Egg-box model-based gelation of alginate and pectin: A review

Cao, Lianqi; Lü, Wei; Mata, Analucia; Nishinari, Katsuyoshi; Fang, Yapeng

doi:10.1016/j.carbpol.2020.116389

Cited by 416 publications

(259 citation statements)

References 138 publications

Supporting

Mentioning

246

Contrasting

Unclassified

Order By: Relevance

“…A droplet of this mixture is then deposed on the surface of an aqueous CaCl 2 solution (standard: w CaCl2•2H2O = 0.5%). The Ca 2+ ions serve as crosslinker and induce, within several microseconds, the gelation of the alginate membranes according to the box-egg model [43][44][45][46]. Immediately after the formation of these particles, the capsules start to swim along the water surface.…”

Section: Swimmer Synthesis and Characterizationmentioning

confidence: 99%

Surfactant-loaded capsules as Marangoni microswimmers at the air–water interface: Symmetry breaking and spontaneous propulsion by surfactant diffusion and advection

et al. 2021

View full text Add to dashboard Cite

We present a realization of a fast interfacial Marangoni microswimmer by a half-spherical alginate capsule at the air–water interface, which diffusively releases water-soluble spreading molecules (weak surfactants such as polyethylene glycol (PEG)), which act as “fuel” by modulating the air–water interfacial tension. For a number of different fuels, we can observe symmetry breaking and spontaneous propulsion although the alginate particle and emission are isotropic. The propulsion mechanism is similar to soap or camphor boats, which are, however, typically asymmetric in shape or emission to select a swimming direction. We develop a theory of Marangoni boat propulsion starting from low Reynolds numbers by analyzing the coupled problems of surfactant diffusion and advection and fluid flow, which includes surfactant-induced fluid Marangoni flow, and surfactant adsorption at the air–water interface; we also include a possible evaporation of surfactant. The swimming velocity is determined by the balance of drag and Marangoni forces. We show that spontaneous symmetry breaking resulting in propulsion is possible above a critical dimensionless surfactant emission rate (Peclet number). We derive the relation between Peclet number and swimming speed and generalize to higher Reynolds numbers utilizing the concept of the Nusselt number. The theory explains the observed swimming speeds for PEG–alginate capsules, and we unravel the differences to other Marangoni boat systems based on camphor, which are mainly caused by surfactant evaporation from the liquid–air interface. The capsule Marangoni microswimmers also exhibit surfactant-mediated repulsive interactions with walls, which can be qualitatively explained by surfactant accumulation at the wall. Graphic Abstract

show abstract

Section: Swimmer Synthesis and Characterizationmentioning

confidence: 99%

Surfactant-loaded capsules as Marangoni microswimmers at the air–water interface: Symmetry breaking and spontaneous propulsion by surfactant diffusion and advection

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The source of alginate (marine vs. bacterial, place of seaweed collection), the extraction, purification and modification methods determine the content and ratio of (1,4)-linked β-D-mannuronate (M) and its C-5 epimer α-L-guluronate (G) (M/G ratio) and their alternating sequences (MG). Due to their distinguished properties, such as ease of gelling with divalent metal cations (ionic cross-linking) thus forming an "egg-box" structure [5] and 3D environment close to the extracellular matrix of native tissues, high biocompatibility, low immunogenicity in vivo and controlled biodegradability [6][7][8], alginate hydrogels have been widely used in medicine and medicine-related research [3]. This includes delivery vehicles in cancer treatment [9], wound dressing [4], mammalian cell culture in biomedical studies, tissue regeneration with protein and cell delivery, engineering of various tissues/organs [10][11][12] including bladder regeneration [13], bone tissue engineering [14], and a protective carrier for cryopreservation [15].…”

Section: Introductionmentioning

confidence: 99%

Coaxial Alginate Hydrogels: From Self-Assembled 3D Cellular Constructs to Long-Term Storage

