Intravitreal CBD-loaded niosomes enhance retinal neuroprotection in ischemic injury

Cannabidiol (CBD) has emerged as a promising treatment for conditions like retinal ischemia, characterized by reduced blood flow to the retina and significant vision loss. Despite its therapeutic potential, CBD's clinical application could be limited by due to its low bioavailability. This study investigates the efficacy of CBD-loaded niosomes as a neuroprotective formulation for the use in ocular therapies related to retinal ischemia. We investigated the neuroprotective effects of CBD using a nanodispersed system (niosomes) administered via intravitreal injection in rats' eyes. Niosomes underwent characterization for size, distribution, zeta potential, morphology, and encapsulation efficiency. Safety and neuroprotective activity were assessed by electroretinography (ERG), confocal and transmission microscopy and histology. Niosomes exhibited nanometric size (100-400 nm) and stability, showing good tolerance in animals. ERG results demonstrated higher b-wave amplitudes in animals pre-treated with niosomes + CBD compared to the control group following ischemic injury induced by a sudden increase in IOP. Histological and confocal microscopy analyses of retinas from the niosomes + CBD group showed preserved structure compared to the ischemic control group, suggesting significant retinal protection by intravitreally injected niosomes + CBD before ischemia. CBD-loaded niosomes effectively preserved retinal function, highlighting the neuroprotective potential of CBD against retinal ischemia. This formulation presents a promising and innovative treatment for ischemic retinal diseases.