If Polymer strands lie together like spaghetti, the polymer is insoluble. If each strand is totally surrounded by solvent which requires groups on the sides of the strands to provide solubilising interactions, the polymer dissolves. If the polymer is basically soluble but the strands are linked in places, the material may form a gel.
Synthetic gels gain solubility through carboxylic acids and are tied by cross links. Because synthetic cross linking is random, no special additional attributes arise. Solubilising groups such a carboxylic acids tend to feel tacky and if neutralized e.g by sweat/perspiration acids the gel will break down.
Nemidon is based on seaweed derived sugar polymers and is solubilised by hydroxyl groups which are sufficiently non interactive and water like. No tackiness follows and the gel is stable to all chemicals found on skin or used in cosmetic/pharmaceutical preparations. Nemidon is totally soluble in hot water but gels on cooling through hydrogen bonds. (These hold the strands DNA together) Seaweeds have designed the spacing of these cross links in order to encapsulate chemicals of value to them, hence we can also used these spaces. Because the hydrogen bonds are weak but instantly reformed by rubbing allowing the release of encapsulated material. Alternatively water and solution can pass rapidly through the large pores permitting rapid availability and because the free energy requirement to pass moisture in or out of the gel is close to zero, it is an excellent moisturizer/regulator.