Collagen-Based Gel as a Potential Transscleral Drug Delivery System for Age-Related Macular Degeneration

Abstract

Purpose: : Age related macular degeneration (AMD) is a chronic inflammatory eye disease that gradually destroys sharp, central vision. With the introduction of novel anti-angiogenic agents, clinical treatment is currently possible only for the wet form of the disease and with frequent intravitreal injections. However, frequent intravitreal injection therapy carries a risk of complication and generates understandable issues of patient acceptability. There is a clear need for a delivery system that either bypasses the need for ocular injection or reduces its frequency to treat wet as well as dry AMD.

Methods: : Transcleral drug delivery provides a convenient way for delivering drug to the posterior segment of the eye. We tested rapidly polymerizing collagen-based slow release delivery system which is non-toxic, minimally invasive, and highly customizable towards different therapies. We examined this delivery system with POT-4, a strong complement inhibitor peptide currently in clinical trials for the treatment of AMD. In order to determine the optimum collagen formulation, we studied in-vitro release of POT-4 from different collagen formulations and tested whether POT-4 released from gel is still active. We also measured in-vitro release of POT-4 from a collagen gel for 6 weeks to ascertain the optimum collagen formulation. Pharmacokinetic studies are currently underway to study in-vivo release of POT-4 after transcleral injection of optimum collagen formulation mixed with POT-4.

Results: : Among the different collagen formulations tested, rapidly polymerizing collagen type I was the most promising formulation for POT-4 delivery. Release of POT-4 from collagen gel is bi-phasic with an initial burst followed by sustained release.

Keywords: age-related macular degeneration • development