Peptide dendrimer and hyaluronic acid modified nanovesicles for ocular delivery of timolol maleate and siRNA

Glaucoma, a leading cause of irreversible blindness, is characterized by retinal ganglion cell (RGC) degeneration due to elevated intraocular pressure (IOP) and apoptosis. While timolol maleate effectively lowers IOP, it does not prevent RGC loss and suffers from poor corneal permeability and rapid clearance. This study introduces a novel dual-delivery nanovesicular system employing multifunctional spanlastics to simultaneously lower IOP and inhibit RGC apoptosis via caspase-2 gene silencing. The system comprises two distinct nanovesicle populations: (i) timolol-loaded vesicles conjugated with peptide dendrimers to enhance corneal penetration and anterior segment delivery; and (ii) siRNA-loaded vesicles targeting Caspase-2, coated with hyaluronic acid for posterior segment delivery and gene silencing. This is the first approach integrating IOP reduction with targeted genetic intervention to protect RGCs. Formulations were optimized using a Design of Experiments approach and showed desirable physicochemical properties, sustained release, improved transcorneal permeability, and 1-month stability at 4 °C. In vitro studies confirmed Caspase-2 silencing and apoptosis reduction in RGC-5 cells, while in vivo results demonstrated prolonged IOP control. Safety was confirmed via histopathological and ocular irritation assessments. This targeted, non-invasive dual-delivery platform offers a promising therapeutic strategy for comprehensive glaucoma management.