Regeneration of Corneal Stromal Tissue Using Components of Extracellular Matrix

Abstract

Purpose : Extracellular matrix (ECM) bioscaffolds derived from decellularized tissues have been used to promote the formation of site-appropriate, functional tissues in many clinical applications. However, the ability of ECM to influence the course of corneal wound healing has not been elucidated. In this study, we the examined the ability of an FDA-approved ECM scaffold to stimulate regeneration of native transparent stromal tissue in healing corneal wounds.

Methods : Mouse corneal stromal wounds were produced by debridement with an Algerbrush II as previously described (PMC4398334). Pepsin-soluble urinary bladder matrix (UBM) and matrix-bound nanovesicles (MBV) (PMC4928894) were applied to the corneal surface in fibrin gel at the time of wounding. Scar area 14 days after wounding was calculated in masked fashion from ex-vivo light microscope images using FIJI software. Mouse corneal fibrotic gene expression was examined by qPCR. Neutrophil infiltration was assessed by flow cytometry of collagen-digested corneas at 24 hr after wounding. Statistical significance was determined with using a one-tailed Mann-Whitney test using GraphPad Prism software.

Results : Treatment of corneal wounds with a soluble ECM product or with nanovesicles derived from the ECM resulted in reduced visible scarring 14 days after wounding (p<0.001, n=16). Expression of genes associated with tissue fibrosis (tenascin C, smooth muscle actin, collagen III, and SPARC) was significantly reduced in UBM and MBV treated wounds in comparison with untreated wounded tissue. H&E staining revealed histology similar to that of normal corneas in the treated eyes. Unlike treatment with stem cells, however, infiltration of CD11b+/Ly6G+ neutrophils 24 hr after wounding was not suppressed in ECM-treated corneas.

Conclusions : Soluble ECM and MBV isolated from UBM possess the potential to induce regeneration of native transparent corneal tissue during healing of corneal wounds. The immune response in the ECM-treated wounds differs from that observed during stem cell-treatment of corneal wounds (PMC5336198), suggesting a regenerative mechanism distinct from that of stem cell therapy. UBM is approved for clinical use in several applications suggesting that UBM or its derivatives may be appropriate for treatment of human corneal pathologies.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.