Ophthalmic biomaterials and preparation thereof

Composite interpenetrating network (IPN) of PDMS and PNIPAAM was formed to generate polymers with oxygen and glucose permeability as well as improved wettability compared to PDMS homopolymers and greater mechanical strength than PNIPAAM homopolymers. Transparent vinyl and hydroxyl terminated PDMS/PNIPAAM IPNs (PDMS-V and PDMS-OH IPNs respectively) were successfully synthesized. Transmission electron microscopy images verified the structure of the IPNs. Surface analysis suggested that PNIPAAM was present on the surface as well as in the bulk material. PDMS-OH IPNs generated from a PDMS-OH matrix cured in the presence of solvent had the highest glucose permeability at 10cm /s, comparable to that of the native cornea. The LCST phenomenon remained in these materials, although changes were not as abrupt as with pure PNIPAAM. These results suggest that these materials may be further developed as ophthalmic biomaterials or for controlled drug release applications.