Non-viral vectors
Some inherited retinal diseases (IRDs) can be treated by the administration of nucleic acids to the back of the eye. To help these nucleic acids to enter cells and to protect them from degradation, they need to be encapsulated into nanoparticles. Viruses can be used to deliver these nucleic acids, but some nucleic acids are too large to fit into small viral particles. Therefore, we will explore non-viral particles, made out of lipids, to encapsulate large nucleic acids (Figure 1, A). Using a special fluorescence based technique (Fluorescence Correlation Spectroscopy, FCS) we can count the number of nucleic acids per nanoparticle. Furthermore, we can determine if these particles can be used for intravitreal injection. Important characteristics are the possible release of nucleic acids from the nanoparticles, the mobility of the nanoparticles in the vitreous and the protection of nucleic acids against enzymatic degradation. These experiments can be performed in isolated bovine eyes (Figure 1, B). Finally, we can use microscopy to see if the nanoparticles that were injected in the vitreous can reach the retinal cells, which are shielded from the vitreous by the thin but very difficult to cross Inner Limiting Membrane (ILM) (Figure 1, C). These experiment will help to optimize non-viral nanoparticle mediated delivery of large nucleic acids to retinal cells, after the more safe and less invasive intravitreal administration.
