Study On Preparation And Properties Of Visible Light Curable Polyethylene Glycol Diacrylate Based 3D Printing Ink

3D biopprinting is a tissue engineering technology that uses living cells and biological materials as raw materials to print scaffolds layer by layer that can be used for transplantation.It can precisely control the positioning of biological materials,living cells and functional components in each layer.Photocurable 3D bioprinting is a kind of 3D printing technology that has attracted much attention in recent years.Compared with traditional extrusion and inkjet printing,it has better repeatability,faster printing rate and higher printing accuracy.Therefore,photocurable 3D bioprinting has become a very promising technology,which can be used to construct 3D simulated tissue structures for tissue regeneration,drug screening and disease studies,etc.This study explored the photocurable 3D bioprinting initiator system,and prepared a 3D printing ink initiated by visible light,and studied its performance and application.The specific research contents are as follows:(1)Preparation and performance evaluation of visible light curable 3D bioprinting ink.Riboflavin(RF)and L-arginine with excellent biocompatibility were selected as visible light initiation system,and polyethylene glycol diacrylate(PEGDA)was used as polymer monomer.A rotary rheometer was used to track the dynamic crosslinking process of the ink under light.The optimal formulation was determined when the concentration of riboflavin and L-arginine were 0.01 wt% and 5.4 wt% of PEGDA,respectively.Then the mechanical properties and swelling properties of the ink were characterized to provide reference for future applications.The relevant printing parameters were optimized for the ink formula,and the printing accuracy was tested and improved.The complex 3D structure was built,and the printing accuracy reached 100 ?m.(2)4D printing technology adds a time dimension to 3D objects,and printed parts can change their shape according to time and other environmental parameters such as temperature,pressure,humidity,etc.By adjusting the illumination time and illumination distribution during the 3D printing process,the hydrogel structure with patterned local cross-linking density was prepared.When hydrogels swell in liquid,the parts with different cross-linking densities will deform due to different swelling degrees and inconsistent volume changes.This experiment explores the influence of illumination time on the degree of object deformation.At the same time,temperature also has different effects on the structure of the hydrogel network with different cross-linking densities.The lower the cross-linking density,the greater the swelling change caused by temperature and the larger the volume change.A smart responsive hydrogel which can produce temperature-driven reversible deformation in liquid environment was designed based on the characteristics of different volume changes.