Nanopatterned Adhesive, Stretchable Hydrogel to Control Ligand Spacing and Regulate Cell Spreading and Migration

Abstract

Spatial molecular patterning enables the regulation of adhesion receptor clustering and can thus play a pivotal role in multiple biological activities such as cell adhesion, viability, proliferation, and differentiation. A wide range of nanopatterned, adhesive interfaces have been designed to decipher the essence of molecular-scale interactions between cells and the adhesive interface. Although an interligand spacing of less than 70 nm is a proven prerequisite for the formation of stable focal adhesions, there is a paucity of data concerning how cells behave on substrates featuring heterogeneous adhesiveness. In this study, a stretchable hydrogel functionalized with a quasi-hexagonally arranged nanoarray was stretched along one direction, resulting in ligands periodically arranged in a pattern resembling a centered rectangular lattice with an interligand spacing smaller than 70 nm in one direction and greater than 70 nm in the orthogonal direction. This substrate was utilized to modulate interligand spacing and investigate cell adhesion and migration. An interligand spacing larger than 70 nm-even in just one direction-prevented the establishment of stable focal adhesions. The stretched interface promoted dynamic remodeling at cell contacts, resulting in higher cellular mobility. Our nanopatterned stretchable hydrogel permits reversible control over cell adhesion and migration on nanopatterned ligand interfaces.

Characterization of thin gelatin hydrogel membranes with balloon properties for dynamic tissue engineering

“…Prior published stretchable hydrogels rely on complicated casting procedures such as purification of proteins, 3D printing, integration of magnets, nanopatterned hydrogels, nanocomposition of clay nanosheets, or a mixture of natural and synthetic polymers . Whereas, the presented method only requires mixing gelatin and mTG.…”

“…Unsupported dynamic cell‐laden hydrogels have been achieved by adding cells in a collagen hydrogel into a 3‐dimensional (3D) printed mesh of a stretchable poly(ethylene glycol)‐alginate‐nanoclay hydrogel . Other approaches include integration of magnets that could be used for stretching the hydrogel or by seeding cells on top of a hydrogel for uniaxial stretch by moving the ends of the hydrogel apart . However, all these approaches solely achieve a 2D stretch whereas we aim for achieving a 3D expandable hydrogel balloon.…”

“…[20] Other approaches include integration of magnets that could be used for stretching the hydrogel [21,22] or by seeding cells on top of a hydrogel for uniaxial stretch by moving the ends of the hydrogel apart. [23] However, all these approaches solely achieve a 2D stretch whereas we aim for achieving a 3D expandable hydrogel balloon.…”

Polyproline Tri‐Helix Macrocycles as Nanosized Scaffolds to Control Ligand Patterns for Selective Protein Oligomer Interactions

“…For instance, the T cell receptor (TCR) clustering pattern at immunological synapse has been manipulated using a supported bilayer membrane on an obstructed silica surface to study the mechanism of TCR signaling . In another example, cell surface adhesion receptor integrin has been investigated by controlling the presentation of ligands on the surface to study the cell behaviors such as adhesion, polarization, migration, stem cell differentiation, and dedifferentiation . In such studies, the patterns of the “patches” that arose from the ensemble of multiple integrin ligands were created through top‐down approaches, including nanoparticle self‐assembly on surface or various lithographic methods to allow the ligand patches distributed for tens to over a hundred nanometers apart with macroscopic patch patterns.…”

“…Therefore, our scaffold has good potential to display GPCR ligands in specific patterns to study the arrangement of GPCR complexes on membranes as well as the effects of GPCR costimulation, which are otherwise difficult to investigate through current available tools. In addition, compared to ligand patch patterns on glass slides or other surfaces created from top‐down approaches, our scaffold provides promising therapeutic potentials to manipulate cell surface receptors or target secreted lectins as the PP3M scaffold is water soluble and biocompatible. Furthermore, our scaffold benefit from the proteolytic resistant feature of polyproline helix in serum that may extend the lifetime of the ligand–scaffold conjugates in the circulation.…”