Characterization of a Novel Collagen Scaffold for Corneal Tissue Engineering

Globally millions are blind due to corneal disease, yet tissue for transplantation is a limited resource. This study characterizes the physical and biological properties of a novel collagen-based scaffold. Transparency, optical coherence tomography (OCT), and scanning electron microscopy (SEM) were used to analyze the structure of the scaffold, synthesized using rat tail collagen I. Water content was determined. The tensile strength was assessed using a micro-mechanical analyzer. In vitro biocompatibility was assessed by culturing the scaffold with epithelial or keratocyte spheres. The mean scaffold transmittance was 0.72 at 358 nm, 0.88 at 570 nm, and 0.92 at 900 nm. OCT imaging confirmed that the scaffold maintained a corneal shape, with a central thickness of 502 μm and a reflectivity profile comparable to that of a normal human cornea. SEM of the scaffold revealed multiple lamellae on cross section. The mean water content was 88.7% ± 0.7%. Ultimate tensile strength for the noncross-linked scaffold was 1.23 ± 0.27 MPa compared with 2.21 ± 0.70 MPa for the cross-linked scaffold (human corneal anterior stroma 1.53 ± 0.86 MPa) at a strain rate of 0.5%/s. Epithelial cells migrated over the scaffold to confluence. Keratocytes populated the scaffold and maintained a lamellar arrangement. The properties of this novel scaffold suggest that it has potential to be developed into a corneal tissue substitute for human transplantation.