2D Gelatin Methacrylate Hydrogels with Tunable Stiffness for Investigating Cell Behaviors.

Cellular microenvironment has played a critical role in cell behavior regulation, natural tissue formation, and development. Specifically, the stiffness of extracellular matrix (ECM) not only helps cells to maintain their morphology and location but also provides physical cues to regulate cellular functions. Nevertheless, it is still hard for conventional matrix materials to explore cell behaviors and functions under their physical microenvironments due to potential long-term cytotoxicity or unphysiological stiffness. Herein, a biocompatible stiffness-tunable 2D gelatin methacryloyl (GelMA) hydrogel matrix is fabricated to explore the influence of ECM stiffness on cell morphology as well as cellular gene expression. GelMA, as a derivative of gelatin, can not only serve as cell culture matrixes due to the existence of bioactive peptide sequences and biocompatibility, but also mimic the stiffness of native ECMs. As a result, the stiffness of GelMA matrix can regulate cytoskeleton assembly and cell morphology via mechanotransduction-related genetic pathways (RhoA/ROCK and PI3K/Rac1 signaling pathway). Therefore, the 2D GelMA hydrogel matrix with tunable stiffness can be regard as an alternative cellular matrix, and has a potential to reveal the fundamental principle of ECM defect-associated diseases.