Flow-induced gelation of microfiber suspensions

Perazzo, Antonio; Nunes, Janine K.; Guido, Stefano; Stone, Howard A.

doi:10.1073/pnas.1710927114

Cited by 57 publications

(46 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finding a way to study individual microstrands and characterize the aspect ratio would allow us to study how rheological properties, as well as scaffold stability and stiffness and cell migration are influenced by microstrand aspect ratio. [ 17 ]…”

Section: Resultsmentioning

confidence: 99%

3D Bioprinting of Macroporous Materials Based on Entangled Hydrogel Microstrands

Kessel¹,

Lee²,

Bonato³

et al. 2020

Advanced Science

105

110

View full text Add to dashboard Cite

Hydrogels are excellent mimetics of mammalian extracellular matrices and have found widespread use in tissue engineering. Nanoporosity of monolithic bulk hydrogels, however, limits mass transport of key biomolecules. Microgels used in 3D bioprinting achieve both custom shape and vastly improved permissivity to an array of cell functions, however spherical‐microbead‐based bioinks are challenging to upscale, are inherently isotropic, and require secondary crosslinking. Here, bioinks based on high‐aspect‐ratio hydrogel microstrands are introduced to overcome these limitations. Pre‐crosslinked, bulk hydrogels are deconstructed into microstrands by sizing through a grid with apertures of 40–100 µm. The microstrands are moldable and form a porous, entangled structure, stable in aqueous medium without further crosslinking. Entangled microstrands have rheological properties characteristic of excellent bioinks for extrusion bioprinting. Furthermore, individual microstrands align during extrusion and facilitate the alignment of myotubes. Cells can be placed either inside or outside the hydrogel phase with >90% viability. Chondrocytes co‐printed with the microstrands deposit abundant extracellular matrix, resulting in a modulus increase from 2.7 to 780.2 kPa after 6 weeks of culture. This powerful approach to deconstruct bulk hydrogels into advanced bioinks is both scalable and versatile, representing an important toolbox for 3D bioprinting of architected hydrogels.

show abstract

Section: Resultsmentioning

confidence: 99%

3D Bioprinting of Macroporous Materials Based on Entangled Hydrogel Microstrands

Kessel¹,

Lee²,

Bonato³

et al. 2020

Advanced Science

105

110

View full text Add to dashboard Cite

show abstract

“…Many processing conditions and practical applications of soft materials can be approximated by large amplitude oscillatory shear (LAOS) because it offers independent control of the length and time scales of structural rearrangements. As such, LAOS has been widely adopted as a model transient flow protocol capable of eliciting nonlinear responses [2,19,24,[32][33][34][35][36][37][38][39][40].Typical mathematically-based descriptions of experimental responses to LAOS are based on Fourier transformation (FT), which represents the complex sequence of processes exhibited by soft materials in the time domain as a sum of harmonic contributions in the frequency domain [41], performing an averaging of sorts. Physical processes that take place sequentially over intervals of time shorter than a period of oscillation are therefore not easily discerned via such analysis methods.…”

mentioning

confidence: 99%

Structure-Property Relationships via Recovery Rheology in Viscoelastic Materials

et al. 2019

View full text Add to dashboard Cite

The recoverable strain is shown to correlate to the temporal evolution of microstructure via time-resolved small-angle neutron scattering (SANS) and dynamic shear rheology. Investigating two distinct polymeric materials of wormlike micelles and fibrin network, we demonstrate that, in addition to the nonlinear structure-property relationships, the shear and normal stress evolution is dictated by the recoverable strain. A distinct sequence of physical processes under large amplitude oscillatory shear (LAOS) is identified that clearly contains information regarding both the steadystate flow curve and the linear-regime frequency sweep, contrary to most interpretations that LAOS responses are either distinct from, or somehow intermediate between the two cases. This work provides a physically-motivated and straightforward path to further explore the structure-property relationships of viscoelastic materials under dynamic flow conditions.A long-standing challenge in understanding the out-ofequilibrium behavior of soft matter is to link microstructural rearrangements and the macroscopic flow properties. We show, via time-resolved rheo-small-angle neutron scattering (rheo-SANS), that such a link can be made, forming nonlinear rheological structure-property relations, by considering the evolution of the recoverable component of the strain.The simultaneous collection of macroscopic rheological information and particle-or molecular-level data has been used understand the interplay between material constituents that cover a wide range of length scales. Recent examples include the applications of scattering techniques in polymeric materials [1][2][3][4][5][6][7], confocal microscopy in colloidal systems [8][9][10][11][12][13][14][15][16][17][18] and simulation methods [19][20][21][22][23][24]. Despite these efforts, rheological structure-property relations remain incompletely understood. Oscillatory shearing provides a reproducible way to probe viscoelastic behaviors and has been used to study a wide array of soft materials [25][26][27][28][29][30][31]. Many processing conditions and practical applications of soft materials can be approximated by large amplitude oscillatory shear (LAOS) because it offers independent control of the length and time scales of structural rearrangements. As such, LAOS has been widely adopted as a model transient flow protocol capable of eliciting nonlinear responses [2,19,24,[32][33][34][35][36][37][38][39][40].Typical mathematically-based descriptions of experimental responses to LAOS are based on Fourier transformation (FT), which represents the complex sequence of processes exhibited by soft materials in the time domain as a sum of harmonic contributions in the frequency domain [41], performing an averaging of sorts. Physical processes that take place sequentially over intervals of time shorter than a period of oscillation are therefore not easily discerned via such analysis methods. The lack of a generic understanding of the higher harmonics [42] has limited the widespread adoption of these met...

