3D printing of a biocompatible low molecular weight supramolecular hydrogel by dimethylsulfoxide water solvent exchange

A fragile and non-thixotropic biocompatible low molecular weight gel is printed in 3D structures by a solvent exchange process. The 3D printing process is based on the continuous extrusion of a solution of a small amphiphile molecule, N-heptyl-D-galactonamide, in dimethylsulfoxide, that forms a gel in contact with water. The diffusion of water in the dimethylsulfoxide / N-heptyl-D-galactonamide solution triggers the self-assembly of the molecule into supramolecular fibers and the setting of the ink. The conditions for getting a well-defined pattern and the dimensions of the constructs have been determined. The resulting constructs can be easily dissolved, orienting its application as a sacrificial ink or a temporary support. This method opens the way to the injection and the 3D printing of other fragile and non-thixotropic supramolecular hydrogels.