Microribbon‐Like Elastomers for Fabricating Macroporous and Highly Flexible Scaffolds that Support Cell Proliferation in 3D

Abstract

Hydrogel‐based scaffolds are widely used for culturing cells in three dimensions due to their tissue‐like water content and tunable biochemical and physical properties. Most conventional hydrogels lack the macroporosity desirable for efficient cell proliferation and migration and have limited flexibility when subject to mechanical load. Here microribbon‐like elastomers that, when photocrosslinked, can form macroporous and highly flexible scaffolds that support cell proliferation in 3D are developed. These microribbons are produced by wet‐spinning gelatin solution into microfibers, followed by drying in acetone, which causes asymmetrical collapse of microfibers to form microribbon‐like structures. Gelatin microribbons are then modified using methacrylate anhydride to allow further photocrosslinking into 3D scaffolds. The macroporosity and mechanical properties of the microribbon‐based scaffold may be tuned by varying wet‐spinning rate, drying temperature, choice of drying agent, level of glutaraldehyde crosslinking, and microribbon density. When encapsulated in the microribbon‐based scaffold, human adipose‐derived stromal cells proliferated up to 30‐fold within 3 weeks. Furthermore, microribbons‐based scaffold demonstrate great flexibility and can sustain up to 90% strain and 3 MPa stress without failing. The unique mechanical properties of microribbon‐based scaffolds make them promising tools for engineering shock‐absorbing tissues such as cartilage and intervertebral discs.

Gelatin-Based Microribbon Hydrogels Accelerate Cartilage Formation by Mesenchymal Stem Cells in Three Dimensions

“…Unlike HGs, while the initial compressive modulus of the macroporous mRB scaffold was low, intercrosslinking among the mRB building blocks confers upon great shock-absorbing capacity when the macroporous scaffold is subject to cyclic loading. 36 In this study, the use of mRB scaffolds led to a rapid enhancement of mechanical strength approaching the range of healthy cartilage (224.8 -19.0 kPa) after only 3 weeks of culture in vitro. This efficacy in restoration is most likely due to the inherent macroporosity of the mRB scaffold (Fig.…”

Engineering Mechanical, Biochemical, and Topographical Niche Cues by Photocrosslinkable, Microribbon-Like Hydrogels

“…This result demonstrated that the microribbons not only support 3D cell encapsulation but also provide the surface ligands to support cell engraftment and proliferation. Most interestingly, we found that the microribbons promoted ADSCs alignment along the direction of the microribbons [26]. The observed cell alignment on microribbons might have stemmed from the wet spinning procedure, which applied shear stress to the gelatin solution and promoted the self-alignment gelatin molecules and cell-binging sites.…”

Mixed Composition Microribbon Hydrogels Induce Rapid and Synergistic Cartilage Regeneration by Mesenchymal Stem Cells in 3D via Paracrine Signaling Exchange

“…Our previous method of fabricating GEL μRBs used DMSO as the solvent and requires the solution to be highly viscous . This is not suitable for CS, HA, or PEG, which are only soluble in aqueous solutions.…”