Abstract: The invention relates to macromolecular hydrophilic photocrosslinkers having polymeric backbones of substituted ethylene groups carrying photoactive groups. The photocrosslinkers are capable of producing, when being exposed to light of determined wavelengths above 305 nm, radicals which are retained on the macromolecular photocrosslinkers and reacting so as to accomplish a crosslinked network structure. The invention further relates to the preparation of photocrosslinkers, their use in different aqueous systems and their utility in production of medical devices including ophthalmic lenses.

Abstract: The present invention relates to new hydrogels with improved mechanical properties and methods of their preparation. The hydrogels are formed from hydrophilic polymers having function hydroxyl groups and have low elasticity modulus typically less than about 10 kPa, a tensile strength above 1 Mpa, an elongation above 50% which makes suitable as medical implants, in particular intraocular lenses. The hydrogels are prepared by a crosslinking method with a comparatively low concentration of hydrophilic polymer of a sufficiently high molecular weight dissolved in a good solvent.