Jamie Mistry

NOVEL CHITOSAN-ALGINATE FIBRES FOR ADVANCED WOUND DRESSINGS

ABSTRACT A range of commercial chitosans were sourced and their molecular size profiles and degrees of acetylation (DA) were determined by HPSEC and 1 H-NMR spectroscopy, respectively. Chitosans were subsequently utilised for modification of alginate fibres, and levels of chitosan incorporated into base fibres were estimated by elemental analysis. Elongation (%) and tenacity of resultant chitosan/alginate fibres were determined in order to assess their potential application in wound dressings. A range of chitosan contents (˜ 0-6 % w/w) resulted from a variety of alginate and chitosan starting materials. Fibres produced from sodium alginate (A1, 6%) using hydrochloric acid (0.2M) at a draw ratio of 1.18, and treated with chitosan (C1, 3.2%) were deemed to have the best properties. In general, use of a water washing stage resulted in the production of better chitosan/alginate fibres. Treatment with chitosans generally resulted in a reduction in tenacity (and a reduction in % elongation if a water washing stage was not used), i.e. no increase in fibre strength was observed, implying that the chitosan is more like a coating rather than penetrating/reinforcing the alginate fibre.

MODIFICATION OF ALGINIC ACID FIBRES WITH HYDROLYSED CHITOSANS

ABSTRACT A range of commercial chitosans were subjected to controlled acid hydrolysis and their molecular size profiles and degrees of acetylation (DA) were determined (post-hydrolysis) by HPSEC and 1 H-NMR spectroscopy, respectively. Hydrolysed chitosans were subsequently utilised for modification of alginic acid/sodium alginate fibres, and levels of hydrolysed chitosan incorporated into base fibres were estimated by elemental analysis. Tensile properties (elongation % and tenacity) of resultant chitosan/alginate fibres were also determined. A broad range of hydrolysed chitosan contents (˜ 7-25 % w/w) were obtained (significantly higher than using unhydrolysed chitosans). Fibres produced from either alginate A1 (6%), using HCl (0.2M), a draw ratio of 1.18, treated with hydrolysed chitosan C3 (3.9%), or from alginate A3 (4%), using HCl (0.5M), a draw ratio of 1.18, treated with hydrolysed chitosan C3 (3%), had the best properties.