Arrested Phase Separation Enables High-Performance Keratoprosthesis.

Corneal transplantation is impeded by donor shortages, immune rejection, and ethical reservations. Pre-made cornea prosthesis (keratoprosthesis) offers a proven option to alleviate these issues. Ideal keratoprosthesis must possess optical clarity and mechanical robustness, but also high permeability, processability and recyclability. Here we show that rationally controlling the extent of arrested phase separation can lead to optimized multiscale structure that reconcile permeability and transparency, a previously conflicting goal by common pore-forming strategies. The process is simply accomplished by hydrothermally treating a dense and transparent hydrophobic association hydrogel. The examination of multi-scale structure evolution during hydrothermal treatment reveals that the phase separation with upper miscibility gap evolves to confer time-dependent pore growth due to slow dynamics of polymer-rich phase which is close to vitrification. Such a process can render a combination of multiple desired properties that equal or surpass those of the state-of-the-art keratoprosthesis. In vivo tests confirm that our keratoprosthesis can effectively repair corneal perforation and restore a transparent cornea with treatment outcomes akin to that of allo-keratoplasty. Our keratoprosthesis is easy to access and convenient to carry, thus it would be an effective temporary substitute for a corneal allograft in emergency condition. This article is protected by copyright. All rights reserved.