A Poly-N-isopropylacrylamide Based Hydrogel as a Novel Material for Vitreous Replacement

Abstract

<p>Although improvements in vitreous replacement technologies have lead to more desirable outcomes in patients with vision problems such as retinal detachment and vitreous hemorrhage, there remain a number of issues with current approaches. Many common therapies are limited to specific cases, or require extensive post-operative positioning, follow-up, and even secondary surgery for removal.</p> <p>Thermally responsive materials composed of N-isopropylacrylamide, N-acryloxysuccinimide, and poly(ethylene glycol) were obtained through free-radical polymerization and were examined for the potential for use as artificial vitreous replacements. While in solution these materials were capable of transitioning from free-flowing liquids at room temperature to viscous solutions at physiological temperatures. Solutions of these materials were shown to have refractive indices similar to currently used vitreous replacements and gel-like mechanical properties at 37^oC. Optical transparency studies were performed and most samples displayed adequate transmittance values in the visible spectrum. Co-monomer content and molecular weight were found to have an effect on the temperature of the phase transition, as well as the transparency and cellular compatibility of the solutions at 37^oC.</p> <p>While the materials studied require further optimization, these results suggest that poly(N-isopropylacrylamide) based polymers may have potential for use in vitreous replacement therapies</p>