Rosmarinic acid-grafted gelatin nanogels for efficient diquafosol delivery in dry eye disease therapy

Dry eye disease (DED) is a prevalent ocular disorder characterized by unstable tear film condition with loss of aqueous or mucin, excessive oxidative stress, and inflammation, leading to discomfort and potential damage to the ocular surface. Current DED therapies have shown restricted therapeutic effects such as frequent dosing and temporary relief with potential unwanted side effects, urgently necessitating the development of innovative efficient therapeutic approaches. Herein, we developed rosmarinic acid (RosA) conjugated gelatin nanogels loading diquafosol sodium (DQS), DRGNG, for simultaneous ROS-scavenging and mucin-secreting DED treatment. Mechanically, DRGNG suppressed the production of ROS, reduced inflammatory factors, and prompted mucin secretion in vitro and in vivo. The whole transcriptome RNA sequencing in vitro further provided a detailed analysis of the upregulation of anti-oxidant, anti-inflammatory, and mucin-promotion pathways. Therapeutically, both in evaporative DED and aqueous deficient DED models, the dual-functional DRGNG could prolong the retention time at the ocular surface, efficiently suppress the oxidative stress response, reverse ocular surface morphology, and recover tear film homeostasis, thus alleviating the DED when the dosage is halved compared to the commercial Diquas®. Our findings contribute to developing innovative therapies for DED and offer insights into the broader applications of nanogels in ocular drug delivery and oxidative stress-related conditions.