Fabrication of PVA-based transparent composite films by adjusting the pH and hydrolysis for superficial cornea tissue engineering

Aim and Background: One of the main challenges in corneal tissue engineering is the transparency adjustment of alternative scaffolds. In this article, we have made an attempt to achieve the best transparency of PVA/gelatin film by adapting the pH solution and post-treatment of the film to be more hydrolyzed. The effects of acidic and alkaline solutions modified the mechanical properties, transparency, hydrophilicity, solubility, and swelling ratio of these scaffolds Methods: PVA/gelatin films were made by drop casting method. These films hydrolyzed by different concentrations of NaOH (1/2.5/5/6 M) and pH adjustment of these two polymer blends were set up by adding different concentrations of HCl 37% (20, 50, 100 µl/10ml) to their solutions. Results and discussion: The optimal dry film had a maximum tensile stress of 80 ± 0.22 MPa. The resultant composite film has a light transmittance of 90% in the range of 600 to 900 nm wavelength. Human corneal epithelial cells (HCECs) grown on the composite films showed good adhesion and proliferation as shown by the live/dead staining and MTT assay. Conclusion: In summary, the optimal PVA/gelatin film, containing 100 µl HCl and treated with NaOH 5 M NaOH, presents desirable optical, mechanical, and biological properties making it an attractive candidate for the regeneration of cornea.