Abstract
Purpose :
Cell transplant of human corneal endothelial cells (HCECs) is being studied for the treatment of corneal endothelial dysfunction. Delivery and retention of injected cells are crucial for a successful outcome. Previous studies proposed the use of magnetic HCECs in conjunction with an external magnetic patch to localize the injected cells to the endothelium. Here we evaluate the distribution and retention of clinical grade magnetic nanoparticles (MNPs) in HCECs.
Methods :
HCECs were isolated from cadaveric donor corneas and expanded in vitro, alternating between mitogenic and stabilizing media to favor proliferation and morphology, respectively. Prior to harvesting, HCECs were incubated with clinical grade MNPs. We evaluated the effectiveness and stability of MNP incorporation in HCECs via transmission electron microscopy (TEM), scanning electron microscopy (SEM), flow cytometry and passage through a magnetic column.
Results :
The use of clinical grade MNPs yielded ~90% magnetic HCECs, whereas research grade MNPs only labeled 10% of the cells. Use of a magnetic separation system revealed consistency in MNP content across multiple batches. Flow cytometry demonstrated no changes in expression of functional HCEC identity markers. In stability experiments, magnetic HCECs remained highly viable (>90%) and magnetic (>90%) for up to 48 hours. These cells expressed identity and functional markers similar to control HCECs. MNP distribution on the cell surface and inside endosomes was confirmed using TEM and SEM techniques.
Conclusions :
HCECs loaded with clinical grade MNPs are stable, and MNPs have no adverse effect on cell morphology and expression of functional identity markers. Clinical studies using these magnetic HCECs are underway.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.