show abstract

“…Recently, a new class of hydrogel gelation was discovered. A highly biocompatible hydrogel can be produced from a suspension of highly flexible fibers with the shear thickening behavior caused by the irreversible formation of topological entanglements of the fibers …”

Section: Microfluidics Fabrication Of Soft Microtissues and The Bottomentioning

confidence: 99%

Microfluidics Fabrication of Soft Microtissues and Bottom‐Up Assembly

Mukherjee

2018

Adv. Biosys.

View full text Add to dashboard Cite

recapitulate the structure, cellular organization, and functions of their native counterparts. Though the size is usually up to three orders of magnitude smaller than the native organs, the miniaturized organ model retrieves the multicellular and cellmatrix interactions, and holds the promise to recapitulate some critical functions of native organs. [8] On the other hand, shortage of organs available for transplantation, and the risk of infection and organ rejection coupled with allotransplantation-associated immunosuppression call for the development of engineered organs based on acceptor's genetic information and tissue material (like patient-induced pluripotent stem cell derived differentiated cell lines). [11,12] Modular assembly of microtissues, [13] either in vitro followed by culture and transplantation, or in vivo, such as in situ printing, [14] has become a promising approach to engineer artificial organs across a wide range of scales for regeneration or repair purposes.Hydrogels are a class of polymeric materials that hold large amounts of water in the 3D networks, and have been widely used as the artificial biomaterial to mimic the cellular environment supporting the living tissue networks. [15][16][17] Hydrogels can be either natural or synthetic. [17] Here, we will primarily introduce the microfluidics-based fabrication of hydrogel microtissues in the form of modular structures and microfibers, with a particular focus on one specific class of materials that provides a more native environment to cells, the extracellular matrix (ECM) or ECM-like materials. [18] Microfluidics is a revolutionary platform that manipulates fluids across a wide range of viscosity, [19,20] and has emerged as a powerful technique to miniaturize fluids into microscale and manipulate the fluids online, including mixing, merging, splitting and reaction, etc. [20][21][22] The continuous flow manner can produce various microfibers, [23] whereas droplet-based microfluidics which carriers the hydrogel precursor in discrete manners allows the high-throughput production of monodisperse modular microstructures variable in size, shape, and composition. [24] Microfluidics Fabrication of Soft Microtissues and the Bottom-Up AssemblyMicrotissues are cell-laden solid microstructures gelled from hydrogel precursor solutions, adopting and maintaining identical shapes before and after gelation. Normally, cells are loaded into Soft microtissues comprising living cells and supportive matrices have attracted the attention of researchers for their potential as in vitro organ models that represent the patient's tissue heterogeneity, as well as building blocks for artificial organs or regenerative tissues. Microfluidics is known for its capability to produce monodisperse microstructures in high-throughput. This review summarizes the progress on microfluidics fabrication of hydrogel-based microstructures and soft microtissues, and the challenges faced by this field. It mainly focuses on the strengths and limitations of microfluidics fabrication of ex...

show abstract

Flow-induced gelation of microfiber suspensions

Cited by 57 publications

References 70 publications

3D Bioprinting of Macroporous Materials Based on Entangled Hydrogel Microstrands

3D Bioprinting of Macroporous Materials Based on Entangled Hydrogel Microstrands

Structure-Property Relationships via Recovery Rheology in Viscoelastic Materials

Microfluidics Fabrication of Soft Microtissues and Bottom‐Up Assembly

Contact Info

Product

Resources

About