In this study we tried to develop a new approach to suppress
inflammation and neovascularization in the
alkali-injured rabbit cornea. For this reason
Cyclosporine A (CsA)-loaded electrospun nanofibers were transferred onto the ocular surface injured with
alkali (0.25 N NaOH). Damaged corneas were divided into the following groups: untreated, treated with CsA
eye drops, treated with nanofibers
drug-free and treated with CsA-loaded nanofibers. Healthy rabbit corneas served as controls.
Drug-free nanofibers and CsA-loaded nanofibers were transferred onto the damaged corneal surface immediately after the injury and sutured to conjunctiva. On day five after the injury the nanofibers were removed. The animals from all groups were sacrificed on day twelve after the injury. The extent of the inflammatory reaction and corneal healing were examined macroscopically, immunohistochemically and biochemically. The central corneal thickness was measured using an ultrasonic pachymeter. When compared with untreated injured corneas, injured corneas treated with
drug-free nanofibers or injured corneas treated with CsA
eye drops, the number of CD3-positive cells (T lymphocytes) and the production of pro-inflammatory
cytokines were strongly reduced in corneas treated with CsA-loaded nanofibers, which was associated with the significantly decreased expression of
matrix metalloproteinase 9,
inducible nitric oxide synthase,
vascular endothelial growth factor and active
caspase-3. CsA-loaded nanofibers effectively suppressed corneal
inflammation and
corneal neovascularization. Central corneal thickness restored to levels before injury only in corneas treated with CsA-loaded nanofibers. Corneal transparency was highly restored in these corneas. It is suggested that the beneficial effect of CsA-loaded nanofibers was associated with the continuous release of CsA from nanofibers and continuous affection of damaged cornea by CsA. The
suture of nanofibers to conjunctiva and the closed eyes contributed to beneficial corneal healing. This is in contrast to CsA
eye drops, which are quickly washed from the ocular surface and the contact of CsA with the damaged cornea was limited. In conclusion, the approach with CsA-loaded nanofibers could represent an effective alternative mode of
therapy for corneal
chemical burns.