Cryoprotectant enables structural control of porous scaffolds for exploration of cellular mechano-responsiveness in 3D

Abstract

Despite the wide applications, systematic mechanobiological investigation of 3D porous scaffolds has yet to be performed due to the lack of methodologies for decoupling the complex interplay between structural and mechanical properties. Here, we discover the regulatory effect of cryoprotectants on ice crystal growth and use this property to realize separate control of the scaffold pore size and stiffness. Fibroblasts and macrophages are sensitive to both structural and mechanical properties of the gelatin scaffolds, particularly to pore sizes. Interestingly, macrophages within smaller and softer pores exhibit pro-inflammatory phenotype, whereas anti-inflammatory phenotype is induced by larger and stiffer pores. The structure-regulated cellular mechano-responsiveness is attributed to the physical confinement caused by pores or osmotic pressure. Finally, in vivo stimulation of endogenous fibroblasts and macrophages by implanted scaffolds produce mechano-responses similar to the corresponding cells in vitro, indicating that the physical properties of scaffolds can be leveraged to modulate tissue regeneration.

Amorphous Silk Fibroin Nanofiber Hydrogels with Enhanced Mechanical Properties

“…Fibroblast cells were also used to measure the cytocompatibility of the hydrogels owing to their importance as the main cellular components, promote extracellular matrix synthesize, regulate angiogenesis and tissue remodeling in regeneration process . As expected, no dead cells appeared when the cells were cultured on different hydrogels for 5 days ( Figure 7 A).…”

Rapid fabrication and screening of tailored functional 3D biomaterials

“…S1). Acrylate monomers and DMS O have been widely report ed in the production of 3D scaffolds for biomedical applications in vitro as well as in vivo [38,41]. Moreover, the conversion during the polymerisation and the efficiency of the was hing step to remove unreacted acrylate monomers was analysed by FTIR ( Fig.…”

Unraveling the mechanobiology of immune cells

“…However, macrophages show less consistent responses to scaffold stiffness across studies due to different macrophage sources and different substrate materials and stiffness [ 23 , 24 , 51 ]. A potentially confounding factor is that scaffold mechanical properties are tightly linked to pore size and thus spatial confinement, which may also contribute to macrophage polarization [ 52 ]. A new approach using the cryoprotectant dimethyl sulfoxide (DMSO) allows the control of scaffold pore size independent of stiffness, enabling researchers to evaluate individual effects of stiffness and spatial confinement on immune cell phenotype and function in porous biomaterial scaffolds [ 52 ].…”

“…A potentially confounding factor is that scaffold mechanical properties are tightly linked to pore size and thus spatial confinement, which may also contribute to macrophage polarization [ 52 ]. A new approach using the cryoprotectant dimethyl sulfoxide (DMSO) allows the control of scaffold pore size independent of stiffness, enabling researchers to evaluate individual effects of stiffness and spatial confinement on immune cell phenotype and function in porous biomaterial scaffolds [ 52 ]. Understanding the effects of material stiffness and porosity on immune cells will provide a rational basis for the design of artificial matrix to stimulate immune cell expansion ex vivo and modulate immune cell functions in situ by mimicking APCs and/or constructing an artificial niche [ 39 , 50 , 53 ].…”