Engineering of Human Corneal Endothelial Grafts

DESCRIPTION provided by applicant The corneal endothelium plays a pivotal role in maintaining corneal transparency Unlike in other species the human corneal endothelium is notorious for its limited proliferative capacity in vivo after diseases injury aging and surgery Persistent corneal endothelial dysfunction leads to sight threatening bullous keratopathy Presently the only solution to restore vision in eyes inflicted with bullous keratopathy relies upon transplantation of a cadaver donor cornea containing a healthy corneal endothelium Due to a severe global shortage of donor corneas in conjunction with an increasing trend toward transplanting only the corneal endothelium in procedures collectively termed andquot endothelial keratoplasties andquot it is timely and paramount to develop a tissue engineering strategy to produce surgical grafts containing human corneal endothelial cells HCECs Using our reported in vitro model system in which the mitotic block is mediated by contact inhibition when cell junctions mature we have shown that the conventional engineering methods using EDTA bFGF to generate single HCECs activates catenin Wnt signaling and the loss of the normal HCEC phenotype to endothelial mesenchymal transition EMT In contrast our novel engineering method based on transient knockdown by p catenin p and Kaiso siRNAs unlocks the mitotic block by activating p Kaiso signaling but not catenin Wnt signaling We have further optimized this p Kaiso knockdown regimen by switching to a serum free medium containing bFGF and LIF and discovered that our method further activates RohA ROCK canonical BMP signaling to reprogram HCECs to neural crest like progenitors which proliferates to maintain the normal HCEC phenotype without EMT Consequently our novel tissue engineering technology can successfully produce from Descemet membrane stripped from of the corneoscleral rim normally discarded after conventional corneal transplantation one HCEC monolayer with a hexagonal shape comparable in vivo cell density and an average size of mm in diameter That is the technology will add at least an additional transplantable grafts per one donor cornea In this Phase II application we propose to establish reproducible GMP engineering of HCEC grafts on an implantable collagen membrane with a new packing system to transport these grafts Aim and to examine the safety and efficacy of these engineered HCEC grafts through the surgical procedure of DMEK in an in vivo NIH mini pig model of endothelial dysfunction Aim Completion of these two Aims will allow the Company to gather sufficient pre clinical data needed for an IND submission to the FDA Ultimately the Company can capture a unique market opportunity by fulfilling an unmet global need One day this new tissue engineering technology can also be deployed to engineer other similar monolayer tissues such as retinal pigment epithelium RPE for submacular transplantation in treating retinal blinding diseases characterized by dysfunctional RPE Furthermore successful commercialization of this technology will stimulate the scientific community to re think how andquot contact inhibitionandquot can safely be perturbed to our benefit i e by maintaining the normal phenotype and whether this new regenerative approach can circumvent the need to reprogramming directly from embryonic stem cells or induced pluripotent stem cells PUBLIC HEALTH RELEVANCE This Phase II application proposes to develop a novel strategy of engineering human corneal endothelium based on selective activation of p catenin Kaiso RhoA ROCK canonical BMP signaling using interference RNA technology targeted at p catenin and Kaiso During Phase I we gathered strong preliminary data supporting the plausibility of further expanding human corneal endothelial monolayers by optimizing the knockdown regimen in a serum free medium containing bFGF and LIF to generate at least transplantable HCEC monolayers from one donor rim Successful completion of the Phase II project will allow the Company to gather sufficient pre clinical data fo an IND submission to the FDA so we can capture the commercial value of this new tissue engineering technology to fulfill a global shortage of donor cornea for restoring sight in patients suffering from bullous keratopathy due to dysfunctional human corneal endothelium