Synthesis and application of cucumber extract-loaded hydrogels based on oxidized carboxymethyl cellulose and alginate as vitreous replacements.

Retinal detachment is a leading cause of blindness worldwide, with current treatments using silicone oil or expanded gases to facilitate reattachment. Polymeric hydrogels are a promising alternative due to their optical clarity, rheological properties, and biodegradability. In this study, we synthesized polymeric hydrogels by crosslinking oxidized carboxymethyl cellulose and sodium alginate with calcium chloride and introduced cucumber extract, a plant-based antioxidant rich in flavonoids and phenolics, known for its anti-inflammatory properties. The resultant hydrogels demonstrated a swelling ratio of about 350 %, showed moderate hydrophilicity with a contact angle of 48° in Stimulated Tear Fluid and achieved ~90 % transparency in the visible range. Mass retention studies showed over 80 % retention in phosphate-buffered saline and 30 % in Stimulated Tear Fluid at 672 h, indicating long term structural stability. In-vitro drug-release experiments revealed a sustained release of flavonoids and phenolic compounds for up to 672 h, providing extended therapeutic potential with minimal burst release. Cytocompatibility evaluation using NIH/Swiss embryo fibroblasts showed excellent cell viability, confirming the biocompatibility of the system. These findings suggest that the synthesized hydrogels offer a viable alternative to current vitreous substitutes, potentially improving patient outcomes and reducing complications.