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Chitosan as a Biomaterial: Influence of Degree of Deacetylation on Its Physiochemical, Material and Biological Properties.

Foster LJ, Ho S, Hook J, Basuki M, Marçal H - PLoS ONE (2015)

Bottom Line: Apoptotic indices and cell cycle analysis also suggested that chitosan films with DDAs below 75% were cytocompatible but induced cellular stress, while OECs grown on films fabricated from chitosan with DDAs above 75% showed no significant differences compared to those in asynchronous growth.NMR examination of the chitosan samples here revealed significant differences depending upon which peaks were selected for integration; 6 to 13% in DDA values within individual samples.Furthermore, differences between DDA values determined here and those reported by the commercial suppliers were significant and this may also be a source of concern when selecting commercial chitosans for biomaterial research.

View Article: PubMed Central - PubMed

Affiliation: Bio/Polymer Research Group, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia.

ABSTRACT
Chitosan is a biomaterial with a range of current and potential biomedical applications. Manipulation of chitosan degree of deacetylation (DDA) to achieve specific properties appears feasible, but studies investigating its influence on properties are often contradictory. With a view to the potential of chitosan in the regeneration of nerve tissue, the influence of DDA on the growth and health of olfactory ensheathing cells (OECs) was investigated. There was a linear increase in OEC proliferation as the DDA increased from 72 to 85%. This correlated with linear increases in average surface roughness (0.62 to 0.78 μm) and crystallinity (4.3 to 10.1%) of the chitosan films. Mitochondrial activity and membrane integrity of OECs was significantly different for OECs cultivated on chitosan with DDAs below 75%, while those on films with DDAs up to 85% were similar to cells in asynchronous growth. Apoptotic indices and cell cycle analysis also suggested that chitosan films with DDAs below 75% were cytocompatible but induced cellular stress, while OECs grown on films fabricated from chitosan with DDAs above 75% showed no significant differences compared to those in asynchronous growth. Tensile strength and elongation to break varied with DDA from 32.3 to 45.3 MPa and 3.6 to 7.1% respectively. DDA had no significant influence on abiotic and biotic degradation profiles of the chitosan films which showed approximately 8 and 20% weight loss respectively. Finally, perceived patterns in property changes are subject to change based on potential variations in DDA analysis. NMR examination of the chitosan samples here revealed significant differences depending upon which peaks were selected for integration; 6 to 13% in DDA values within individual samples. Furthermore, differences between DDA values determined here and those reported by the commercial suppliers were significant and this may also be a source of concern when selecting commercial chitosans for biomaterial research.

No MeSH data available.


Related in: MedlinePlus

Variation in surface microtopograpies of solvent cast films fabricated from commercial chitosan samples with different DDAs as determined by (a) average surface roughness (Ra) and (b) microwaviness.
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pone.0135153.g015: Variation in surface microtopograpies of solvent cast films fabricated from commercial chitosan samples with different DDAs as determined by (a) average surface roughness (Ra) and (b) microwaviness.

Mentions: Water contact angle measurements, as well as the adhesion and proliferation of both mammalian and microbial cells, are also influenced by surface topography [42,43,21]. Fig 14A shows the microtopography of a film fabrication from chitosan with a DDA of 72% as determined through confocal laser scanning microscopy; little difference can be discerned when compared to a film fabricated from chitosan with a DDA of 85% (Fig 14B). However, quantitative analysis of these depth maps showed significant differences in their average surface roughness, Ra. There was a linear increase in Ra with increasing DDA, from 0.62 ± 0.02 to 0.78 ± 0.02 μm for films fabricated from chitosan with 72 and 85% DDA respectively (Fig 15A). Chung et al. has reported that increases in surface roughness even at 101–102 nm scales can enhance cell adhesion to polymer surfaces [43]. Thus, the trend in surface roughness determined here is consistent with the trend for cell proliferation, suggesting that the rougher surface also supported cell adhesion and proliferation. In contrast, the harmonic component of these films, ‘microwaviness’, showed no significant difference with DDA variation, suggesting no regular arrangement to the microtopographies (P < 0.05, Fig 14B). Furthermore, Clasen et al. has suggested that roughness and porosity can decrease tensile strength due to less stability in the molecular structure [45].


