Research On 3D Printing Technology Of Composite Skull Scaffold

In view of the skull defect problems,the main clinical implementation of the skull repair is the use of bone tissue engineering scaffold as a graft to repair the skull defect,which has been widely recognized by scholars.This paper develops a high-precision,low-cost Bio-3D printer,prepares a good bio-ink for encapsulating cells,studies various aspects of hydrogel and cell viability of Cell-Gel hydrogel under different printing conditions.Finally,composite skull scaffold was manufactured using Bio-3D printing technology.Firstly,based on the high-precision three-axis motion platform,a high-precision,low-cost double-head extrusion Bio-3D printer has been developed,which can realize the integrated preparation of composite tissue engineering scaffold,in which the hightemperature printing extrusion device can print granular or powdery biomaterials with melting points below 250°C with a resolution of 100μm.The low temperature printing extruder can easily replace a variety of length specifications of Ruhr needles and print a variety of different bio-inks.This extruder resolution can reach 60μm.Secondly,a good bio-ink was prepared for encapsulating cells,and gelatin was used as a matrix material to adjust the viscosity,water absorption and degradability of the hydrogel material by changing the content of sodium alginate.The overall hydrogel water absorption performance is excellent;the degradability test shows that the lower the SA content,the faster the degradation rate,and the degradation rate gradually decreases with time.The cell survival rate of Gel/SA encapsulated cells after printing is over 65%.The survival rate of cells after 72 h static culture is still more than 62%,indicating that the hydrogel material can supply nutrients to the cells inside the gel.After comprehensive evaluation,5%Gel + 0.5%SA is considered to be the optimal formula.Finally,the toxicity and degradability of the bone PCL scaffold in the composite skull scaffold were tested.The results showed that PCL had no toxic side effects on the cells;PCL material,osteoblast(MC3T3-E1)and optimal formula 5% Gel+ 0.5% were selected,then using a high temperature nozzle(?0.3mm)and 27G(?0.21mm)to print a PCL-Cell-Gel/SA composite skull scaffold.This research has realized a complete research and development process from the development of Bio-3D printer to print the composite skull scaffold.It provides good hardware technical basis for the preparation of composite tissue engineering scaffolds,provides a good bio-ink preparation scheme,and promotes the skull repair technique to the clinical application stage a little in some way.