis of HEMA-PTMC with different molecular weights by opening the trimethylene carbonate(TMC)ring.A photosensitive resin suitable for 3D printing is made by adding graphene oxide,non-reactive diluent,photosensitizer,etc.Select a suitable molecular weight resin product and print it into a scaffold system by photo-curing 3D printer,characterize the physical properties of the scaffold,and analyze its degradation.2.Test the viability,proliferation and endocytosis of rADSCs on the scaffold,and detect the osteogenic effect of rADSCs after osteogenesis induction by alkaline phosphatase(ALP)activity test.3.Active artificial bone formed by transplanting different groups of scaffolds combined with adipose-derived stem cells to study its effect on the repair of critical bone defects in rat skulls.Results: The photo-cured 3D printing scaffold system designed and synthesized in this experiment has excellent mechanical properties,biocompatibility and suitable degradation rate.The results showed that the water absorption of the scaffold system modified by graphene oxide(GO)increased by 10.4%,the elastic modulus increased by 52%,and the compressive strength increased by 13.14%.GO-modified scaffolds can promote early cell adhesion and stimulate early cell proliferation.The results showed that the planting efficiency increased by 12%,and the proliferation efficiency increased significantly in the first seven days and was most significant on day 3 and day 5(P<0.001).In the GO modification group,the early expression of ALP in rADSCs after induction of osteogenesis was more obvious(P<0.05),and the expressions of OPN and RUNX-2 were also higher than those in the unmodified group(P<0.05).The rADSCs endocytosis experiment of PKH67-labeled exosomes showed that the cells grown on the scaffold had normal endocytosis and exocytosis,and the scaffold did not affect the functional activity of the cells.Printed scaffolds containing graphene oxide can promote osteogenesis repair in vivo.The results showed that GO-modified bone formation was the fastest,with the largest amount of bone formation,and the BV/TV value was higher than that of the unmodified group(P<0.05),suggesting that printing GO-HEMA-PTMC scaffolds have the best effect on promoting bone defect healing.Conclusion: The experimentally prepared composite adipose stem cell GO-HEMAPTMC scaffold has good physical properties,biocompatibility,disease organ model simulation,etc.It has the potential as an implantable scaffold.The whole system showed good cell proliferation without affecting normal endocytosis.Compared with the HEMAPTMC scaffold alone,the GO-modified scaffold had a better early-stage pro-proliferation effect,and the early expression of ALP in rADSCs after induction of osteogenesis was more pronounced,and the effect on bone defect healing was more significant.In future experiments,we will further discuss the possibility of its clinical application.