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Rheological characterization of an injectable alginate gel system.

Larsen BE, Bjørnstad J, Pettersen EO, Tønnesen HH, Melvik JE - BMC Biotechnol. (2015)

Bottom Line: By mixing the two components and varying the parameters mentioned above, alginate gel matrices with tailor-made viscoelastic properties and gelling kinetics were obtained.Final gel elasticity depended on alginate type, concentration and gelling ion.Formulations of the injectable and moldable alginate system presented have recently been used within specific medical applications and may have potential within regenerative medicine or other fields.

View Article: PubMed Central - PubMed

Affiliation: School of Pharmacy, University of Oslo, Oslo, Norway. benjamil@gmail.com.

ABSTRACT

Background: This work investigates a general method for producing alginate gel matrices using an internal mode of gelation that depends solely on soluble alginate and alginate/gelling ion particles. The method involves the formulation of two-component kits comprised of soluble alginate and insoluble alginate/gelling ion particles. Gelling kinetics, elastic and Young's moduli were investigated for selected parameters with regard to soluble alginate guluronate content, molecular weight, calcium or strontium gelling ions and alginate gelling ion particle sizes in the range between 25 and 125 micrometers.

Results: By mixing the two components and varying the parameters mentioned above, alginate gel matrices with tailor-made viscoelastic properties and gelling kinetics were obtained. Final gel elasticity depended on alginate type, concentration and gelling ion. The gelling rate could be manipulated, e.g. through selection of the alginate type and molecular weight, particle sizes and the concentration of non-gelling ions.

Conclusions: Formulations of the injectable and moldable alginate system presented have recently been used within specific medical applications and may have potential within regenerative medicine or other fields.

No MeSH data available.


Related in: MedlinePlus

Schematic illustration of the two-component alginate system and the method of gel formation. The system consists of an aqueous sodium alginate solution (A), and insoluble strontium or calcium alginate particles dispersed in an aqueous medium (B). The individual components reside in each of two syringes connected with a three-way connector (C). Upon mixing, gelling ions migrate from the strontium or calcium alginate particles (D). A reciprocal migration of non-gelling ions associated with the soluble alginate also takes place. The gelling ions coordinate with binding sites on two adjacent chains (E) and a gel is formed.
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Fig1: Schematic illustration of the two-component alginate system and the method of gel formation. The system consists of an aqueous sodium alginate solution (A), and insoluble strontium or calcium alginate particles dispersed in an aqueous medium (B). The individual components reside in each of two syringes connected with a three-way connector (C). Upon mixing, gelling ions migrate from the strontium or calcium alginate particles (D). A reciprocal migration of non-gelling ions associated with the soluble alginate also takes place. The gelling ions coordinate with binding sites on two adjacent chains (E) and a gel is formed.

Mentions: The gel system studied (Figure 1) allowed variation of several parameters including the guluronate fraction of the soluble alginate, molecular weight and concentrations of the formulation constituents. A detailed description of the alginate components used can be found in Table 1. The alginate particle dispersion could be modified with respect to particle size and gelling ion species. Mixing the components using the two connected syringes took less than 5 seconds, and after the viscous gelling mass was ejected onto the serrated holding plate of the rheometer the first measurement could be recorded within about 90 seconds. In Figure 2B the development of storage moduli over time is shown for high-guluronate strontium alginate particle dispersions in combination with two different sodium alginate solutions. The sodium alginates had similar molecular weight, but differed in their composition with respect to the guluronic to mannuronic acid ratio. Formulations made using the same sodium alginates and a dispersion of high-mannuronate calcium alginate particles were also investigated (Figure 2A). Storage modulus, G’, as a function of time is shown for both alginates, while loss modulus, G”, and phase angle i.e. arctan(G”/G’), are shown only for the high guluronate alginate, in order to increase the legibility of the figure as it showed a similar tendency.Figure 1


Rheological characterization of an injectable alginate gel system.

Larsen BE, Bjørnstad J, Pettersen EO, Tønnesen HH, Melvik JE - BMC Biotechnol. (2015)

Schematic illustration of the two-component alginate system and the method of gel formation. The system consists of an aqueous sodium alginate solution (A), and insoluble strontium or calcium alginate particles dispersed in an aqueous medium (B). The individual components reside in each of two syringes connected with a three-way connector (C). Upon mixing, gelling ions migrate from the strontium or calcium alginate particles (D). A reciprocal migration of non-gelling ions associated with the soluble alginate also takes place. The gelling ions coordinate with binding sites on two adjacent chains (E) and a gel is formed.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4419456&req=5

Fig1: Schematic illustration of the two-component alginate system and the method of gel formation. The system consists of an aqueous sodium alginate solution (A), and insoluble strontium or calcium alginate particles dispersed in an aqueous medium (B). The individual components reside in each of two syringes connected with a three-way connector (C). Upon mixing, gelling ions migrate from the strontium or calcium alginate particles (D). A reciprocal migration of non-gelling ions associated with the soluble alginate also takes place. The gelling ions coordinate with binding sites on two adjacent chains (E) and a gel is formed.
Mentions: The gel system studied (Figure 1) allowed variation of several parameters including the guluronate fraction of the soluble alginate, molecular weight and concentrations of the formulation constituents. A detailed description of the alginate components used can be found in Table 1. The alginate particle dispersion could be modified with respect to particle size and gelling ion species. Mixing the components using the two connected syringes took less than 5 seconds, and after the viscous gelling mass was ejected onto the serrated holding plate of the rheometer the first measurement could be recorded within about 90 seconds. In Figure 2B the development of storage moduli over time is shown for high-guluronate strontium alginate particle dispersions in combination with two different sodium alginate solutions. The sodium alginates had similar molecular weight, but differed in their composition with respect to the guluronic to mannuronic acid ratio. Formulations made using the same sodium alginates and a dispersion of high-mannuronate calcium alginate particles were also investigated (Figure 2A). Storage modulus, G’, as a function of time is shown for both alginates, while loss modulus, G”, and phase angle i.e. arctan(G”/G’), are shown only for the high guluronate alginate, in order to increase the legibility of the figure as it showed a similar tendency.Figure 1

Bottom Line: By mixing the two components and varying the parameters mentioned above, alginate gel matrices with tailor-made viscoelastic properties and gelling kinetics were obtained.Final gel elasticity depended on alginate type, concentration and gelling ion.Formulations of the injectable and moldable alginate system presented have recently been used within specific medical applications and may have potential within regenerative medicine or other fields.

View Article: PubMed Central - PubMed

Affiliation: School of Pharmacy, University of Oslo, Oslo, Norway. benjamil@gmail.com.

ABSTRACT

Background: This work investigates a general method for producing alginate gel matrices using an internal mode of gelation that depends solely on soluble alginate and alginate/gelling ion particles. The method involves the formulation of two-component kits comprised of soluble alginate and insoluble alginate/gelling ion particles. Gelling kinetics, elastic and Young's moduli were investigated for selected parameters with regard to soluble alginate guluronate content, molecular weight, calcium or strontium gelling ions and alginate gelling ion particle sizes in the range between 25 and 125 micrometers.

Results: By mixing the two components and varying the parameters mentioned above, alginate gel matrices with tailor-made viscoelastic properties and gelling kinetics were obtained. Final gel elasticity depended on alginate type, concentration and gelling ion. The gelling rate could be manipulated, e.g. through selection of the alginate type and molecular weight, particle sizes and the concentration of non-gelling ions.

Conclusions: Formulations of the injectable and moldable alginate system presented have recently been used within specific medical applications and may have potential within regenerative medicine or other fields.

No MeSH data available.


Related in: MedlinePlus