Ginger-Derived Nanoparticles Deliver a VEGFA-Targeting DNAzyme and Modulate Retinal VEGFA Expression and Inflammatory Markers in Experimental Diabetic Retinopathy.

Abstract

Purpose: To address the limitations of current anti-vascular endothelial growth factor (anti-VEGF) therapies for diabetic retinopathy (DR), which do not effectively inhibit VEGFA synthesis at the genetic source and provide only marginal improvements in the chronic inflammatory microenvironment, this study employs ginger-derived nanoparticles (GDNPs) to create a deoxyribozyme (DNAzyme) delivery system (GDNPs@Dz) targeting VEGFA mRNA. It further investigates the combined effects of this system on gene silencing and anti-inflammatory activity in an experimental setting.

Methods: GDNPs were isolated from fresh ginger using differential centrifugation followed by size-exclusion chromatography purification, and their physicochemical properties and biosafety were characterized. Phosphorothioate-modified 10-23 DNAzyme was incorporated into GDNPs via ultrasonication. The uptake of GDNPs@Dz by human retinal microvascular endothelial cells was evaluated in vitro, alongside its inhibitory effects on cell migration and tube formation. In a streptozotocin-induced DR mouse model, the study assessed the intraocular retention of the AF647-labeled DNAzyme signal, VEGFA expression, and inflammatory markers (IL-1β, TNF-α) following a single intravitreal injection (2 μL/eye, 39 pmol DNAzyme + 4 μg GDNPs). Treatment doses in vitro were 500 nM free DNAzyme, 50 μg/mL empty GDNPs, or an equivalent combination. All in vitro experiments were performed in three independent biological replicates, with three technical replicates per condition, and in vivo analyses used n = 3 animals per group per time point, with VEGFA expression assessed at days 3, 7, 10, 14, and 21.

Results: GDNPs@Dz was internalized by retinal microvascular endothelial cells and reduced high glucose-induced cell migration and tube formation in vitro. In the diabetic mouse model, GDNPs@Dz prolonged the ocular retention of the AF647-labeled DNAzyme signal compared with free DNAzyme and reduced retinal VEGFA mRNA for up to two weeks after a single injection. Representative immunofluorescence showed reduced IL-1β and TNF-α positive signals after empty GDNPs treatment. These findings indicate a combined effect of gene silencing and anti-inflammatory activity.

Conclusion: This preclinical proof-of-concept study demonstrates that ginger-derived nanoparticles can deliver a VEGFA-targeting DNAzyme and modulate retinal VEGFA expression and inflammatory markers in an experimental diabetic setting. The system showed a favorable biosafety profile and combined gene-silencing and anti-inflammatory activity, providing a basis for further preclinical development.