Rheological behavior of alginate solutions for biomanufacturing

Rezende, Rodrigo Alvarenga; Bartolo, Paulo Jorge Da Silva; Mendes, Ausenda; Filho, Rubens Maciel

doi:10.1002/app.30170

Cited by 96 publications

(62 citation statements)

References 23 publications

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“…2, the apparent viscosities of all the alginate solutions decrease with increasing shear stress, demonstrating the shear-thinning nature of alginate solutions at these concentrations. It is consistent with previous observations of shear-thinning behavior of solutions of sodium alginate at these concentrations (19,21,29,31). It is evident from Fig.…”

Section: Steady Shearsupporting

confidence: 93%

“…Although a number of studies have been published on the rheological behavior of sodium alginate solutions (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29), most of the sodium alginates employed in these studies were not pharmaceutical-grade. In addition, these studies were limited to the rheological characterization of sodium alginate solutions at concentrations lower than 5% w/v.…”

Section: Introductionmentioning

confidence: 99%

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Rheological Evaluation of Inter-grade and Inter-batch Variability of Sodium Alginate

et al. 2010

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Abstract. Polymeric excipients are often the least well-characterized components of pharmaceutical formulations. The aim of this study was to facilitate the QbD approach to pharmaceutical manufacturing by evaluating the inter-grade and inter-batch variability of pharmaceutical-grade polymeric excipients. Sodium alginate, a widely used polymeric excipient, was selected for evaluation using appropriate rheological methods and test conditions. The materials used were six different grades of sodium alginate and an additional ten batches of one of the grades. To compare the six grades, steady shear measurements were conducted on solutions at 1%, 2%, and 3% w/w, consistent with their use as thickening agents. Small-amplitude oscillation (SAO) measurements were conducted on sodium alginate solutions at higher concentrations (4-12% w/w) corresponding to their use in controlled-release matrices. In order to compare the ten batches of one grade, steady shear and SAO measurements were performed on their solutions at 2% w/w and 8% w/w, respectively. Results show that the potential interchangeability of these different grades used as thickening agents could be established by comparing the apparent viscosities of their solutions as a function of both alginate concentration and shear conditions. For sodium alginate used in controlled-release formulations, both steady shear behavior of solutions at low concentrations and viscoelastic properties at higher concentrations should be considered. Furthermore, among batches of the same grade, significant differences in rheological properties were observed, especially at higher solution concentrations. In conclusion, inter-grade and inter-batch variability of sodium alginate can be determined using steady shear and small-amplitude oscillation methods.

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Section: Steady Shearsupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Rheological Evaluation of Inter-grade and Inter-batch Variability of Sodium Alginate

et al. 2010

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“…However, for our system the best results were obtained in the same range of viscosity (of about 1 up to several Pas) as was previously reported for another biomaterial which was used as a bioink, namely sodium alginate. 35 Even so 2 or 3% alginate solutions (with 0.9 or 2.0 Pas viscosity, respectively) can be printed, the spatial resolution and form stability of the strands and struts as well as the overall shape of a printed construct is far from being optimal. Having a sufficiently high viscosity is important for bioprinting, as it prevents surface tension-driven droplet formation at the nozzle tip, as well as collapse of the plotted structure.…”

mentioning

confidence: 99%

Development and characterisation of a new bioink for additive tissue manufacturing

et al. 2014

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Additive manufacturing forms a potential route towards economically viable production of cellular constructs for tissue engineering. Hydrogels are a suitable class of materials for cell delivery and 3D culture, but are generally unsuitable as construction materials. Gelatine-methacrylamide is an example of such a hydrogel system widely used in the field of tissue engineering, e.g. for cartilage and cardiovascular applications. Here we show that by the addition of gellan gum to gelatinemethacrylamide and tailoring salt concentrations, rheological properties such as pseudo-plasticity and yield stress can be optimised towards gel dispensing for additive manufacturing processes. In the hydrogel formulation, salt is partly substituted by mannose to obtain isotonicity and prevent a reduction in cell viability. With this, the potential of this new bioink for additive tissue manufacturing purposes is demonstrated.

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“…Concentrated, entangled solutions of alginate, however, exhibit shear-thinning behaviour. This effect is shown by Rezende et al (2009), where apparent viscosity is reduced in various alginate concentrations on increasing rate of deformation. Like most polysaccharides, the viscosity of concentrated alginate solutions is highly dependent upon the molecular weight, with viscosity increasing with increased molecular weight.…”

Section: Alginate Solutionsmentioning

confidence: 90%