Chitosan as a Biomaterial: Influence of Degree of Deacetylation on Its Physiochemical, Material and Biological Properties.

Foster LJ, Ho S, Hook J, Basuki M, Marçal H - PLoS ONE (2015)

Variation in surface microtopograpies of solvent cast films fabricated from commercial chitosan samples with different DDAs as determined by (a) average surface roughness (Ra) and (b) microwaviness.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4549144&req=5

pone.0135153.g015: Variation in surface microtopograpies of solvent cast films fabricated from commercial chitosan samples with different DDAs as determined by (a) average surface roughness (Ra) and (b) microwaviness.
Mentions: Water contact angle measurements, as well as the adhesion and proliferation of both mammalian and microbial cells, are also influenced by surface topography [42,43,21]. Fig 14A shows the microtopography of a film fabrication from chitosan with a DDA of 72% as determined through confocal laser scanning microscopy; little difference can be discerned when compared to a film fabricated from chitosan with a DDA of 85% (Fig 14B). However, quantitative analysis of these depth maps showed significant differences in their average surface roughness, Ra. There was a linear increase in Ra with increasing DDA, from 0.62 ± 0.02 to 0.78 ± 0.02 μm for films fabricated from chitosan with 72 and 85% DDA respectively (Fig 15A). Chung et al. has reported that increases in surface roughness even at 101–102 nm scales can enhance cell adhesion to polymer surfaces [43]. Thus, the trend in surface roughness determined here is consistent with the trend for cell proliferation, suggesting that the rougher surface also supported cell adhesion and proliferation. In contrast, the harmonic component of these films, ‘microwaviness’, showed no significant difference with DDA variation, suggesting no regular arrangement to the microtopographies (P < 0.05, Fig 14B). Furthermore, Clasen et al. has suggested that roughness and porosity can decrease tensile strength due to less stability in the molecular structure [45].

Bottom Line: Apoptotic indices and cell cycle analysis also suggested that chitosan films with DDAs below 75% were cytocompatible but induced cellular stress, while OECs grown on films fabricated from chitosan with DDAs above 75% showed no significant differences compared to those in asynchronous growth.NMR examination of the chitosan samples here revealed significant differences depending upon which peaks were selected for integration; 6 to 13% in DDA values within individual samples.Furthermore, differences between DDA values determined here and those reported by the commercial suppliers were significant and this may also be a source of concern when selecting commercial chitosans for biomaterial research.

View Article: PubMed Central - PubMed

Affiliation: Bio/Polymer Research Group, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia.

ABSTRACT
Chitosan is a biomaterial with a range of current and potential biomedical applications. Manipulation of chitosan degree of deacetylation (DDA) to achieve specific properties appears feasible, but studies investigating its influence on properties are often contradictory. With a view to the potential of chitosan in the regeneration of nerve tissue, the influence of DDA on the growth and health of olfactory ensheathing cells (OECs) was investigated. There was a linear increase in OEC proliferation as the DDA increased from 72 to 85%. This correlated with linear increases in average surface roughness (0.62 to 0.78 μm) and crystallinity (4.3 to 10.1%) of the chitosan films. Mitochondrial activity and membrane integrity of OECs was significantly different for OECs cultivated on chitosan with DDAs below 75%, while those on films with DDAs up to 85% were similar to cells in asynchronous growth. Apoptotic indices and cell cycle analysis also suggested that chitosan films with DDAs below 75% were cytocompatible but induced cellular stress, while OECs grown on films fabricated from chitosan with DDAs above 75% showed no significant differences compared to those in asynchronous growth. Tensile strength and elongation to break varied with DDA from 32.3 to 45.3 MPa and 3.6 to 7.1% respectively. DDA had no significant influence on abiotic and biotic degradation profiles of the chitosan films which showed approximately 8 and 20% weight loss respectively. Finally, perceived patterns in property changes are subject to change based on potential variations in DDA analysis. NMR examination of the chitosan samples here revealed significant differences depending upon which peaks were selected for integration; 6 to 13% in DDA values within individual samples. Furthermore, differences between DDA values determined here and those reported by the commercial suppliers were significant and this may also be a source of concern when selecting commercial chitosans for biomaterial research.

No MeSH data available.


Related in: MedlinePlus