Fast in situ enzymatic gelation of PPO-PEO block copolymer for injectable intraocular lens in vivo.

Foldable intraocular lenses (IOLs) have been utilized to substitute natural lens of cataract patients. In this study, we developed a fast, in situ gelable hydrogel requiring no toxic agent as an injectable IOL material. A 4-armed PPO/PEO-phenol conjugate by a non-degradable linker was synthesized to form a hydrogel in situ by horseradish peroxidase. The gelation time and modulus could be controlled, ranging from 20 s to 2 min and from 1 to 43 kPa. The adhesion of human lens epithelial cells on the hydrogel was significantly reduced compared to that on commercial IOLs. The hydrogels were injected into the rabbit eyes to evaluate the in vivo biocompatibility for 8 weeks. Corneal endothelial cell loss and central corneal thickness were comparable with the common IOL implantation procedure. Histologically, the cornea and retina showed the intact structure. The change of refraction after application of pilocarpine was +0.42 D preoperatively and +0.83 D postoperatively, which may indicate the maintenance of accommodation amplitude.