Preparation and Properties of Direct Ink Writing 3D Printing Hydrogel Ink Based on Dynamic Boronic Ester Bond

ABSTRACT Hydrogels, owing to their excellent biocompatibility, high water content, and adjustable physicochemical properties, have become indispensable biomaterials in the field of 3D printing. The dynamic boronic ester bond is a reversible covalent bond that can form and dissociate under specific conditions, endowing materials with robust self‐healing capabilities and high sensitivity to external stimuli. By carefully designing materials utilizing dynamic boronic ester bonding, we developed an innovative polymer hydrogel that combines high stability and dynamic characteristics. Specifically, 3‐aminophenylboronic acid (PBA) was successfully grafted onto the natural polysaccharide sodium alginate (SA), resulting in the SA‐PBA moiety. Dynamic boronic ester bonds were then formed by combining SA‐PBA with polyvinyl alcohol (PVA) and MXene (Ti3C2Tx), ultimately yielding SA‐PBA/PVA/MXene 3D printable hydrogel ink (SPPM‐h). The incorporation of MXene was intended to enhance the conductivity of the hydrogel. After thoroughly characterizing the composition and structure of SPPM‐h, we conducted an in‐depth evaluation of its key properties, including rheological behavior, self‐healing ability, and tensile performance. SPPM‐h exhibited remarkable self‐healing properties, achieving complete self‐repair within just 30 s after fracture—significantly faster than some hydrogels reported in the literature, which require up to 24 h for repair. The conductivity of SPPM‐h 3D printing hydrogel ink is approximately 0.034 S/m. Additionally, it demonstrates good adhesion on various types of surfaces, offering broad prospects for applications in direct ink writing 3D printing.