Influence of the degree of acetylation on some biological properties of chitosan films.

In this study, we investigated in vitro the role of the degree of acetylation (DA) on some biological properties of chitosan films. We noticed that, whatever the DA, all chitosan films were cytocompatible towards keratinocytes and fibroblasts. We also demonstrated that the higher the DA of chitosan, the lower was the cell adhesion on the films. Fibroblasts appear to adhere twice as much as keratinocytes on these materials. We observed that keratinocyte proliferation increases when the DA of chitosan films decreases. Thus, DA influences the cell growth in the same way as cell adhesion. On the other hand, although they remain alive, fibroblasts do not proliferate on chitosan films. This behaviour is related to an extremely high adhesion on this kind of material, which certainly inhibits cell growth. In conclusion, DA plays a key role in cell adhesion and proliferation, but does not change the cytocompatibility of chitosan. In parallel, it is also important to notice the role played by the surface morphology of the material, a second major parameter which influences the mechanism of adhesion.