Abstract
Purpose :
There remains a major clinical need for ways to overcome the shortage of cadaveric donor tissue needed to surgically treat corneal blindness worldwide. Our goal is to engineer matrix therapy that stabilizes deep corneal wounds and promotes epithelial regeneration and stromal remodeling without the need for a catalyst, light-activation, sutures, or donor tissue.
Methods :
We have developed crosslinked matrices of collagen as well as collagen and hyaluronic acid that form under ambient conditions through strain promoted azide-alkyne cycloaddition (SPAAC), a bio-orthogonal form of copper-free click chemistry, after being applied to deep corneal wounds without the need for a catalyst or light energy source. In vitro cell culture, ex vivo organ culture, and in vivo rabbit corneal keratectomy models were used to evaluate the biologic activity of the gel constructs out to 2 months post-operatively. Slit lamp exam, fluorescein staining, anterior segment optical coherence tomography, pachymetry, tonometry, and immunohistochemistry were used to evaluate the corneas post-treatment.
Results :
Collagen and collagen-hyaluronic acid gels crosslinked by SPAAC form in situ within minutes when applied to deep keratectomy wounds under ambient conditions without the need for a catalyst or light energy. We found that the hydrogels could be cured under an air interface or under a bandage contact lens, and could restore the smooth outer curvature of a keratectomized cornea. SPAAC crosslinking yielded gels that support multi-layered surface epithelialization, tight junction formation, new basement membrane deposition, and normal IOP and corneal thickness, and complete matrix remodeling at 2 months.
Conclusions :
Bio-orthogonally crosslinked gels form in situ on corneal wounds under ambient conditions through copper-free click chemistry without the need for an external catalyst or light energy source. The gels support surface epithelialization and stromal remodeling out to 2 months, which suggests their promise as a therapeutic matrix for suture-free reconstruction of deep corneal wounds.
This is a 2021 ARVO Annual Meeting abstract.