Development and characterisation of systems for the delivery of an antiscarring molecule (decorin) for use after corneal injury and cutaneous burn

Introduction: Transforming growth factor-β1 (TGF-β1) is a key cytokine that promotes fibrosis after injury in many adult tissues. Here, we hypothesise that delivery of human recombinant decorin (hr-decorin), a natural antagonist of TGF-β1, loaded into gellan-based biomembrane sheet dressings and fluid gel eye drops, prevents cutaneous and corneal scarring after injury. Methods: Gellan-based wound dressings loaded with hr-decorin were characterised for swelling, release profile of hr-decorin, systemic absorption of hr-decorin and human skin reactions. Topical gellan-based fluid gels loaded with hr-decorin were also tested for penetration of hr-decorin into the cornea and aqueous humour (AqH). The effect of hr-decorin on cell migration, differentiation and expression of scar-associated molecules of TGF-β1-stimulated human dermal fibroblasts (HDF) was also evaluated. Results: Gellan-based wound dressings had a high fluid uptake capacity, no adverse reactions on human skin, and sustained local release but no systemic absorption of hr-decorin after application to pig mid-dermal burns. Gellan-based fluid gel eye drops also released hr-decorin over time, which penetrated the cornea and was detected in AqH. The mRNA expression of scar-associated molecules in cultured TGF-β1-stimulated HDF was significantly decreased by hr-decorin, but no changes at the protein level were detected. Conclusion: The results suggest that delivery of Decorin through gellan-based wound dressing and fluid gel eye drop formulations have the potential for translation into therapies for cutaneous and corneal scarring