Engineering of a biomechanically and biologically improved amniotic membrane using nanofibrous bacterial cellulose for healing of corneal defects

Despite the low mechanical strength and fast degradation of amniotic membrane (AM), it widely been used as corneal wound dressing for years. To overcome these limitations, we used AM with bacterial nano-cellulose (BC) to fabricate a bilayer membrane with improved biomechanical properties and restorative of corneal epithelium defects. The AM/BC bilayer scaffold was examined in vitro and in vivo for cytobiocompatibility, biomechanical strength, antibacterial properties, and corneal damage regeneration. The results affirmed a considerable improvement in mechanical strength of AM/BC, especially in wet conditions. In addition, this transparent scaffold had excellent cytobiocompatibility and cell attachment properties for corneal epithelium cells and exhibited significant reduction in the degradation rate. Histological examinations revealed that corneal defects treated with AM and AM/BC were fully re-epithelialized by days 7 and 21. In contrast, control wounds remained ruptured and showed collagen deposition after 21 days, while reductions in collagen synthesis were noted in the treated areas. Of note, the expression of the genes associated with corneal healing was upregulated in the wounds, confirming superior wound healing with minimal inflammation in AM and AM/BC compared with the control. Our data demonstrate the therapeutical potential of AM/BC as an excellent corneal scaffold for human corneal wounds.