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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

Images showing change in surface hydrophobicity for solvent cast films fabricated from commercial chitosan samples with (a) 72 and (b) 85% DDA.
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pone.0135153.g012: Images showing change in surface hydrophobicity for solvent cast films fabricated from commercial chitosan samples with (a) 72 and (b) 85% DDA.

Mentions: Surface chemistry and morphology are known to influence cellular response [42,43]. In the study here, Fig 12 clearly shows that the chitosan film with a DDA of 73% had a significantly lower water contact angle than its counterpart with a DDA of 85%. Films with DDAs of 72 to 75% had similar contact angle of about 65 ± 3°, increasing DDA further resulted in a gradual increase in contact angle to 103 ± 2° (Fig 13). These results suggest a gradual increase in hydrophobicity as DDA increases. However, Tomihata et al. report that increasing chitosan DDA decreases hydrophobicity, while Wenling et al. claims that there is no pattern to the relationship between DDA and hydrophobicity [44,11]. These contradicting reports can be readily explained by differences in chitosan film preparation and their effects on the surface charge. Changes in availability of the amine groups may not only have affected water contact angles, but adhesion of biological macromolecules when incubated in culture media, thus supporting the OEC proliferation trend observed in Fig 8.


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)

Images showing change in surface hydrophobicity for solvent cast films fabricated from commercial chitosan samples with (a) 72 and (b) 85% DDA.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0135153.g012: Images showing change in surface hydrophobicity for solvent cast films fabricated from commercial chitosan samples with (a) 72 and (b) 85% DDA.
Mentions: Surface chemistry and morphology are known to influence cellular response [42,43]. In the study here, Fig 12 clearly shows that the chitosan film with a DDA of 73% had a significantly lower water contact angle than its counterpart with a DDA of 85%. Films with DDAs of 72 to 75% had similar contact angle of about 65 ± 3°, increasing DDA further resulted in a gradual increase in contact angle to 103 ± 2° (Fig 13). These results suggest a gradual increase in hydrophobicity as DDA increases. However, Tomihata et al. report that increasing chitosan DDA decreases hydrophobicity, while Wenling et al. claims that there is no pattern to the relationship between DDA and hydrophobicity [44,11]. These contradicting reports can be readily explained by differences in chitosan film preparation and their effects on the surface charge. Changes in availability of the amine groups may not only have affected water contact angles, but adhesion of biological macromolecules when incubated in culture media, thus supporting the OEC proliferation trend observed in Fig 8.

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