Purpose: To determine the safety, survival, and functionality of human embryonic stem cell–derived RPE (hESC-RPE) cells seeded on a polymeric substrate (rCPCB-RPE1 implant) and implanted into the subretinal (SR) space of Royal College of Surgeons (RCS) rats. Methods: Monolayers of hESC-RPE cells cultured on parylene membrane were transplanted into the SR space of 4-week-old RCS rats. Group 1 (n = 46) received vitronectin-coated parylene membrane without cells (rMSPM+VN), group 2 (n = 59) received rCPCB-RPE1 implants, and group 3 (n = 13) served as the control group. Animals that are selected based on optical coherence tomography screening were subjected to visual function assays using optokinetic (OKN) testing and superior colliculus (SC) electrophysiology. At approximately 25 weeks of age (21 weeks after surgery), the eyes were examined histologically for cell survival, phagocytosis, and local toxicity. Results: Eighty-seven percent of the rCPCB-RPE1–implanted animals showed hESC-RPE survivability. Significant numbers of outer nuclear layer cells were rescued in both group 1 (rMSPM+VN) and group 2 (rCPCB-RPE1) animals. A significantly higher ratio of rod photoreceptor cells to cone photoreceptor cells was found in the rCPCB-RPE1–implanted group. Animals with rCPCB-RPE1 implant showed hESC-RPE cells containing rhodopsin-positive particles in immunohistochemistry, suggesting phagocytic function. Superior colliculus mapping data demonstrated that a significantly higher number of SC sites responded to light stimulus at a lower luminance threshold level in the rCPCB-RPE1–implanted group. Optokinetic data suggested both implantation groups showed improved visual acuity. Conclusions: These results demonstrate the safety, survival, and functionality of the hESC-RPE monolayer transplantation in an RPE dysfunction rat model.
Bibliographical noteFunding Information:
The authors thank colleagues Sherry Hikita and Linc Johnson for their valuable contributions in the manuscript and for the technical assistance from Zhenhai Chen, Anthony Rodriquez, Eric Barron, and Xiaopeng Wang. Supported by Grant DR1-01444 from the California Institute for Regenerative Medicine and by the Institute for Collaborative Biotechnologies at the University of California Santa Barbara through Grant W911NF-09-0001 from the U.S. Army Research Office. Supported by an unrestricted departmental grant from Research to Prevent Blindness, New York, New York, United States.
© 2016, Association for Research in Vision and Ophthalmology Inc. All rights reserved.
- Optokinetic testing
- Retinal pigment epithelium
- Stem cells
- Superior colliculus