Fig 2: Schematic illustration of IGF1@hAMgel as a topical bioactive ECM hydrogel platform that integrates sustained IGF-1 delivery with amnion-derived matrix cues to promote corneal epithelial regeneration, collagen remodeling, immune modulation, nerve repair, and suppression of fibrosis and neovascularization in a rat corneal alkali burn model.

Fig 3: Fabrication, characterization, and ocular retention performance of the temperature -responsive hAMgel.A.Photograph of the human amniotic membrane in its native sheet form.B, C. Macroscopic appearance of the hAMgel precursor solution at room temperature (B, fluid state) and after in situ gelation at 37 °C (C, hydrogel state). D. Comparison of hAMgel transparency after gelation at 37 °C using two precursor concentrations.E. Representative scanning electron microscopy (SEM) images showing the nanofibrous and porous microstructure of hAMgel(4 and 8 mg/mL), mimicking the native extracellular matrix.F.SDS-PAGE showing markedly distinct banding patterns between native human AM and hAMgel.G. Rheological characterization: (a) Shear-thinning behavior confirming injectability of both 4 and 8 mg/mL formulations. Temperature-dependent sol-gel transition showing gelation temperature below 37 °C for both (b) 8 and (c) 4 mg/mL formulations. Elastic modulus-time curves((d) for 8 mg/mL,(e) for 4 mg/ml)and viscosity-time curves ((f) for 8 mg/m,(g) for 4 mg/m) showing temperature-triggered gelation at 37 °C. (h)Frequency sweep at 37 °C showing stable elastic gels (G′ > G″) maintaining integrity below 10 Hz.H. In vitro degradation profiles of hAMgel in (a)PBS, artificial tear fluid, and (b)collagenase I.I. In vitro release profile of IGF-1 from the IGF1@hAMgel.J. Corneal IGF-1 concentration after topical administration of IGF1@hAMgel in rats.K. Representative in vivo fluorescence images of rat eyes at selected time points after topical administration of DiR-labeled formulations (DiR solution, DiR + IGF-1, DiR + hAMgel, DiR + IGF1@hAMgel).