Self-Assembling Peptide Nanofiber Hydrogel as 3D Scaffolds for Corneal Stromal Cells

The leading causes of corneal damage are keratoconus, Fuchs endothelial dystrophy, keratoconus, and corneal ulceration. Once corneal damage causes visual impairment or blindness, cornea transplantation is the best treatment option to restore vision. Corneal tissue engineering provides an alternative to corneal transplantation to overcome limited donor tissue availability and drawbacks of transplantation. However, the complex mechanical, structural, and optical properties of the cornea make tissue engineering a challenging application. The expected properties of a corneal tissue-engineered scaffold include water permeability, optical transparency, and mechanical strength along with biodegradability, biocompatibility, and porosity. Some of these properties such as superior optical transparency and biocompatibility can be provided by peptide-based hydrogels. In this study, two different self-assembled peptide hydrogels are investigated for corneal stromal tissue engineering. Both MAX8 and RADA16-I peptides convert into β-sheet-forming hydrogels at high ionic strength and physiological pH. &lt;div&gt;Additionally, MAX8 peptides are modified with three different peptide ligands to enhance cell adhesion and inhibit neovascularization in the scaffold during stromal regeneration. The peptide hydrogels demonstrated proper optical transparency between %90 and %100 and refractivity of 1,337 mimicking natural corneas while maintaining 3D structure for corneal stromal cell proliferation. Hydrogels made up of MAX8 exhibited 40 ±1 Pa, 35,68 Pa, and 78,20 Pa average crossover modulus with different biomarker ligands and RADA8 showed similar results. The gel recovery was also observed after 10 μN constant shear stresses were applied to both hydrogels. On the other hand, human stromal keratocytes continued expressing cell-specific markers, collagen-I and keratocan, in both hydrogel formulations indicating their potential applicability.<br/><i>This work is funded by 2232 International Fellowship for Outstanding Researchers Program of TÜBITAK (Grant number 118C371). The funder had no role in study design, data collection or analysis, the decision to publish, or the preparation of this abstract.</i>