Extracellular matrix-inspired hydrogel of hyaluronan and gelatin crosslinked via a Link module with a transglutaminase reactive sequence

Abstract

The extracellular matrix (ECM) is a natural scaffold of cells in the body. It has a complex structure comprising various proteins, such as collagen and hyaladherins, and polysaccharides such as hyaluronan (HA). Here, inspired by the crosslinked ECM structure, we design a genetically engineered Link module—LinkCFQ—by fusing a microbial transglutaminase (MTG)-reactive tag to the Link module, an HA-binding domain of tumor necrosis factor-stimulated gene-6. Although the HA-specific binding property of the Link module is preserved, LinkCFQ demonstrates excellent MTG reactivity with various proteins. Furthermore, an ECM-inspired hydrogel is fabricated from an HA–gelatin mixture crosslinked via HA/Link module interaction and MTG-catalyzed isopeptide bond formation in LinkCFQ. Cell culture and mouse experiments confirm the hydrogel’s biocompatibility and degradability. Our findings provide insights into the design of biomaterials and proteins for tissue engineering, regenerative medicine, drug discovery and delivery, disease models, biofabrication, and medical devices.