Three-dimensional cell culture environment promotes partial recovery of the native corneal keratocyte phenotype from a subcultured population.

Corneal disease is the fourth leading cause of blindness. According to the World Health Organization, roughly 1.6 million people globally are blind as a result of this disease.

Design and validation of a corneal bioreactor.

Mechanical strain is an important signal that influences the behavior and properties of cells in a wide variety of tissues. Physiologically similar mechanical strain can revert cultured cells to a more normal phenotype. Here, we have demonstrated that 3% equibiaxial (EB) and uniaxial strains confer favorable protein expression in cultured rabbit corneal fibroblasts (RCFs), with approximately 35% and 65% reduction in expression of α-smooth muscle actin (α-SMA), respectively.

Effect of substrate composition and alignment on corneal cell phenotype.

Corneal blindness is a significant problem treated primarily by corneal transplants. Donor tissue supply is low, creating a growing need for an alternative. A tissue-engineered cornea made from patient-derived cells and biopolymer scaffold materials would be widely accessible to all patients and would alleviate the need for donor sources.

Characterizing the effects of aligned collagen fibers and ascorbic acid derivatives on behavior of rabbit corneal fibroblasts.

The cornea is responsible for functional optical activity of the mammalian eye, as it must remain transparent in order to focus light onto the retina. Corneal disease is the second leading cause worldwide of vision loss [1]. Human donor tissue transplantation in the cornea is associated with problems such as immunorejection and recurring graft failures [1].

Recreating the microenvironment of the native cornea for tissue engineering applications.

A viable tissue-engineered corneal replacement needs to be transparent and mechanically resilient. One necessary element for achieving this level of functionality is a scaffolding material that minimizes backscattered light, supports cellular growth, and maintains the transparent cellular phenotype. We hypothesize that the best scaffolding material will mimic the microenvironment of the natural corneal extracellular matrix (ECM).

The development of a tissue-engineered cornea: biomaterials and culture methods.

The field of corneal tissue engineering has made many strides in recent years. The challenges of engineering a biocompatible, mechanically stable, and optically transparent tissue are significant. To overcome these challenges, researchers have adopted two basic approaches: cell-based strategies for manipulating cells to create their own extracellular matrix, and scaffold-based strategies for providing strong and transparent matrices upon which to grow cells.

Bioreactor design for cornea tissue engineering: Material-cell interactions.

Several materials were evaluated for potential use in a bioreactor system for a tissue-engineered cornea. Two types of cytotoxicity tests were performed using human corneal stromal fibroblasts: a 24h cytotoxicity test based on the ASTM standard F813-01 and a 7 days growth inhibition test. It was determined that culture configuration, autoclaving and materials surface preparation were all important factors influencing cell viability.

Immunogold labeling to enhance contrast in optical coherence microscopy of tissue engineered corneal constructs.

Our lab has used an optical coherence microscope (OCM) to assess both the structure of tissue-engineered corneal constructs and their transparency. Currently, we are not able to resolve cells versus collagen matrix material in the images produced. We would like to distinguish cells in order to determine if they are viable while growing in culture and also if they are significantly contributing to the light scattering in the tissue.

Office-based optical coherence tomographic imaging of human vocal cords.

Optical coherence tomography (OCT) is an evolving noninvasive imaging modality and has been used to image the larynx during surgical endoscopy. The design of an OCT sampling device capable of capturing images of the human larynx during a typical office based laryngoscopy examination is discussed. Both patient's and physician's movements were addressed.

Biomechanical and optical characteristics of a corneal stromal equivalent.

Cell matrix interactions are important in understanding the healing characteristics of the cornea after refractive surgery or transplantation. The purpose of this study was to characterize in more detail the evolution of biomechanical and optical properties of a stromal equivalent (stromal fibroblasts cultured in a collagen matrix). Human corneal stromal fibroblasts were cultured in a collagen matrix.

In vitro culture characteristics of corneal epithelial, endothelial, and keratocyte cells in a native collagen matrix.

The objective of this investigation was to demonstrate the effectiveness of a tissue-engineered collagen sponge as a substrate for the culture of human corneal cells. To that end, human kerotocyte, epithelial, and endothelial cells were cultured separately on collagen sponges composed of native fibrillar collagen with a pore size of approximately 0.1 mm.