Novel materials for moist wound management: Alginate-psyllium hybrid fibres

Objective: To assess the feasibility of producing high absorbing, high gelling hybrid fibres made from alginate and psyllium. Method: Three methods of psyllium extraction were attempted: the hot, cold and hydrolysed method. The extracted psyllium was sieved before addition to the alginate dope. To assess feasibility, each dope was in turn extruded on a bench-top extruder and then on a pilot-size wet extruder. Calcium chloride solution was used as the coagulation medium for all the extrusions. The produced fibres were subsequently assessed for their linear density, tensile strength, absorption characteristics and swelling behaviour. Optical microscopy was also used to illustrate hybrid fibre swelling behaviour under different conditions Results: This feasibility study has shown that hybrid fibres can be produced when using different methods of psyllium extraction, proving the feasibility of the proposed methodology. However, based on physical and functional assessment of the fibres, it was found that the cold water extraction method leads to better hybrid fibres with superior tensile properties, liquid absorption and swelling, which would render them most suitable for heavily exudating wounds. Conclusion: The cold water route is found to be the most effective way of producing polysaccharide-based hybrid fibres. This method is also the least expensive, both in terms of room temperature preparations and functional effectiveness, using only 0.75% psyllium. This fibre is therefore recommended for wound dressing applications.