Bioengineered corneal endothelial graft using photodegradable device to induce graft-host integration - PROJECT SUMMARY Although the bioengineered human corneal endothelial cell (hCEC) monolayer graft have shown vision recovery in animal models, the hCEC monolayer do not integrate with the host cornea due to suboptimal and non-tunable degradation of the hCEC-carrier biomaterial in the anterior chamber, which provide mechanical support to the monolayer. Thus, whether the transplanted hCEC monolayer will integrate with the host cornea following the complete degradation of the hCEC-carrier biomaterial and remain functional thereafter is unknown. To validate the bioengineered hCEC monolayers, there is a clear need to develop a biomaterial that has tunable-degradation rate in-vivo to evaluate the engraftment of the hCECs, and is mechanically strong so that the biomaterial-film/hCEC-monolayer construct does not break during the transplantation. The previous work of the team has established that the extracellular-topography cues can significantly modulate hCEC responses. The preliminary work of the team has developed photodegradable hydrogel (pdGel), which can be degraded in a tunable manner after transplantation, within hours to weeks, using tissue-penetrative light. Accordingly, the objective of this proposal is to develop a nano-topography pdGel-hCEC monolayer graft, evaluate monolayer integration with host cornea by tuning the in-vivo degradation rate of the pdGel, and validate the hCEC-monolayer function in-vivo. It is hypothesized that the nano-patterned pdGel will enable the growth of hCECs as a confluent monolayer, improve the hCEC monolayer function and stability by inducing the deposition of native-like extracellular matrix (ECM), and the tunable photodegradation of the carrier will improve the engraftment of the hCEC monolayer. The rationale for this project is the evaluation of the engraftment of hCEC monolayer with the cornea and the function thereafter will validate the use of bioengineered hCEC grafts for potential treatment of multiple corneal patients with one donor. Towards the overall objective, in the first aim, the hCEC monolayer growth on the pdGel, photodegradation kinetics, the biocompatibility of the degradation products, and the engraftment of the monolayer will be evaluated in-vitro and ex–vivo. In the second aim, using a high-throughput topography platform, the effect of 253 unique pdGel topographies will be evaluated on the hCEC monolayer functions to identify the optimum graft design. In the third aim, the photodegradation rate will be tuned in-vivo using light exposure to evaluate its effect on the hCEC engraftment. The proposed research is expected to be significant because it will validate the bioengineered hCEC-monolayer graft technology using a new photodegradable biomaterial, and it will develop new biomaterial and nano-topography platform that will have significant applications beyond ocular tissue engineering. The proposed research is innovative because it, (1) uses two-photon lithography approach to develop an innovative, high throughput nano-topography platform, and (2) leverages the photo-decomposition liability of the cyanine dye to develop an innovative photodegradable hydrogel for hCEC engraftment.
