Abstract
Purpose :
Retinal deterioration affected by an inherited degenerative disorder or loss of acquired visual function due to progressive loss of retinal cell function was reported, and gene therapy can only cure that. Recently, the pharma and bio-compound drug industry has been focused exclusively on gene delivery into target inner tissues such as the retina, pigment cells, and macula region. However, these cure points are not visualized by objective results. Thus, we initially performed gene delivery therapy experiments under the living body through intravital microscopy (IVM).
Methods :
We prepared the 9-week-old Wistar rats as ten animals divided into control and treatment per 5 animals. Then, we designed an amount of recombinant adeno-associated virus-endogenous green fluorescent protein(rAAV-GFP), approximately 6.27 x 108 infectious particles (IPs) per 1 mL of solution with a ratio of 361.88 total particles to each infectious particle for retina objective gene distribution imaging result through by IVM. We performed intravitreal injection with the rAAV-GFP drug to induce the gene delivery. In addition, we acquired the retina imaging following time points on day 2, day 4, day 6, and day 13. Also, we capture the 5~6 imaging spot for output significant data treated by intravitreal injection. All the imaging data was stained with the fluorescence signal as GFP.
Results :
As a result, we can obtain intravital imaging for rAAV-GFP delivery into the retina under a mouse's living body and measure the gene delivery efficiency time as Tmax. Retinal imaging lets us demonstrate how genes are delivered from the optic disc to a distant area. Also, the rAAV-GFP delivery modality showed the difference in each animal following repetitively captured images. Then, these modalities were getting bright fluorescence signals near retinal blood vessels until 13 days after intravitreal injection. These data indicate more accurate efficiency time without sacrificing the experimental animals (2weeks).
Conclusions :
Taken together, IVM retinal imaging in rats within two weeks can more accurately the gene delivery monitoring in the eye disease into ophthalmology. In vivo, retinal imaging in this system may be a noninvasive and advantageous approach to monitoring gene expression in the retina over time.
This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.