Use of New Biomaterials with Amniotic Membrane Growth Factors in Corneal Regeneration in Vivo

AbstractPurpose: To compare the effect on corneal healing of two novel hydrogels releasing proteins obtained from amniotic membrane (AM).Methods: Forty‐four New Zealand White rabbits underwent corneal wounding with NAOH 1 M and received different treatments: Control (group 1), AM transplantation (group 2), model A hydrogel (group 3) and model B hydrogel (group 4). The progression of wound healing was recorded with photographs and assessed by measuring the remaining epithelial defect over time. Histology was performed to examine acute and chronic changes.Results: There were no statistically significant differences between groups in epithelial defect areas (mm2) at days 0, 7, 14, 21 and 28. The percentage of wound closure (%) showed statistically significant differences on day 7 between Group 1 and Group 4 (p = 0.03). The percentage of completely healed corneas showed no statistically significant differences between the control and treated groups on days 14, 21 and 28, but on day 7, there were differences between Group 4 and Control (p = 0.02). On days 14 and 21 the rate of completely healed corneas was higher in Group 3 and Group 4 (55% on day 14 and 30% on day 21) compared to Group 1 (44.4% on day 14 and 11.1% on day 21).Conclusions: The novel biodegradable hydrogels with AM proteins could promote corneal re‐epithelialization. The chosen animal model showed a high rate of wound reopening once closed. Group 4 hydrogels showed low adhesiveness so the implant movement and the fragile regenerated epithelium could justify the higher de‐epithelized areas on day 7. The results show a higher number of wounds with complete epithelialization and a smaller epithelial defect area (mm2) in the treated groups compared to control, even after removal of the AM proteins, which might indicate that proteins secreted in the early stages of epithelialization could enhance corneal wound closure.