A Supramolecular Injectable Methacryloyl Chitosan-tricine-based Hydrogel with 3D printing potential for tissue engineering applications.

Printable hydrogels have attracted significant attention as versatile, tunable, and spatiotemporally controlled biomaterials for tissue engineering (TE) applications. Several chitosan-based systems have been reported presenting low or no solubility in aqueous solutions at physiological pH. Herein, we present a novel neutrally charged, biomimetic, injectable, and cytocompatible dual-crosslinked hydrogel system based on a double functionalized chitosan with methacryloyl and tricine moieties (CHTMA-Tricine), completely processable at physiological pH, with promising 3D printing potential. Tricine, an amino acid typically used in biomedicine, is capable of establishing supramolecular interactions (H-bonds) and has never been explored as a hydrogel component for TE. CHTMA-Tricine hydrogels demonstrate significantly greater toughness (ranging from 656.5±82.2 to 1067.5±121.5 kJ.m -3 ) compared to CHTMA hydrogels (ranging from 382.4±44.1 to 680.8±104.5 kJ.m -3 ), highlighting the contribution of the supramolecular interactions for the overall reinforced 3D structure provided by tricine moieties. Cytocompatibility studies reveal that MC3T3-E1 pre-osteoblasts cells remain viable for 6 days when encapsulated in CHTMA-Tricine constructs, with semi-quantitative analysis showing ca. 80% cell viability. This system's interesting viscoelastic properties allowed the fabrication of multiple structures, which coupled with a straightforward approach, will open doors for the design of advanced chitosan-based biomaterials through 3D bioprinting for TE. This article is protected by copyright. All rights reserved.