Using pig cornea to help humans

Story written by: Gudiseva Chandrasekher

Editor’s note: Chandrasekher is an associate professor in the Department of Pharmaceutical Sciences, arriving at SDSU in 2008 from the Kirksville (Missouri) College of Osteopathic Medicine. He has more than 25 years of experience in conducting basic and applied research related to ocular disorders.

Chandrasekher is performing research that could lead to development of cornea-equivalents for transplantation purposes. Corneal transplantation, which is referred to as ‘keratoplasty’ in ophthalmology clinics, is the most common treatment for irreparable corneal damage. In most cases, only the diseased or injured section of the cornea is replaced.

Currently, the supply of implantable quality human donor corneas does not meet the growing demand for transplants. Develop technologies for generating cornea-equivalents is critical to alleviate the dependence on human tissue.

The materials used for the bioengineering of cornea substitute must possess similar chemical and optical characteristics to natural tissue. Chandrasekhar has recently developed a proprietary first-in-class, patented biomaterial named cornea-ECMIX. ECMIX (extracellular matrix proteins) is pig cornea solubilized in its entirety. Most importantly, this liquefied tissue-derived composition contains all components native to the cornea.

As a result of convergent evolution, pigs and humans share certain physiological and anatomical similarities in many organs (i.e., skin, brain, heart). A cornea equivalent rebuilt from ECMIX exhibited optical characteristics (light transmission and refractive index) and cell regeneration capability.

Chandrasekher is pursuing preclinical research to validate the utility of ECMIX-based implants for the repair or replacement of diseased human cornea. The premise is that an implant fabricated from ECMIX is biocompatible, integrates well with the tissue and less likely to cause tissue rejection.

Currently, there is no biomaterial in the market that matches the composition of corneal tissue. In the longer term, liquid cornea ECMIX could serve as bio-ink for 3D printing of full-thickness corneas for transplantation in high-risk patients.

Chandrasekher also is investigating the usefulness of ECMIX technology for the development of a ‘temporary cornea repair’ product for mitigation of combat-related acute corneal trauma.

During combat operations, penetrating objects and debris produced by explosive devices inflict partial- or full-thickness corneal injuries. The U.S. Department of Defense needs a cornea repair device that will temporarily stabilize open eye globes. The device must be an easy to employ nonsurgical technology that forms a watertight seal for maintaining soldiers’ ocular tissue integrity for up to 72 hours in the battlefield emergency (prehospital role of care) facilities before evacuating for definitive care.

Chandrasekher is evaluating ECMIX-based technology for the development of attachable/detachable adhesive film. He believes that this research will lead to creation of a transparent sticky film that offers clear vision to the patient until it is removed following the resolution of inflammation from initial trauma.

Chandrasekher’s cornea-related research has been supported by funds from South Dakota Governor’s 2010 research centers.