Novel nanopolymer RNA therapeutics normalize human diabetic corneal wound healing and epithelial stem cells.

Human diabetic corneas develop delayed wound healing, epithelial stem cell dysfunction, recurrent erosions, and keratitis. Adenoviral gene therapy modulating c-Met, cathepsin F and MMP-10 normalized wound healing and epithelial stem cells in organ-cultured diabetic corneas but showed toxicity in stem cell-enriched cultured limbal epithelial cells (LECs). For a safer treatment, we engineered a novel nanobiopolymer (NBC) that carried antisense oligonucleotide (AON) RNA therapeutics suppressing cathepsin F or MMP-10, and miR-409-3p that inhibits c-Met. NBC was internalized by LECs through transferrin receptor (TfR)-mediated endocytosis, inhibited cathepsin F or MMP-10 and upregulated c-Met. Non-toxic NBC modulating c-Met and cathepsin F accelerated wound healing in diabetic LECs and organ-cultured corneas vs. control NBC. NBC treatment normalized levels of stem cell markers (keratins 15 and 17, ABCG2, and ΔNp63), and signaling mediators (p-EGFR, p-Akt and p-p38). Non-toxic nano RNA therapeutics thus present a safe alternative to viral gene therapy for normalizing diabetic corneal cells. Schematics of nanobioconjugate action on diabetic cell and corneal wound healing and epithelial stem cells. Left, effects on cultured LEC: the lead NBC causes faster wound healing than control NBC without therapeutic AON. Stem cell marker expression is increased. Right, similar effects are observed on epithelial wound healing and limbal stem cells in organ-cultured diabetic corneas. [Display omitted] • New nanopolymers with covalently attached antisense RNA therapeutics and cell-targeting antibody were synthesized and characterized. • Nanopolymers inhibited diabetic corneal targets cathepsin F and MMP-10, and boosted c-met expression in human cultured progenitor cells and corneas. • Nanopolymer treatment of cultured progenitor cells and corneal organ cultures accelerated wound healing and stem cell marker expression. • Non-toxic and biodegradable nano RNA therapeutics may be useful for alleviating signs of diabetic eye disease. [ABSTRACT FROM AUTHOR]