PROJECT SUMMARY/ABSTRACT
As the dome-shaped, transparent outermost part of the eye, the cornea provides the majority of the focusing
power for the visual pathway. When it is damaged due to severe injury or disease, scarring often ensues,
resulting in reduced vision and, in many cases, blindness. In spite of the various types of corneal transplants
that are available, there remains a major clinical need for new modalities to restore transparency to scarred
corneas without donor tissue, which is in short supply worldwide. Corneal mesenchymal stromal cells (c-
MSCs) have known therapeutic effects on corneal scarring and wound healing, but the optimal way to
deliver their benefits to the eye have yet to be determined. We are developing Sutureless, Pro-regenerative,
Anterior Additive Collagen gel KeratopLasty (SPAACKL), a procedure that removes and replaces blinding
corneal scars with a transparent, stroma-like gel matrix containing c-MSCs. After removal of corneal scar
tissue, the material is applied to the defect as a viscous liquid suspension of c-MSCs, forming a crosslinked,
transparent cellularized stromal substitute within minutes that not only recreates the smooth surface
necessary for clear vision but also promotes rapid re-epithelialization. This technology leverages a
crosslinking technology known as copper-free click chemistry that is bio-orthogonal: it does not react with
proteins, cells, or biologic systems of any kind. As such, it can be safely applied to a corneal wound and
around c-MSCs without producing toxic side products, and without the need for light energy, catalysts or
accelerators. Our central hypothesis is that bio-orthogonal crosslinking can improve the regenerative
benefits of c-MSCs by preserving the bioactivity of its encapsulated cargo compared to less specific
crosslinking chemistries that are used currently in corneal surgery. In preliminary work, we have
demonstrated that bio-orthogonally crosslinked gels support the growth of encapsulated stromal cells and
have demonstrated the regenerative capacity of these cell-matrix composites to support rapid, multi-layered
epithelialization both ex vivo and in vivo. Motivated by this data, our first aim is to test the hypothesis that
matrix stiffness, composition, and crosslinking chemistry influence c-MSCs’ viability and secretion of pro-
regenerative factors. Our second aim is to test the hypothesis that encapsulated c-MSCs exert their pro-
regenerative influence on the corneal epithelium primarily through paracrine signaling. Our third aim is to
evaluate the ability of bio-orthogonally crosslinked hydrogels to deliver therapeutic cargo that enhances
epithelial and stromal regeneration through an in vivo keratectomy model. This research will build the
foundational data for eventual clinical translation of a new way to treat corneal blindness without the need
for sutures, light energy, or cadaveric donor tissue, and has the potential to one day help patients avoid the
need for a traditional corneal transplant.