| Tissue engineered corneal implants provide an alternative for patients who do not respond favorably to donor corneas. The most common challenge of current artificial corneas is their lack of integration with host tissue that can lead to infection, tissue necrosis (melting) or spontaneous rejection (extrusion). These synthetic devices lack cell adhesion cues to promote host cell ingrowth. In response, natural materials have been investigated as cell adhesive scaffolds. However, these typically require toxic crosslinkers to impart sufficient mechanical strength. We have engineered a hybrid scaffold of natural and synthetic materials by utilizing superporous technology to efficiently incorporate cells and other natural matrix materials in a stable synthetic hydrogel.The superporous hydrogel (SPH) swells rapidly in solution due to large and interconnected pores. Therefore uptake of liquid into the scaffold is very quick, based on capillary action rather than diffusion. Cells, proteins, and other ECM molecules can be incorporated into the superporous hydrogel (SPH) in this simple manner without requiring external forces. To mimic truly 3-D physiological environments, we have embedded cells within type 1 collagen (a ubiquitous stromal matrix protein) prior to uptake by the SPH. This creates a 3-D collagenous microenvironment that enhances cell adhesion while maintaining mechanical integrity. We have also shown that this scaffold enhances cell migration into the scaffold even if cells are not preseeded in the scaffold. This biocompatible, porous, cell-based, tissue engineered cornea will provide a more effective and long term alternative therapy for many patients with corneal blindness. |
