Abstract
Purpose:
This study was designed to evaluate the effects of pirfenidone nanoparticles on corneal reepithelization and scarring, major clinical challenges after alkali burn.
Methods:
Effect of pirfenidone on collagen I and α-SMA synthesis from TGFβ induced primary corneal fibroblast cells was assessed by immunocytochemistry and immunoblotting. Pirfenidone loaded poly (lactide-co-glycolide) (PLGA) nanoparticles were prepared, characterized and their delivery in primary corneal fibroblast cells was examined. Alkali burn was induced in one eye of Sprague Dawley rats (n=18) followed by once daily topical treatment with PBS (n=6), free pirfenidone (n=6), or pirfenidone nanoparticles (n=6) containing equivalent amount of pirfenidone. Corneal re-epithelization was assessed daily by flourescein dye test, absence of stained area indicated complete re-epithelization and the time for complete re-epithelization was determined. Corneal haze was assessed daily for 7 days under slit lamp microscope and graded using standard method (Fantes et al. 1990). After 7 days, collagen I deposition in the superficial layer of cornea was examined by immunohistochemistry.
Results:
Pirfenidone prevented (P<0.05) increased collagen I and α-SMA synthesis by TGFβ induced corneal fibroblasts in a dose dependent manner. Pirfenidone could be loaded successfully within PLGA nanoparticles, which entered the corneal fibroblast within 5 minutes. There was a significant (P<0.05) improvement in corneal re-epithelization and reduction in corneal haze in corneas treated with pirfenidone nanoparticle compared to PBS. Eyes treated once daily with free pirfenidone did not show improvement
Conclusions:
Pirfenidone decreases collagen synthesis and prevents myofibroblast formation. Pirfenidone nanoparticles improve corneal healing and prevent fibrosis. Pirfenidone nanoparticles are of potential therapeutic value in treating corneal chemical burns and other corneal fibrotic diseases. Fantes, FE, Hanna, KD, Waring, GO 3rd, Pouliquen, Y, Thompson, KP and Savoldelli, M (1990). Wound healing after excimer laser keratomileusis (photorefractive keratectomy) in monkeys. Arch Ophthalmol 108: 665-675
Keywords: 482 cornea: epithelium •
765 wound healing •
512 EMT (epithelial mesenchymal transition)