Refilling of ocular lens capsule with copolymeric hydrogel containing reversible disulfide

Polymer solutions can fill any potential irregular cavity using minimally invasive techniques and thus have potential uses in ophthalmology. We prepared acrylamide hydrogels containing disulfide bonds by free radical polymerization in aqueous ethanol. The hydrogels were liquefied using dithiothreitol to yield water-soluble acrylamide copolymers containing pendant thiol (-SH) groups. The weight average molecular weights of the copolymers ranged from 1.43 × 10⁵ to 9.22 × 10⁵ daltons by GPC. Ellman's analysis and Raman spectroscopy confirmed the presence of -SH. The aqueous solutions of these purified thiol-containing copolymers were oxidized with 3,3′-dithiodipropionic acid or air to reform the hydrogels. The moduli of the reformed hydrogels ranged from 0.27 to 1.1 kPa depending on concentration and thiol content. Rapid endocapsular gelation yielded optically clear gel within the lens capsular bag. This technique now enables us to validate methods to determine the biomechanics of the lens and its role in accommodation.