Advanced wound care materials: developing an alginate fibre containing branan ferulate

This laboratory-based study set out to establish whether branan ferulate--a polysaccharide compound available in gels such as as Sterigel (SSL International, UK)--could be successfully added to the fibre of an alginate dressing to provide a superior wound-care dressing.

A wet extruder (Howden Engineering Services, UK) was used to produce the fibres. Researchers examined the effect of spinning-bath calcium chloride concentration (used as the coagulant in the fibre-spinning process) on the tensile and absorption properties of alginate fibres containing 25% w/w branan ferulate. Sodium alginate and branan ferulate were separately dissolved in de-ionised water and then stirred together to make up a 5% dope solution. The dope was then forced through a spinneret and into the calcium chloride bath, where fibres were precipitated and then carried over the first set of rollers. The fibres were washed in the next bath and drawn at different rates to enhance their tensile properties. At the 'winding-up' stage the filaments were either passed over a contact heater and into a furnace (dry pick-up) or transferred into acetone baths of increasing concentrations of 50, 80 and 100% aqueous acetate to remove the water (wet pick-up). The moisture content of standard alginate fibres and those with branan ferulate were measured and compared. Breaking load, tenacity and breaking extension, and the quantity of branan ferulate in the fibres were also measured. The process was repeated four times, using different strengths of calcium chloride. Using various draw ratios, the effects of liquid uptake were measured using water, saline and a solution called A (to mimic human blood and exudate-type fluids).

Out of the four calcium chloride concentrations used, 1% concentration appeared to give the highest and most conclusive results for fibre-breaking load, tenacity and breaking extension.

A 1% w/v concentration of calcium chloride provides the optimum conditions for achieving suitably strong fibres with adequate absorption capacity, while allowing the least branan ferulate loss during wash and post-production treatments. In a laboratory setting the product showed promise. Research is now needed in a clinical setting and for comparison with existing wound-care products.