Multimodal high-resolution imaging of photoreceptor precursor cells using gold nanoparticles

Cell replacement therapy is a feasible approach for vision restoration in several degenerative diseases of the outer retina in order to halt disease progression and recover lost vision. In this treatment photoreceptor precursors are transplanted in the subretinal space and later integrate within the retina. In order to evaluate the efficiency of cell transplantation for vision restoration, it is crucial to monitor cell survival and integration in the host retina over extended periods, therefore, longitudinal tracking of the transplanted cells in clinical and experimental setups is crucial. Here we present a technique for labeling photoreceptor precursors with gold nanoparticles prior to vitreous and subretinal space transplantation treatment. This labeling allow multimodal imaging using both computed tomography (CT), optical coherence tomography(OCT) and fluorescence fundus imaging. Our multimodal imaging technique enabled high-resolution longitudinal tracking of the transplanted cells for over a month, and quantification of cell survival in the retina and vitreous, without any toxic effects. These findings promote the use of nanoparticles for retinal cell tracking and its translational potential providing more efficient cell replacement therapies for clinical applications.