Choosing the Right Seaweed Polymer for Making Surface Coatings

What is it about?

Polyelectrolyte multilayers (PEMs) are surface coatings made from stacking a postitively charged polymer on top of a negatively charged one, and repeating this process until a thicker layer is created. They are easy to make, and are used often in research into drug delivery (getting medicine to the right part of the body) and anti-fouling (to stop material from being coated by microbes). Natural sugar-based polymers (polysaccharides) are favoured in many biologically-relevant studies (biomaterials), as they are harmless and compatible with living systems. A lot of research is dedicated to finding and exploiting the chemistry of different polysaccharides in these surface coatings. One very common polysaccharide in these dual component films is chitosan, a polymer derived from crustacean shells. In this paper, we coupled chitosan with a more novel natural polymer - fucoidan - a sulfated polysaccharide derived from seaweed. The core of the work was a comparison of coatings made using fucoidan extracted from two different types of seaweed. The selection of one or other of the fucoidans resulted in coatings with altered thicknesses, surface roughness, and hydration.

Featured Image

Why is it important?

The physical and chemical characteristics of multilayers are important for their use as surface coatings. If they are hydrophobic, they can be used for oil/water separation. Their morphology (rough or smooth) controls how well cells can attach to them, which has implications for their use in tissue growth applications. If they are thick and well-hydrated then they might find use as an aqueous lubricant. Being able to tune these characteristics without having to alter the chemistry dramatically means that the multilayer coatings may find a wider array of potential uses.

Perspectives