Dynamic composite hydrogels of gelatin methacryloyl (GelMA) with supramolecular fibers for tissue engineering applications
Anaïs Chalard, Harrison Porritt, Emily J. Lam Po Tang, Andrew J. Taberner, Annika Winbo, Amatul Mateen Ahmad, Juliette Fitremann, Jenny Malmström
Abstract
In the field of tissue engineering, there is a growing need for biomaterials with structural properties that replicate the native characteristics of the extracellular matrix (ECM). It is important to include fibrous structures into ECM mimics, especially when constructing scar models. Additionally, including a dynamic aspect to cell-laden biomaterials is particularly interesting, since native ECM is constantly reshaped by cells. Composite hydrogels are developed to bring different combinations of structures and properties to a scaffold by using different types and sources of materials. In this work, we aimed to combine gelatin methacryloyl (GelMA) with biocompatible supramolecular fibers made of a small self-assembling sugar-derived molecule ( N -heptyl-D-galactonamide, GalC7). The GalC7 fibers were directly grown in the GelMA through a thermal process, and it was shown that the presence of the fibrous network increased the Young's modulus of GelMA. Due to the non-covalent interactions that govern the self-assembly, these fibers were observed to dissolve over time, leading to a dynamic softening of the composite gels. Cardiac fibroblast cells were successfully encapsulated into composite gels for 7 days, showing excellent biocompatibility and fibroblasts extending in an elongated morphology, most likely in the channels left by the fibers after their degradation. These novel composite hydrogels present unique properties and could be used as tools to study biological processes such as fibrosis, vascularization and invasion. • Galactonamides can self-assemble into long fibres within a GelMA matrix to form a composite gel. • The composite gel is reinforced by the fibres and display a higher Young’s modulus. • Fibre degradation results in dynamic softening of the gel and in formation of narrow channels in the gel. • The composite gel is compatible with 3D cell culture, and the channels induce an elongated cell morphology.