Le pubblicazioni dei componenti del gruppo di ricerca.
2016
Caccavo, Diego; Ström, Anna; Larsson, Anette; Lamberti, Gaetano
Modeling capillary formation in calcium and copper alginate gels Journal Article
In: Materials Science and Engineering: C, vol. 58, pp. 442–449, 2016, ISSN: 09284931.
Abstract | Links | BibTeX | Tags: Alginate, Gel capillaries, Hydrogel Characterization, Hydrogel Modeling, Ionotropic gelation, Modeling
@article{Caccavo2016,
title = {Modeling capillary formation in calcium and copper alginate gels},
author = { Diego Caccavo and Anna Str\"{o}m and Anette Larsson and Gaetano Lamberti},
url = {http://www.sciencedirect.com/science/article/pii/S0928493115302940},
doi = {10.1016/j.msec.2015.08.040},
issn = {09284931},
year = {2016},
date = {2016-01-01},
journal = {Materials Science and Engineering: C},
volume = {58},
pages = {442--449},
abstract = {Alginate solutions in the presence of bivalent ions can form ionic cross-linked gels. In particular gelation conditions the gel structure can be characterized by great anisotropy with the presence of straight capillaries along a preferential direction. These materials can find applications mainly in high-tech sectors, like tissue engineering, where the gel characteristics play a crucial role. Despite the need of mastering the capillary formation and properties, the process remains a poorly known problem, and its development is left to trial and error procedures. In this work a quantitative approach to the description of the capillary formation process has been developed. The theory proposed by Treml et al. (2003) has been implemented and extended to an alginate different from the one used in that study and two different ions (calcium and copper). Some of the model parameters have been derived through simple measurements; others have been scaled using proper scaling equations. Experiments have been performed in different gelation conditions, varying alginate and ionic solution concentrations, to highlight the effects of these parameters on the anisotropic structure and to validate the model. In all the analyses done, the model has performed nicely showing a good reliability in the prediction of gel characteristics like capillary formation, capillary length and process time.},
keywords = {Alginate, Gel capillaries, Hydrogel Characterization, Hydrogel Modeling, Ionotropic gelation, Modeling},
pubstate = {published},
tppubtype = {article}
}
Alginate solutions in the presence of bivalent ions can form ionic cross-linked gels. In particular gelation conditions the gel structure can be characterized by great anisotropy with the presence of straight capillaries along a preferential direction. These materials can find applications mainly in high-tech sectors, like tissue engineering, where the gel characteristics play a crucial role. Despite the need of mastering the capillary formation and properties, the process remains a poorly known problem, and its development is left to trial and error procedures. In this work a quantitative approach to the description of the capillary formation process has been developed. The theory proposed by Treml et al. (2003) has been implemented and extended to an alginate different from the one used in that study and two different ions (calcium and copper). Some of the model parameters have been derived through simple measurements; others have been scaled using proper scaling equations. Experiments have been performed in different gelation conditions, varying alginate and ionic solution concentrations, to highlight the effects of these parameters on the anisotropic structure and to validate the model. In all the analyses done, the model has performed nicely showing a good reliability in the prediction of gel characteristics like capillary formation, capillary length and process time.
2013
Schuster, Erich; Caccavo, Diego; Eckardt, Johanna; Altskär, Annika; Hermansson, Anne-Marie; Larsson, Anette; Ström, Anna
Spontaneous formation of parallel aligned macropores within polysaccharide gels Proceedings Article
In: Materials for Tomorrow, 2013.
Abstract | BibTeX | Tags: Alginate
@inproceedings{Schuster2013,
title = {Spontaneous formation of parallel aligned macropores within polysaccharide gels},
author = {Erich Schuster and Diego Caccavo and Johanna Eckardt and Annika Altsk\"{a}r and Anne-Marie Hermansson and Anette Larsson and Anna Str\"{o}m},
year = {2013},
date = {2013-10-02},
booktitle = {Materials for Tomorrow},
abstract = {The ability to control and direct mass transport of fluids and molecular components through soft biomaterials is of importance in a wide range of applications. Alginate is a biocompatible, renewable polymer source extracted from seaweed. The readily available anionic polysaccharide find commercial use in diverse areas such as wound care, pharmaceutics and food. Alginate forms a gel by rapid crosslinking with di- and tri-valent ions [1]. In this work we have used two different ways to introduce the multivalent ions that act as ion bridges between alginate. The methods are the "internal setting" [1] of the gels giving macroscopically homogeneous gels and “directed external” gelation [2] of the alginate giving rise to anisotropic growth of open capillaries running through the gel, see Figure 1.
Our aim was to relate microstructural differences in the gels prepared by different methodologies to mass transport properties, and to determine the effect of various ions on the formation of channels.
Although the same amount of calcium ions was present the porous calcium alginate gel had a local diffusion significantly higher compared to the corresponding gel without capillaries. The diameter and amount of capillaries could be tailored by using different types of ions from tenth to several hundreds of micrometers. By varying the preparation method and the type of ion for gelation we are able to form a biomaterial with different mass transport properties according to our needs. },
keywords = {Alginate},
pubstate = {published},
tppubtype = {inproceedings}
}
The ability to control and direct mass transport of fluids and molecular components through soft biomaterials is of importance in a wide range of applications. Alginate is a biocompatible, renewable polymer source extracted from seaweed. The readily available anionic polysaccharide find commercial use in diverse areas such as wound care, pharmaceutics and food. Alginate forms a gel by rapid crosslinking with di- and tri-valent ions [1]. In this work we have used two different ways to introduce the multivalent ions that act as ion bridges between alginate. The methods are the "internal setting" [1] of the gels giving macroscopically homogeneous gels and “directed external” gelation [2] of the alginate giving rise to anisotropic growth of open capillaries running through the gel, see Figure 1.
Our aim was to relate microstructural differences in the gels prepared by different methodologies to mass transport properties, and to determine the effect of various ions on the formation of channels.
Although the same amount of calcium ions was present the porous calcium alginate gel had a local diffusion significantly higher compared to the corresponding gel without capillaries. The diameter and amount of capillaries could be tailored by using different types of ions from tenth to several hundreds of micrometers. By varying the preparation method and the type of ion for gelation we are able to form a biomaterial with different mass transport properties according to our needs.
Our aim was to relate microstructural differences in the gels prepared by different methodologies to mass transport properties, and to determine the effect of various ions on the formation of channels.
Although the same amount of calcium ions was present the porous calcium alginate gel had a local diffusion significantly higher compared to the corresponding gel without capillaries. The diameter and amount of capillaries could be tailored by using different types of ions from tenth to several hundreds of micrometers. By varying the preparation method and the type of ion for gelation we are able to form a biomaterial with different mass transport properties according to our needs.
Schuster, Erich; Caccavo, Diego; Eckardt, Johanna; Altskär, Annika; Hermansson, Anne-Marie; Larsson, Anette; Ström, Anna
Microstructural, mechanical and mass transport properties of alginate capillary gels Proceedings Article
In: International Symposium on the Properties of Water, Fiskebäckskil, Sweden, 2013.
@inproceedings{Schuster2013b,
title = {Microstructural, mechanical and mass transport properties of alginate capillary gels},
author = {Erich Schuster and Diego Caccavo and Johanna Eckardt and Annika Altsk\"{a}r and Anne-Marie Hermansson and Anette Larsson and Anna Str\"{o}m},
year = {2013},
date = {2013-08-20},
booktitle = {International Symposium on the Properties of Water},
address = {Fiskeb\"{a}ckskil, Sweden},
keywords = {Alginate},
pubstate = {published},
tppubtype = {inproceedings}
}