Dressing development

Why doesn't Mānuka honey soak into normal dressing material? How did scientists at the University of Waikato overcome this problem?

Transcript

Peter Molan (University of Waikato)

The first challenge was getting the honey into the pads [wound dressings] because all the water in honey is tied up with the sugar. It doesn’t actually bind to the cellulose fibres, the cotton fibres, and doesn’t wet the dressing.

I found that by heating the honey - to break the hydrogen bonds and release the water from the sugar molecules - it did allow it to wet the cotton fibres, and we could get it to soak into the dressings. We didn’t use those though on patients because the fibres from that can end up getting embedded in the tissue as foreign objects when the wound heals. We went on to use ones which were enclosed in a fabric outer to stop fibres from shedding [into the wound].

Julie Betts (Health Waikato)

The good things were that you had an amount of honey that would last a wee while. The bad things were it stuck to the wound, which was not a pleasant task to remove it for the patient or the person removing it. If you had a wound that oozed quite a lot then you didn’t get the honey working over a 24 hour period so you were on a bit of rollercoaster in terms of the healing and control of bacteria.

We had to figure out a way that we could get a standard amount of honey on a wound and have it stay there.

Peter Molan (University of Waikato)

I then tried using alginate fibres. Somebody supplied soft alginate fibre, the ‘m’-type, and that one did readily soak up the honey. The advantage of using the alginate fibre is that if bits do break off in the wound they dissolve and they’re biodegradable.

So there’s no problem with residues from those being left in the wound. But the other advantage of them, we found, was that as the calcium alginate in the fibre picks up sodium from the wound fluid, it then turns into sodium alginate that’s soluble and it forms a gel. The honey couldn’t be washed through the dressing because the dressing became a gel.