A Light‐Activatable Nitric Oxide Donor for Targeted Glaucoma Therapy with Real‐Time Monitoring Capabilities

Abstract Primary open‐angle glaucoma (POAG), the most common form of glaucoma, is characterized by a gradual increase in intraocular pressure (IOP). Nitric oxide (NO) donors are promising treatments for POAG, but their effectiveness requires selective NO release triggered by ocular‐relevant stimuli. RhNO‐Ab, a visible light‐activatable NO donor and fluorescent probe is introduced. RhNO‐Ab releases NO from its N‐nitroso group and transforms from a non‐fluorescent spirolactone to fluorescent Rhodamine (Rh) upon NO release. In vitro studies, including in bulk and single molecule level demonstrated a rapid NO release and fluorescence recovery upon light irradiation. Immunofluorescence shows enhanced delivery to target tissues of RhNO‐Ab with ABCA1 antibody modification. Administration of RhNO‐Ab with light at 30, 20, and 10 µ m significantly reduces IOP in NOS3 KO mice by 2.11 mmHg (12.50%, n = 6), 1.77 mmHg (9.88%, n = 6), and 1.55 mmHg (8.23%, n = 6) 3 h post‐treatment ( * p < 0.05). RhNO‐Ab with light also reduces transendothelial electrical resistance (TEER) in Schlemm's canal (SC) endothelial cells (n = 3, * p < 0.05) and upregulates soluble guanylate cyclase (sGC) mRNA and protein expression in mouse outflow tissues and human trabecular meshwork (HTM) cells. Unlike traditional NO donors, RhNO‐Ab offers visible light‐triggered therapeutic NO release and real‐time monitoring, making it a promising novel strategy for POAG treatment.