摘要：Extrusion-based 3D bioprinting is a direct deposition approach used to create three-dimensional(3D)tissue scaffolds typically comprising *** are hydrated polymer networks that are chemically or physically ***,3D bioprinting is performed in air,despite the hydrated nature of hydrogels and the potential advantage of using a liquid phase to provide cross-linking and otherwise functionalize the *** this work,we print gelatin alginate hydrogels directly into a cross-linking solution of calcium chloride and investigate the influence of nozzle diameter,distance between nozzle and surface,calcium chloride concentration,and extrusion rate on the dimensions of the printed *** hydrogel layer height was generally found to increase with increasing extrusion rate and nozzle distance,according to the increased volume extruded and the available space,*** addition,the hydrogel width was generally found to increase with decreasing nozzle distance and cross-linking concentration corresponding to confinement-induced spreading and low crosslinking regimes,***/height ratios of^1 were generally achieved when the nozzle diameter and distance were comparable above a certain cross-linking *** these relationships,biocompatible 3D multilayer structures were successfully printed directly into calcium chloride cross-linking solution.

摘要：Brain tumors’severity ranges from benign to highly aggressive and *** tools can assist in understanding the pathophysiology of these tumors from outside the body and facilitate development of suitable antitumoral ***,we first describe the physiology and cellular composition of brain ***,we discuss the development of threedimensional tissue models utilizing brain tumor *** particular,we highlight the role of hydrogels in providing a biomimetic support for the cells to grow into defined *** technologies,such as electrospinning and bioprinting,and advanced cellular models aim to mimic the extracellular matrix and natural cellular localization in engineered tumor ***,we review current applications and prospects of hydrogels for therapeutic purposes,such as drug delivery and co-administration with other *** further development,hydrogels can serve as a reliable option for in vitro modeling and treatment of brain tumors for translational medicine.