Abstract
Purpose :
Angiogenesis is a major cause of vision loss and blindness in numerous ocular diseases, including in the cornea, macular degeneration, and diabetes. To treat angiogenesis, laser photocoagulation, photodynamic therapy, and anti-vascular endothelial growth factor therapy such as bevacizumab (BEV) are often utilized, but these treatments can damage adjacent healthy tissue or require frequent administration and can carry a risk of infection. To improve the treatment efficiency, increase the treatment duration, and reduce these side-effects, the current study describes a novel treatment of ocular angiogenesis using miniature biodegradable silicon nanoneedles (SiNNs) fabricated on a tear-soluble contact lens.
Methods :
The SiNNs were encapsulated with BEV (BEV@SiNNs) and used as drug carriers for long-term, sustained drug delivery. The potential treatment effects of BEV@SiNNs were evaluated on a rabbit corneal neovascularization (CNV) model (n = 24) after approval from the University of Michigan IACUC. To generate CNV, a suture was placed on the animal cornea and allowed for CNV development up to one month. BEV@SiNNs were applied on the cornea and monitored by optical coherence tomography (OCT), color photography, and red-free imaging. The treatment outcome was followed up for one-month post-treatment.
Results :
The tear-soluble contact lens dissolved within 1 minute. CNV was rapidly reduced within 7 days post-treatment that persisted to at least 28 days (Figure) whereas no CNV reduction occurred with control. Vessel density was 2.9 ± 2.0% for BEV@SiNNs versus 85.8 ± 0.9% for control. SiNNs did not cause cytotoxicity. Histological images showed normal corneal morphology without evidence of cell death or damage to the corneal endothelium cells, corneal thickness, and limbal stem cells.
Conclusions :
The SiNNs are an efficient drug delivery vehicle for treatment of ocular angiogenesis.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.