Abstract
Purpose :
Bruch’s membrane resides in the subretinal tissue and helps to regulate the flow of nutrients and waste between the retinal pigmented epithelial (RPE) and vascular cell layers of the eye. Bruch’s membrane plays a key role in the development of subretinal diseases such as Age-Related Macular Degeneration. Age-Related Macular Degeneration, or AMD, is the degradation of the RPE cell layer, leading to progressive vision loss. Bruch’s membrane plays an active role in the development of AMD. The thickness, brittleness, and permeability of Bruch’s membrane all have a significant impact on the degradation of the RPE cell layer. As the interactions between Bruch’s membrane, the RPE layer, and the vascular layer play a pivotal role in AMD, modeling these layers is a key step in researching potential therapies for AMD and other retinal diseases.
An accurate model of Bruch’s membrane must be proteinaceous, semi-permeable, and nonporous with similar mechanical properties to in vivo Bruch’s membrane while also being able to support both RPE and vascular cell cultures. Many current models of the subretinal tissue utilize inferior models of Bruch’s membrane called Transwells, which are porous, nonpermeable, plastic membranes that are much thicker than a healthy Bruch’s membrane.
Methods :
To create a more accurate model, artificial membranes were synthesized using solubilized hagfish slime proteins. The characteristics of the hagfish membranes were evaluated using mechanical stress testing, permeability assays, and brightfield microscopy. The capacity of the membranes to support ARPE-19 and Human Retinal Microvascular Endothelial Cell cultures was determined using cell staining with brightfield microscopy, fluorescent microscopy, immunocytochemical imaging, and enzyme-linked immunosorbent assays.
Results :
The tests demonstrate the potential of these hagfish protein membranes to accurately replicate Bruch’s membrane in an in vitro model of the subretinal tissue. When compared to existing models of the subretinal tissue, the hagfish membranes demonstrate more mimetic geometric properties, mechanical properties, and permeability characteristics to those of a natural Bruch’s membrane, as well as the ability to support relevant cell cultures.
Conclusions :
The verification of this model will create an opportunity for more comprehensive and accelerated initial testing for potential retinal disease therapies.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.