Degradation-mediated cellular traction directs stem cell fate in covalently crosslinked three-dimensional hydrogels

Abstract

Although cell-matrix adhesive interactions are known to regulate stem cell differentiation, the underlying mechanisms, in particular for direct three-dimensional (3D) encapsulation within hydrogels, are poorly understood. Here, we demonstrate that in covalently crosslinked hyaluronic acid (HA) hydrogels, the differentiation of human mesenchymal stem cells (hMSCs) is directed by the generation of degradation-mediated cellular-traction, independent of cell morphology or matrix mechanics. hMSCs within HA hydrogels of equivalent elastic moduli that either permit (restrict) cell-mediated degradation exhibited high (low) degrees of cell spreading and high (low) tractions, and favoured osteogenesis (adipogenesis). In addition, switching the permissive hydrogel to a restrictive state via delayed secondary crosslinking reduced further hydrogel degradation, suppressed traction, and caused a switch from osteogenesis to adipogenesis in the absence of changes to the extended cellular morphology. Also, inhibiting tension-mediated signalling in the permissive environment mirrored the effects of delayed secondary crosslinking, whereas upregulating tension induced osteogenesis even in the restrictive environment.

Mechanical confinement regulates cartilage matrix formation by chondrocytes

“…In adherent cells, it is known that cells sense viscoelasticity through exerting traction forces at integrin-ECM ligand adhesions, gauging resistance to traction forces, and clustering ligands 18,45–48 . However, no integrin-binding cell adhesion ligands are present in the alginate hydrogels used here.…”

Self-Organized ECM-Mimetic Model Based on an Amphiphilic Multiblock Silk-Elastin-Like Corecombinamer with a Concomitant Dual Physical Gelation Process

“…Although the molecular pathways involved in cellular 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 3 mechanosensitivity are still open to investigation, it is well known that cells sense and respond to the stiffness of their environment by converting mechanical inputs into chemical outputs 5,6 . More recently, cell fate related to energy dissipation mediated by enzymatic ECM degradation has also been reported 7 .…”

Design and Characterization of a Synthetically Accessible, Photodegradable Hydrogel for User-Directed Formation of Neural Networks

“…(15)(16)(17)(18)(19)(20)(21)(22)(23) Specifically, photopatterned protein-ligand interactions have enabled the spatially controlled presentation of bioactive signaling proteins to drive stem cell migration, (12,24) orthogonal photocleavage reactions have been used to more efficiently differentiate cells by mimicking in vivo pathways, (15) and in situ photodegradation has been used to isolate the effect of cellular traction on stem cell differentiation. (25) For example, the Shoichet group developed a system exploiting strong protein-ligand interactions to immobilize gradients of sonic hedgehog protein to drive neural progenitor cell migration into an agarose gel. (12) The Lutolf group used a photoactivated enzymatic ligation to pattern gradients of VEGF to demonstrate control over mesenchymal stem cell migration.…”