Construction Of Tissue Engineering Bone By Electrospinning Combined With 3D Printing Technology

Objective:Using 3D printing technology to accurately prepare the gross 3D frame,combined with electrospinning technology to prepare the microfiber scaffold for cell growth,the integrated preparation of bone tissue engineering complex provides a new solution for bone reconstruction and repair.MetHods:Using polycaprolactone(PCL)as raw material,3D printing can accurately construct 3D frames.Polyvinyl alcohol(PVA)+ Collagen Type Ⅰ(Col Ⅰ)were extracted from human umbilical vein endothelial cells.HUVECs and mouse embryonic osteoblast precursor cells(MC3T3-E1)were used as shell layers,and polyvinyl pyrrolidone(PVP)was used as core layer material for coaxial electrospinning.The cell-scaffold complex obtained from coaxial electrospinning was placed into the frame material constructed by 3D printing.At the same time,alginate hydrogel containing MC3T3-E1 cells was injected into the whole three-dimensional frame,which was used as the experimental group.PVA+Col Ⅰ was used as the shell layer and PVP as the core layer for coaxial electrospinning.The receiving device was a roller.HUVECs and MC3T3-E1 cells were dropped onto the prepared film and then combined with the 3D printing scaffold.Transmission electron microscopy(TEM)was used to observe the coaxial structure of electrospinning.Live/Dead staining was used to evaluate the cytocompatibility of the scaffold.CD31 immunofluorescence staining was used to evaluate the angiogenesis ability in vitro.Micro CT,HE staining and Masson staining were used to evaluate osteogenesis ability in vivo.Results:Transmission electron microscopy(TEM)showed that the electrospun fibers with a core/shell structure.Live/Dead staining experiment and scanning electron microscopy(SEM)showed that HUVECs and MC3T3-E1 were more evenly distributed in the electrospun fibers.CD31 immunofluorescence showed that the scaffolds with coaxial electrospinning cells had better angiogenesis than the scaffolds with direct cell dripping on the constructed scaffolds.Alizarin red and alkaline phosphatase staining in vitro showed good proliferation and osteogenic differentiation of MC3T3-E1 cells.The results of Alamar Blue showed that cell proliferation in the experimental group was more obvious than that in the control group.Micro CT results showed that at 4 and 8 weeks after the cell-scaffold complex was implanted into the skull defect of SD rats,the new bone mass in the experimental group was higher than that in the control group.HE staining and Masson staining both proved that the former was better than the latter.Conclusions:The results show that electrospinning combined with 3D printing technology can effectively solve the problem of bone defect repair,and can improve the possibility of vascularization of new bone tissue compared with traditional scaffold construction technology.