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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 health of olfactory ensheathing cells when cultivated (DMEM media, 5 days, 37°C, 5% CO2) on solvent cast films fabricated from commercial chitosan samples with different DDAs, as measured by: (a) mitochondrial activity, expressed as % of cells in asynchronous growth (100%), and membrane integrity expressed as % of lysed cells (100%); (* Significant difference, P < 0.05, n ≥ 3).
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pone.0135153.g009: Variation in health of olfactory ensheathing cells when cultivated (DMEM media, 5 days, 37°C, 5% CO2) on solvent cast films fabricated from commercial chitosan samples with different DDAs, as measured by: (a) mitochondrial activity, expressed as % of cells in asynchronous growth (100%), and membrane integrity expressed as % of lysed cells (100%); (* Significant difference, P < 0.05, n ≥ 3).

Mentions: Consistent with the proliferation data and cell observations, OECs cultivated on chitosan films with DDAs of 72 and 73% showed significantly less mitochondrial activity, as measured by MTS, around 84 ± 4% of that of cells exhibiting asynchronous growth in the absence of biomaterials (assigned 100%, Fig 9A). While cells cultivated on films fabricated from chitosan with 75 to 79% DDA showed no significant difference from the asynchronous OECs, those cultivated on films with 85% DDA possessed 87 ± 2% of the mitochondrial activity exhibited by the asynchronous cells (Fig 9A). The data suggests that OECs proliferating on the films of chitosan films with comparatively high DDA (85%) had reached over confluence. Similarly, there were no significant differences in membrane permeability, (Fig 9B). Cells grown in the presence of nocodazole as a positive control had a significant percentage of their population, 62 ± 3%, necrotic and 31 ±7% apoptotic. In contrast, the control of cells exhibiting asynchronous growth possessed 21 and 7% of the cell populations necrotic and apoptotic respectively, validating the experiment (Fig 10). Consistent with the cell proliferation data, OECs cultivated on chitosan films with increasing DDA showed less necrotic cells. On films with a chitosan DDA of 72%, 30 ± 3% of the population were necrotic, compared to 20 ± 3% of their counterparts on chitosan with 85% DDA. However, populations grown on chitosan films with 79 and 85% DDA appeared to possess greater proportions of cells exhibiting early apoptosis, 18 ± 4% compared to 10 ± 3% for those grown on chitosan with 72% DDA (Fig 10). Thus, OECs cultivated on films fabricated from chitosan with 79 and 85% DDA exhibited similar necrotic cell percentages as cells exhibiting asynchronous growth but greater proportions of the population exhibiting apoptosis, approximately 21% (Fig 10).


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 health of olfactory ensheathing cells when cultivated (DMEM media, 5 days, 37°C, 5% CO2) on solvent cast films fabricated from commercial chitosan samples with different DDAs, as measured by: (a) mitochondrial activity, expressed as % of cells in asynchronous growth (100%), and membrane integrity expressed as % of lysed cells (100%); (* Significant difference, P < 0.05, n ≥ 3).
© Copyright Policy
Related In: Results  -  Collection

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

pone.0135153.g009: Variation in health of olfactory ensheathing cells when cultivated (DMEM media, 5 days, 37°C, 5% CO2) on solvent cast films fabricated from commercial chitosan samples with different DDAs, as measured by: (a) mitochondrial activity, expressed as % of cells in asynchronous growth (100%), and membrane integrity expressed as % of lysed cells (100%); (* Significant difference, P < 0.05, n ≥ 3).
Mentions: Consistent with the proliferation data and cell observations, OECs cultivated on chitosan films with DDAs of 72 and 73% showed significantly less mitochondrial activity, as measured by MTS, around 84 ± 4% of that of cells exhibiting asynchronous growth in the absence of biomaterials (assigned 100%, Fig 9A). While cells cultivated on films fabricated from chitosan with 75 to 79% DDA showed no significant difference from the asynchronous OECs, those cultivated on films with 85% DDA possessed 87 ± 2% of the mitochondrial activity exhibited by the asynchronous cells (Fig 9A). The data suggests that OECs proliferating on the films of chitosan films with comparatively high DDA (85%) had reached over confluence. Similarly, there were no significant differences in membrane permeability, (Fig 9B). Cells grown in the presence of nocodazole as a positive control had a significant percentage of their population, 62 ± 3%, necrotic and 31 ±7% apoptotic. In contrast, the control of cells exhibiting asynchronous growth possessed 21 and 7% of the cell populations necrotic and apoptotic respectively, validating the experiment (Fig 10). Consistent with the cell proliferation data, OECs cultivated on chitosan films with increasing DDA showed less necrotic cells. On films with a chitosan DDA of 72%, 30 ± 3% of the population were necrotic, compared to 20 ± 3% of their counterparts on chitosan with 85% DDA. However, populations grown on chitosan films with 79 and 85% DDA appeared to possess greater proportions of cells exhibiting early apoptosis, 18 ± 4% compared to 10 ± 3% for those grown on chitosan with 72% DDA (Fig 10). Thus, OECs cultivated on films fabricated from chitosan with 79 and 85% DDA exhibited similar necrotic cell percentages as cells exhibiting asynchronous growth but greater proportions of the population exhibiting apoptosis, approximately 21% (Fig 10).

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