Shear Sensitivity

Chisti, Yusuf

doi:10.1002/0471250589.ebt198

Cited by 32 publications

(49 citation statements)

References 120 publications

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“…Microbial morphology is well-known to influence susceptibility to shear damage [13]. Conceivably, therefore, it may be possible to culture the polymorphic diatom P. tricornutum in morphtypes with improved ability to withstand damage causing forces.…”

Section: Resultsmentioning

confidence: 99%

“…Mechanical agitation is known to enhance radial mixing. Unfortunately, mechanical agitation can be detrimental to algal cells [12][13][14][15][16]. Consequently, shearsensitivity of cultures can severely restrict the attainable productivity in bioreactors.…”

Section: Introductionmentioning

confidence: 99%

“…Damage to microalgae and cyanobacteria under processing conditions can be a real problem [6,[13][14][15][18][19][20], but susceptibility to damage is dependent on the species. Algae such as Dunaliella are extremely fragile [18,19], but many other species will tolerate high levels of turbulence and sparging with gas.…”

Section: Introductionmentioning

confidence: 99%

“…Increasing shear damage with increasing culture viscosity has been reported for the protozoan Tetrahymena pyriformis [30] and for red blood cells [31]. These seemingly contradictory results are easily explained: whether changes in viscosity increase or reduce shear damage depends on the peculiarities of the mechanism causing the damage [13,32]. For a given impeller tip speed, increasing viscosity will not affect the tip speed-associated shear rate, but the turbulence will be reduced; hence, the shear rate in the fluid should be lower.…”

Section: Introductionmentioning

confidence: 99%

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Effects of agitation on the microalgae Phaeodactylum tricornutum and Porphyridium cruentum

Sobczuk

Camacho

Grima

et al. 2005

Bioprocess Biosyst Eng

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134

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The effect of mechanical agitation on the microalgae Phaeodactylum tricornutum and Porphyridium cruentum was investigated in aerated continuous cultures with and without the added shear protectant Pluronic F68. Damage to cells was quantified through a decrease in the steady state concentration of the biomass in the photobioreactor. For a given aeration rate, the steady state biomass concentration rose with increasing rate of mechanical agitation until an upper limit on agitation speed was reached. This maximum tolerable agitation speed depended on the microalgal species. Further increase in agitation speed caused a decline in the steady state concentration of the biomass. An impeller tip speed of >1.56 m s(-1) damaged P. tricornutum in aerated culture. In contrast, the damage threshold tip speed for P. cruentum was between 2.45 and 2.89 m s(-1). Mechanical agitation was not the direct cause of cell damage. Damage occurred because of the rupture of small gas bubbles at the surface of the culture, but mechanical agitation was instrumental in generating the bubbles that ultimately damaged the cells. Pluronic F68 protected the cells against damage and increased the steady state concentration of the biomass relative to operation without the additive. The protective effect of Pluronic was concentration-dependent over the concentration range of 0.01-0.10% w/v.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of agitation on the microalgae Phaeodactylum tricornutum and Porphyridium cruentum

Sobczuk

Camacho

Grima

et al. 2005

Bioprocess Biosyst Eng

Self Cite

134

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“…A fermentation is infl uenced by numerous factors, including temperature, pH, ionic strength, nature and composition of the medium, dissolved oxygen, dissolved carbon dioxide, and shear rates [5] in the fermenter. The method of operation (e.g., batch, fed -batch, continuous, precursor feeding) and mixing (cycling through varying environments) also infl uence fermentations [2] .…”

Section: Environmental Factorsmentioning

confidence: 99%

Fermentation Technology

Chisti¹

2010

Industrial Biotechnology

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Cytoprotection of Human Progenitor and Stem Cells through Encapsulation in Alginate Templated, Dual Crosslinked Silk and Silk–Gelatin Composite Hydrogel Microbeads

Hasturk

Smiley

Arnett

et al. 2022

Adv Healthcare Materials

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Susceptibility of mammalian cells against harsh processing conditions limit their use in cell transplantation and tissue engineering applications. Besides modulation of the cell microenvironment, encapsulation of mammalian cells within hydrogel microbeads attract attention for cytoprotection through physical isolation of the encapsulated cells. The hydrogel formulations used for cell microencapsulation are largely dominated by ionically crosslinked alginate (Alg), which suffer from low structural stability under physiological culture conditions and poor cell–matrix interactions. Here the fabrication of Alg templated silk and silk/gelatin composite hydrogel microspheres with permanent or on‐demand cleavable enzymatic crosslinks using simple and cost‐effective centrifugation‐based droplet processing are demonstrated. The composite microbeads display structural stability under ion exchange conditions with improved mechanical properties compared to ionically crosslinked Alg microspheres. Human mesenchymal stem and neural progenitor cells are successfully encapsulated in the composite beads and protected against environmental factors, including exposure to polycations, extracellular acidosis, apoptotic cytokines, ultraviolet (UV) irradiation, anoikis, immune recognition, and particularly mechanical stress. The microbeads preserve viability, growth, and differentiation of encapsulated stem and progenitor cells after extrusion in viscous polyethylene oxide solution through a 27‐gauge fine needle, suggesting potential applications in injection‐based delivery and three‐dimensional bioprinting of mammalian cells with higher success rates.

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Shear Sensitivity

Cited by 32 publications

References 120 publications

Effects of agitation on the microalgae Phaeodactylum tricornutum and Porphyridium cruentum

Effects of agitation on the microalgae Phaeodactylum tricornutum and Porphyridium cruentum

Fermentation Technology

Cytoprotection of Human Progenitor and Stem Cells through Encapsulation in Alginate Templated, Dual Crosslinked Silk and Silk–Gelatin Composite Hydrogel Microbeads

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