Abstract
Purpose :
During age-related macular degeneration (AMD), certain aspects of the disease, like RPE cell detachment or mechanical stress, can cause overexpression of proangiogenic factors, such as vascular endothelial growth factor (VEGF). VEGF is the main target to slow angiogenesis progression. However, other proteins may also be viable targets. To clarify which proteins might play a role, it is important to see how RPE cells respond during disease progression. Previously, our research group helped explain the effect of RPE cell detachment on angiogenic factors. To further elucidate new targets and increase the efficacy of current treatments, the effect of mechanical stress must be clarified. Understanding this relationship is difficult with current methods, such as animal models or the use of Bioflex plates, as they can be costly or nonrepresentative.
Methods :
A device was custom-made to exert force on a Transwell membrane and cause controlled mechanical stress on primary porcine RPE cells. The device was created to fit within a syringe pump and to contain spherical instruments with different diameters to mimic increasing amounts of mechanical stress. For example, a wider diameter could imitate larger drusen deposits or increased blood vessel invasion. To ensure the device can represent early stages of AMD, finite element analysis (FEA) was used to estimate stress and strain exerted by the device.
Results :
A model of the device was generated using SolidWorks software. A 3D printed chamber allowed spherical instruments with different diameters to be interchanged for experiments. Preliminary FEA results show that the stress and strain exhibited by the device are very low, indicating it will be beneficial in mimicking the start of AMD.
Conclusions :
Models of key aspects of AMD, like RPE detachment and mechanical stress can be created using engineering methods. While previous research showed angiogenic factor secretion was affected by varying levels of RPE detachment, this model will elucidate if similar changes occur with mechanical stress. An enzyme-linked immunosorbent assay and immunocytochemical staining will be used to ascertain how angiogenic proteins are affected when RPE cells experience mechanical stress. Qualitative real-time PCR will be used to study genetic changes. This research will provide more information on how RPE cells respond to another facet of retinal disease and possibly reveal other therapeutic targets.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.