The sol–gel transition of ultra-low solid content TEMPO-cellulose nanofibril/mixed-linkage β-glucan bionanocomposite gels

Arola, Suvi; Ansari, Mahmoud; Oksanen, Antti; Retulainen, Elias; Hatzikiriakos, Savvas G.; Brumer, Harry

doi:10.1039/c8sm01878b

Cited by 15 publications

(19 citation statements)

References 67 publications

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“…For these reasons, CMNF suspensions can form yield-stress gels already at approx. 0.1-0.3% consistency (Varanasi et al 2013;Raj et al 2016;Li et al 2016;Arola et al 2018), and they have a strong tendency towards aggregation and flocculation (Karppinen et al 2012;Pääkkönen et al 2016;Hubbe et al 2017;Raj et al 2017;. Notice that highly crystalline and rigid nanoparticles having a length of a few hundred nanometers can be obtained from cellulose e.g.…”

Section: Introductionmentioning

confidence: 99%

The effect of consistency on the shear rheology of aqueous suspensions of cellulose micro- and nanofibrils: a review

Koponen

2019

Cellulose

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While the raw material type and the production method of cellulose micro- and nanofibrils (CMNFs) strongly affect the absolute values of the rheological parameters of their aqueous suspensions, the dependence of these parameters on consistency, c, is found to be uniform. The consistency index and yield stress of CMNF suspensions follow generally the scaling laws $$K \sim c^{2.43}$$K∼c2.43 and $$\tau_{y} \sim c^{2.26}$$τy∼c2.26, respectively, and a decent approximation for flow index is $$n = 0.30 \times c^{ - 0.43}$$n=0.30×c-0.43. The variability of reported scaling exponents of these materials is likely mainly due to experimental uncertainties and not so much due to fundamentally different rheology. It is suggested that the reason behind the apparently universal rheological behavior of CMNF suspensions is the strong entanglement of fibrils; the flow dynamics of typical CMNF suspensions is dominated by interactions between fibril flocs and not by interactions between individual fibrils. Graphic abstract

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Section: Introductionmentioning

confidence: 99%

The effect of consistency on the shear rheology of aqueous suspensions of cellulose micro- and nanofibrils: a review

Koponen

2019

Cellulose

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“…SA has been found to effectively coat capsules containing pancreatic β cells at a thickness that allows for the same insulin release profile as un-encapsulated cells [ 36 ]. Consistently, SA has been found to not stimulate the immune system, whilst allowing for appropriate glycaemic response in β cells in animal models [ 38 , 39 , 41 , 42 ]. Generally, SA is effective in the short-term protection of β cells but, eventually, inflammation and lack of engraftment lead to failure of the cells [ 37 , 41 ].…”

Section: Introductionmentioning

confidence: 97%

“…Ultra-soluble gels (USG) are non-petroleum based biological polymers that can be integrated into capsules to modify their physical properties [ 13 , 14 , 15 , 16 , 42 , 43 , 44 ]. They provide a suitably biocompatible microenvironment and are a relatively cheap way to vary properties of the capsules including their strength and consistency [ 42 , 43 ]. The type and proportion of the USG are the primary parameters used to vary these physical properties of the capsules [ 42 , 43 ].…”

Section: Introductionmentioning

confidence: 99%

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Enhanced Bilosomal Properties Resulted in Optimum Pharmacological Effects by Increased Acidification Pathways

et al. 2021

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Introduction: Recent studies in our laboratory have shown that some bile acids, such as chenodeoxycholic acid (CDCA), can exert cellular protective effects when encapsulated with viable β-cells via anti-inflammatory and anti-oxidative stress mechanisms. However, to explore their full potential, formulating such bile acids (that are intrinsically lipophilic) can be challenging, particularly if larger doses are required for optimal pharmacological effects. One promising approach is the development of nano gels. Accordingly, this study aimed to examine biological effects of various concentrations of CDCA using various solubilising nano gel systems on encapsulated β-cells. Methods: Using our established cellular encapsulation system, the Ionic Gelation Vibrational Jet Flow technology, a wide range of CDCA β-cell capsules were produced and examined for morphological, biological, and inflammatory profiles. Results and Conclusion: Capsules’ morphology and topographic characteristics remained similar, regardless of CDCA or nano gel concentrations. The best pharmacological, anti-inflammatory, and cellular respiration, metabolism, and energy production effects were observed at high CDCA and nano gel concentrations, suggesting dose-dependent cellular protective and positive effects of CDCA when incorporated with high loading nano gel.

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“…For example, 2,2,6,6-tetramethyl-piperidin-1-yl)oxyl (TEMPO) mediated oxidation is commonly used to introduce negatively charged carboxyl groups to the cellulose surface, which is key to enhance the stability of particle dispersions in aqueous media due to electrostatic repulsion forces [4,5]. Cellulose nanofibrils have been extensively used to form hydrogels where the properties can be modulated by various factors such as salts [6,7], pH [8,9], concentration [10,11], temperature [12], and surfactants [13][14][15]. In addition, OCNF hydrogels have been reported to have excellent shear-thinning properties, which is desirable for 2 of 17 some formulation-based products, especially in health and personal care applications [13].…”

Section: Introductionmentioning

confidence: 99%

Monovalent Salt and pH-Induced Gelation of Oxidised Cellulose Nanofibrils and Starch Networks: Combining Rheology and Small-Angle X-ray Scattering

et al. 2021

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Water quality parameters such as salt content and various pH environments can alter the stability of gels as well as their rheological properties. Here, we investigated the effect of various concentrations of NaCl and different pH environments on the rheological properties of TEMPO-oxidised cellulose nanofibril (OCNF) and starch-based hydrogels. Addition of NaCl caused an increased stiffness of the OCNF:starch (1:1 wt%) blend gels, where salt played an important role in reducing the repulsive OCNF fibrillar interactions. The rheological properties of these hydrogels were unchanged at pH 5.0 to 9.0. However, at lower pH (4.0), the stiffness and viscosity of the OCNF and OCNF:starch gels appeared to increase due to proton-induced fibrillar interactions. In contrast, at higher pH (11.5), syneresis was observed due to the formation of denser and aggregated gel networks. Interactions as well as aggregation behaviour of these hydrogels were explored via ζ-potential measurements. Furthermore, the nanostructure of the OCNF gels was probed using small-angle x-ray scattering (SAXS), where the SAXS patterns showed an increase of slope in the low-q region with increasing salt concentration arising from aggregation due to the screening of the surface charge of the fibrils.

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The sol–gel transition of ultra-low solid content TEMPO-cellulose nanofibril/mixed-linkage β-glucan bionanocomposite gels

Abstract: Ultra-low solid content gels were prepared by physically cross-linking TEMPO-oxidized cellulose nanofibrils (TEMPO-CNF) with the plant-cell-wall polysaccharide, mixed-linkage β-glucan (MLG).

Cited by 15 publications

References 67 publications

The effect of consistency on the shear rheology of aqueous suspensions of cellulose micro- and nanofibrils: a review

The effect of consistency on the shear rheology of aqueous suspensions of cellulose micro- and nanofibrils: a review

Enhanced Bilosomal Properties Resulted in Optimum Pharmacological Effects by Increased Acidification Pathways

Monovalent Salt and pH-Induced Gelation of Oxidised Cellulose Nanofibrils and Starch Networks: Combining Rheology and Small-Angle X-ray Scattering

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