Development and biomedical applications of direct-ink-writing based 3D printing hydrogel ink with high and tunable Young’s modulus

Abstract

Direct-Ink-Writing (DIW) of hydrogel holds great potential for biomedical applications due to its advantage of enabling accurate and realistic imitation of the human body easily and quickly. However, the scope of the applications has been limited to date by the range of the mechanical properties of DIW hydrogel ink, which is far less than actual biological tissues and organs. Herein, a facile method using salting out effect for manufacturing DIW hydrogel ink with high and variable Young’s modulus, which is based on Pluronic F-127 dimethacrylate (PF127DMA) aqueous solution, is introduced. In-depth analyzes and results for the effects of each monomer and salt on the behavior of micelles in the solution are presented, suggesting the possibility of tailoring the mechanical properties of the hydrogel by adjusting the content of the compositions. The developed hydrogel ink not only possesses required rheological properties for DIW but also exhibits a variable Young’s modulus of 0.193-1.072 MPa, which is the highest level and the widest range among those reported so far, to our best knowledge. Furthermore, applicability of simulating human blood vessels using the developed ink is demonstrated, including vascular surgery practices with excellent sense of reality. The biocompatibility of the hydrogel indicates the suitability of the developed material for biomedical applications and its potential for extension into a wider range of applications as well.