Protein interaction with hydrogel contact lenses

The first event observed at the interface between a contact lens and tear fluid is protein adsorption. Tears have a rich and complex composition, allowing a wide range of interactions and competitive processes. The majority of studies avail-able on protein adsorption have focused on blood/plasma/serum protein on solid surfaces. However, recently the interaction of tear proteins with contact lenses has become an important field of research following the widespread use of contact lenses in many physiological and pathological conditions. Protein adsorption on contact lenses is the overall result of various types of in-teractions between the different components present, i.e. the chemical composition and the surface charge, the structure of the protein molecules, the nature of the medium (tears) and many other solutes present in tears. The chemical structure of contact lenses and their physical and biological behavior are considered, followed by tear film structure and biochemistry. Finally, the nature and mechanism of protein adsorption on contact lenses, factors affecting adsorption and attempts to reduce protein ad-sorption are reviewed. (Journal of Applied Biomaterials & Biomechanics 2004; 2: 1-19).