3D Printed Anti-Swelling Hydrogel Scaffold with Dialdehyde Cellulose Nanocrystal

Abstract

In this study, a novel hydrogel preparation method is developed to formulate a 3D printable hydrogel with low swelling ratio for bio-medical scaffold. Nanocellulose fibrils is first oxidized to synthesize dialdehyde cellulose nanocrystal (DAC). The aldehyde groups on DAC can crosslink with laponite nanoclay via an esterification reaction. The mechanism between the two materials through aldehyde and hydroxyl groups is further confirmed by FTIR results. To optimize the printability and printing quality of the prepared hydrogels, the rheological properties of the gels are carefully examined to understand the shear thinning effect and the thixotropic responses. An optimal hydrogel composition of 6 wt% Laponite and 1 wt% DAC shows the best results to accurately print 3D structures with a nozzle dispenser. The printed gel structures show high mechanical strength and low swelling effect without complicated after-treatment steps. Several examples are also demonstrated to show the structural stability, accuracy, and cell viability of the printed hydrogel structures for potential in 3D bioprinting applications.