Magnetic Human Corneal Endothelial Cell Transplant: Delivery, Retention, and Short-Term Efficacy

Abstract

Purpose Corneal endothelial dysfunction leads to corneal edema, pain, and vision loss. Adequate animal models are needed to study the safety and efficacy of novel cell therapies as an alternative to corneal transplantation. Methods Primary human corneal endothelial cells (HCECs) were isolated from cadaveric donor corneas, expanded in vitro, transduced to express green fluorescent protein (GFP), loaded with superparamagnetic nanoparticles, and injected into the anterior chamber of adult rabbits immediately after endothelial cell or Descemet's membrane stripping. The same volume of balanced salt solution plus (BSS+) was injected in control eyes. We compared different models for inducing corneal edema in rabbits, and examined the ability of transplanted HCECs to reduce corneal edema over time by measuring central corneal thickness and tracking corneal clarity. GFP-positive donor cells were tracked in vivo using optical coherence tomography (OCT) fluorescence angiography module, and the transplanted cells were confirmed by human nuclei immunostaining. Results Magnetic HCECs integrated onto the recipient corneas with intact Descemet's membrane, and donor identity was confirmed by GFP expression and immunostaining for human nuclei marker. Donor HCECs formed a monolayer on the posterior corneal surface and expressed HCEC functional markers of tight junction formation. No GFP-positive cells were observed in the trabecular meshwork or on the iris, and intraocular pressure remained stable through the length of the study. Conclusions Our results demonstrate magnetic cell-based therapy efficiently delivers HCECs to restore corneal transparency without detectable toxicity or adverse effect on intraocular pressure. Magnetic delivery of HCECs may enhance corneal function and should be explored further for human therapies.

Ex vivo expansion and characterization of human corneal endothelium for transplantation: a review

“…On the other hand, direct injection of cells into the anterior cornea avoids the difficulties associated with the preparation and handling of the fragile T-E CE layer. The possibility of applying the cell suspension directly to the recipient's eye to restore CE has been successfully tested in animal [ 72 , 113 ] and ex vivo Tx [ 114 ] models. After cell injection, no adverse effects, such as abnormal accumulation of injected cells and clogging of the drainage channel, increased intraocular pressure, or rejection of cells were detected [ 24 , 115 ].…”

“…After cell injection, no adverse effects, such as abnormal accumulation of injected cells and clogging of the drainage channel, increased intraocular pressure, or rejection of cells were detected [ 24 , 115 ]. After Tx, cell attachment was improved by the recipient being in a prone position [ 72 ], or magnetic attraction of CECs with endocytosed magnetic nanoparticles [ 116 ], which did not appear to impair CEC function and vision recovery [ 31 , 113 ].…”

Corneal endothelium tissue engineering: An evolution of signaling molecules, cells, and scaffolds toward 3D bioprinting and cell sheets

“…Analysis of the adherent cell density 24 h after the placement of the cultured cell dish and rinsing the unattached cells displayed an increase in the density of adherent cells under magnetic influence compared to the density of cells without a magnetic field. Direct injection of loaded cells into the anterior eye chamber of an animal model facilitated the attraction of the loaded cells to stroma and prevented the dispersion of the cells by placing a magnet on the outside of the closed eyelid over the cornea, which increased the transparency and decreased the corneal thickness and edema in the treated animals (Mimura et al, 2003; Mimura et al, 2005; Moysidis et al, 2015; X. Xia et al, 2019). However, several disadvantages are assumed for this method, such as the incompatibility of iron with human cells and the potential increase of intraocular pressure due to blockage of the TM network (Navaratnam et al, 2015).…”

“…The presence of these progenitor cells in the endothelial layer is still a matter of debate (Wahlig et al, 2019). However, a line of evidence has reported the presence of stem‐like cells in the corneal periphery, which have similar characteristics to “Schwalbe's line cells,” they display alkaline phosphatase and nestin (X. Xia et al, 2019). CE damages trigger the ability of proliferation in these cells.…”

Fusogenic liposome-enhanced cytosolic delivery of magnetic nanoparticles

“…[13][14][15] Iron oxide nanoparticles have also shown great promise in the delivery of cell transplant therapies in vivo, which addresses localization, retention, and integration, thereby greatly increasing therapeutic potency and efficacy. [16][17][18][19][20][21] In addition, magnetic particles have also been used to measure the intracellular viscosity of cells. 22 An emerging and exciting application of iron oxide nanoparticles is to manipulate the localization of specic organelles in living cells in order to understand the effect of their distribution and movement on basic cell functions such as growth, differentiation, and homeostasis.…”