Gryshkov

Mutsenko

Tarusin

et al. 2021

IJMS

View full text Add to dashboard Cite

Alginate as a versatile naturally occurring biomaterial has found widespread use in the biomedical field due to its unique features such as biocompatibility and biodegradability. The ability of its semipermeable hydrogels to provide a favourable microenvironment for clinically relevant cells made alginate encapsulation a leading technology for immunoisolation, 3D culture, cryopreservation as well as cell and drug delivery. The aim of this work is the evaluation of structural properties and swelling behaviour of the core-shell capsules for the encapsulation of multipotent stromal cells (MSCs), their 3D culture and cryopreservation using slow freezing. The cells were encapsulated in core-shell capsules using coaxial electrospraying, cultured for 35 days and cryopreserved. Cell viability, metabolic activity and cell–cell interactions were analysed. Cryopreservation of MSCs-laden core-shell capsules was performed according to parameters pre-selected on cell-free capsules. The results suggest that core-shell capsules produced from the low viscosity high-G alginate are superior to high-M ones in terms of stability during in vitro culture, as well as to solid beads in terms of promoting formation of viable self-assembled cellular structures and maintenance of MSCs functionality on a long-term basis. The application of 0.3 M sucrose demonstrated a beneficial effect on the integrity of capsules and viability of formed 3D cell assemblies, as compared to 10% dimethyl sulfoxide (DMSO) alone. The proposed workflow from the preparation of core-shell capsules with self-assembled cellular structures to the cryopreservation appears to be a promising strategy for their off-the-shelf availability.

show abstract

“…Despite the “egg‐box model” has been used to describe the main mechanism of Ca 2+ ‐mediated gelation of both alginate and pectin, critical differences in their chemical structures have been linked to significant alterations in chain‐chain associations and consequently on the final gel properties. [ 25 ] As a result, a modified “shifted egg‐box model” was proposed to explain the gelation mechanism of pectin based on the fact that two antiparallel pectin chains exhibit a more pronounced shift of 1.7 Å (0.6 Å higher than that of alginate) with functional consequences, including the reduction of the original large cavity to provide two symmetrical sub‐cavities of appropriate size for binding a calcium ion. [ 26 ] This fact, together with the differences reported in the ionic radii between the calcium and barium ions (Ba 2+ : 1.49 Å; Ca 2+ : 1.14 Å), the branched pectin network chain structure and the presence of methoxylated carboxyl groups in some galacturonic acid units [ 21 ] can contribute to altered ion‐binding affinity.…”

Section: Resultsmentioning

confidence: 99%

Bioprinting a Multifunctional Bioink to Engineer Clickable 3D Cellular Niches with Tunable Matrix Microenvironmental Cues

Pereira

Lourenço

Bártolo

et al. 2020

Adv Healthcare Materials

View full text Add to dashboard Cite

The properties of the surrounding cell environment are major determinants of cell response in 3D. However, the ability to unravel how these cues dictate the biological function in bioprinted constructs is limited by the lack of extracellular matrix (ECM)‐mimetic bioinks with fully controllable properties. In this study, a multifunctional bioink that uniquely combines the independent control over the biochemical and biophysical cues that regulate cell fate with the bioorthogonal nature of thiol–norbornene photoclick chemistry is designed for the extrusion bioprinting of bioinspired 3D cellular niches with tunable properties. The bioink rheology is controlled by ionic gelation, being dependent on both the type and content of divalent ions (calcium and barium), while the mechanical and biochemical properties of hydrogels are tailored via a post printing thiol–ene reaction. Bioprinted cell‐adhesive and protease‐degradable hydrogels modulate cell proliferation and ECM deposition in a matrix‐stiffness dependent manner over 14 days of culture regardless of cell spreading, demonstrating the ability to probe the effect of matrix cues on cell response. This bioink can be used as a versatile platform where building blocks can be rationally combined for the bioprinting of functional cell‐ and tissue‐specific constructs with controlled cellular behavior.

show abstract

Egg-box model-based gelation of alginate and pectin: A review

Cited by 416 publications

References 138 publications

Surfactant-loaded capsules as Marangoni microswimmers at the air–water interface: Symmetry breaking and spontaneous propulsion by surfactant diffusion and advection

Surfactant-loaded capsules as Marangoni microswimmers at the air–water interface: Symmetry breaking and spontaneous propulsion by surfactant diffusion and advection

Coaxial Alginate Hydrogels: From Self-Assembled 3D Cellular Constructs to Long-Term Storage

Bioprinting a Multifunctional Bioink to Engineer Clickable 3D Cellular Niches with Tunable Matrix Microenvironmental Cues

Contact Info

Product

Resources

About