Every year in the United States, over 33,000 corneal transplants are performed. The success rate for this procedure is fairly high (90% after two years) and although current access to donor tissue is adequate, the quality of tissue varies significantly which influences surgical outcomes. In addition, the proliferation of LASIK procedures, which disqualifies a cornea for transplantation, threatens to reduce the availability of donor corneas in the near future. In recent years, laudable attempts have been made to produce corneal equivalents by tissue engineering. These constructs have proven the concept that three layers of cells, resembling the epithelium, keratocytes and endothelium may be cultured into a collagen matrix. However, such constructs have only met with limited success because the stromal matrix, which provides the cornea with its unique (and critically important) mechanical and optical properties, has not been reproduced. Randomly oriented collagen gels, which represent the typical starting point for tissue engineered corneas, are not likely to be strong enough or clear enough for clinical use. In addition, expecting a significant in vivo remodeling response to integrate a partially functioning artificial cornea is not acceptable. The artificial construct should be functional at the time of implantation. For these reasons, we propose a stromal-centric approach toward the generation of an artificial cornea. We start by investigating precisely how fibroblastic cells produce organized tissue in vitro by tracking human fibroblasts live as they produce matrix on a long-term live imaging culture system. Then by combining bioengineering, biology, biomechanics and biochemistry an attempt will be made to produce biomimetic stromal lamellae (the building blocks for an artificial cornea). The method entails using the intelligence already """"""""encoded"""""""" into the collagen triple helix which produces organized arrays of fibrils simply by concentrating the monomers to induce liquid crystalline structure formation and fibrillogenesis. The resulting organized arrays of fibrils will be used as starting point for comprehensive investigation into the role of matrix molecules on collagen fibril morphology and spacing. Once our arrays are well-characterized, human corneal fibroblasts and human cord blood derived stem cells will be seeded into them and exposed to mechanical stimulation. We expect to induce differentiation in both populations of cells. Completion of this application will provide insight both to the basic science of understanding corneal stromal development and to achieving our ultimate goal, which is the ex vivo generation of a functional, biomimetic artificial cornea from natural components.

Public Health Relevance

Completion of this application will provide insight both to the basic science of understanding corneal stromal development and to achieving our ultimate goal, which is the ex vivo generation of a functional, biomimetic artificial cornea from natural components. Given recent advances in biomaterials engineering and stem cell research (which are combined in this application) we expect to ultimately enhance the ability of clinicians to offer patients with significant morbidity viable alternative treatment options based on engineered tissue.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY015500-06
Application #
7936910
Study Section
Special Emphasis Panel (ZRG1-BDCN-F (02))
Program Officer
Shen, Grace L
Project Start
2004-04-01
Project End
2012-09-29
Budget Start
2010-09-30
Budget End
2012-09-29
Support Year
6
Fiscal Year
2010
Total Cost
$380,333
Indirect Cost
Name
Northeastern University
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
001423631
City
Boston
State
MA
Country
United States
Zip Code
02115
Paten, Jeffrey A; Siadat, Seyed Mohammad; Susilo, Monica E et al. (2016) Flow-Induced Crystallization of Collagen: A Potentially Critical Mechanism in Early Tissue Formation. ACS Nano 10:5027-40
Tonge, Theresa K; Ruberti, Jeffrey W; Nguyen, Thao D (2015) Micromechanical Modeling Study of Mechanical Inhibition of Enzymatic Degradation of Collagen Tissues. Biophys J 109:2689-2700
Paten, Jeffrey A; Tilburey, Graham E; Molloy, Eileen A et al. (2013) Utility of an optically-based, micromechanical system for printing collagen fibers. Biomaterials 34:2577-87
Flynn, Brendan P; Tilburey, Graham E; Ruberti, Jeffrey W (2013) Highly sensitive single-fibril erosion assay demonstrates mechanochemical switch in native collagen fibrils. Biomech Model Mechanobiol 12:291-300
Flynn, Brendan P; Tilburey, Graham E; Ruberti, Jeffrey W (2013) Erratum to: Highly sensitive single-fibril erosion assay demonstrates mechanochemical switch in native collagen fibrils. Biomech Model Mechanobiol 12:847
Wang, Lina; Johnson, Joshua A; Chang, David W et al. (2013) Decellularized musculofascial extracellular matrix for tissue engineering. Biomaterials 34:2641-54
Saeidi, Nima; Guo, Xiaoqing; Hutcheon, Audrey E K et al. (2012) Disorganized collagen scaffold interferes with fibroblast mediated deposition of organized extracellular matrix in vitro. Biotechnol Bioeng 109:2683-98
Mega, Yair; Robitaille, Mike; Zareian, Ramin et al. (2012) Quantification of lamellar orientation in corneal collagen using second harmonic generation images. Opt Lett 37:3312-4
Saeidi, Nima; Karmelek, Kathryn P; Paten, Jeffrey A et al. (2012) Molecular crowding of collagen: a pathway to produce highly-organized collagenous structures. Biomaterials 33:7366-74
Chang, Shu-Wei; Flynn, Brendan P; Ruberti, Jeffrey W et al. (2012) Molecular mechanism of force induced stabilization of collagen against enzymatic breakdown. Biomaterials 33:3852-9

Showing the most recent 10 out of 17 publications