Abstract: An insertion device for an intra-ocular lens (IOL) has a bilaminar, lubricious coating on the surface which contacts the IOL as it is being inserted into the eye. The bilaminar coating includes a highly lubricious top coat, and a polymeric base coat which is both highly adherent to the surface of the insertion device, and which has functional groups capable of grafting the base coat to the top coat. In its completed form, the bilaminar coating is essentially permanent, and exceedingly lubricious when wet, allowing the IOL to be advanced smoothly and without damage through the insertion device. The top coat may include hyaluronan, or another material capable of providing the required lubricity.

Abstract: A free acid form of a polysaccharide is produced from its alkali-metal salt. In one example, free-form hyaluronic acid is produced by preparing a solution of an alkali-metal salt of hyaluronic acid, dispersing into the solution a strong acid, enclosing the dispersion within a semi-permeable membrane, dialyzing the dispersion in water, and harvesting the product from within the membrane. The strong acid can be hydrochloric acid, sulfuric acid, nitric acid, orthophosphoric acid, or oxalic acid, for example. The semi-permeable membrane is non-ionic, and has a molecular weight cut-off large enough to pass the strong acid, and preferably much larger. The invention provides a simple and economical way to produce a product which is not commercially available.