3D Bio-Printing Of Vessel-Like Constructs And Its Applications

In recent years,3D bio-printing technology has developed rapidly.With the deepening of people's research,the liver,blood vessels,functional skin and vascularized tissue based on 3D bio-printing have been reported.However,due to the high cost of bio-printing equipment and the lack of a variety of bio-printing materials,the popularization and rapid development of 3D bio-printing technology are limited.Especially for printing small caliber tubular structures,it requires complex 3D bio-printing equipment and printing process.In this project,we developed a new type of bio-ink,and we build a low cost and integrated biological 3D printer with independent intellectual property.On the basis of this,we invented a new type of small caliber tubular structure printing method.The principle of this method is: We print the biological ink through the printer in the matrix solution,and form a small caliber tubular structure by controlling the degree of crosslinking of the biologic ink in the matrix solution.We control the inner diameter and outer diameter of the tubular structure by controlling the cross-linking time.Subsequently,we planted vascular endothelial cells on the inner wall of the printed tube to simulate vascular structure,and explored the application of "print blood vessel" in the construction of pathological model.The research contents include:1?We transform the basic framework of desktop plastic 3D printer and build a low-cost,temperature controlled biological printer.2?We added some Pluronic F127 in biological ink based on gelatin to improve the 3D printing adaptability of the original biological ink,and the biological ink has good biocompatibility.3?We have developed a simple method of blood vessel printing: we use a biological printer to squeeze out the biological ink at a certain speed from the syringe,control the degree of crosslinking of sodium alginate in the mixed biological ink,and then we wash out the middle part of the non-crosslinked and print out the medium tubular structure.We can get tubular structures with different diameter(1.5mm-5mm)and different wall thickness by controlling the printing parameters.In order to simulate the structure of blood vessels,we explored the way of planting endothelial cells in printing blood vessels.4?We used homocysteine to induce the printing blood vessels to construct the atherosclerotic pathological model preliminarily and we observed pathological changes of endothelium in the early stage of atherosclerosis induced by homocysteine.