3D artificial cornea: Chula researchers advance canine corneal treatment

The innovation helps to solve the problem of treatment methods that rely on tissue replacement which is hard to find and very expensive.  It makes it possible for dogs to be able to see clearly and comfortably once again.

Does your dog have any of these symptoms?  The inability to fully open its eyes, squinting or blinking frequently, shedding lots of tears, sometimes the tears are thick, and the mucus appears greenish.  The sclera is unusually red and not clear like before.  The cornea becomes cloudy and there are blood vessels in it.   

If your answer is “yes” then your pet might be suffering from a corneal ulcer which, if left untreated could eventually cause blindness.   

Nowadays, the number of dogs receiving treatment for corneal ulcers has increased tremendously.  The small animal hospital at the Faculty of Veterinary Medicine, Chulalongkorn University alone is already treating dogs with corneal ulcers daily.   

“We find quite several lesions like this in dogs.  Corneal ulcers occur as a result of many reasons, such as dogs scratching their own eyes because they have allergies causing itching around the eyes followed by scratching until the lesions form.  Fights with other dogs, being scratched by a cat, or accidentally bumps into objects” Veterinarian Dr Chutirat Torssahakul of the Department of Internal Medicine, Faculty of Veterinary Medicine, Chulalongkorn University addressed the problems that became the starting point for the research and innovation development.  “Three-dimensional artificial cornea from stem cells” enables your beloved pet to have perfect vision once again.  “The current treatment being used is to have grafts made from replacement tissue derived from porcine bladder or canine placentas which are rare and relatively expensive.  There is also the possibility of causing post-surgery reactions and inflammation.  Therefore, we thought that if we could produce our innovative artificial cornea using natural materials that are easily found and reduce the chance of causing inflammation this might be a better option.”  Dr Chutirat explained.    

Three-dimensional artificial cornea from stem cells – a brighter alternative 

As a result of the effort and intention to solve eye problems for dogs, the Faculty of Veterinary Science’s research team through the Veterinary Stem Cell and Bioengineering Innovation Center (VSCBIC) has therefore embarked on additional studies on stem cells and is working with the Biomedical Engineering Research Center of the Faculty of Engineering, Chulalongkorn University recognizing its expertise in tissue engineering to help make adhesive materials for growing stem cells. 

According to Veterinary Professor Dr Chutirat “Artificial corneal tissue is obtained by cultivating real dog corneal stem cells on a natural material structure made from silk fibroin mixed with gelatin.  The material can be cheaply and easily found in Thailand.  It is strong and durable, clear and transparent, and adheres well to cells making them three-dimensional which is comparable to real corneal tissue.” 

This innovation can be used to treat corneal perforations in dogs as well as large corneal wounds where the tissue cannot be stitched or even deep wounds in which a large amount of corneal tissue has been lost.  In cases of dogs with mild or moderate levels of corneal ulcer problems, currently, 2 methods for treatment are still in use.   

1.     Treatment with topical eye drops is usually used in cases that are not too severe, such as a superficial wound or a bit deeper layer. Treatment with eye drops can help prevent complications due to secondary infections.  The drops do not help, however, with healing wounds since that depends on the dog’s body mechanisms. If the body is strong and there is normal cell growth, then most cases will recover on their own.  

2.    Treatment with surgery is used in cases of very deep wounds, complicated wounds, reaching the last layer of the cornea, or penetrating wounds where it is still possible to stitch the corneas together normally. 

“But in cases where the wound in the cornea is so large that tissue must be used to replace the missing part, we usually use a graft which could be the dog’s conjunctiva.  The other option is to use replacement tissue such as tissues derived from human or canine placentas.  These are costly and difficult to find so we have invented a new way to treat them and that is the three-dimensional artificial cornea made from stem cells.” 

4 outstanding features of the 3D artificial cornea innovation  

1.     It appears very similar to the real corneal surface – Research shows that stem cells grown in the lab can create tissue cells.  The extracellular matrix is interconnected and the outline is similar to the real corneal surface.  In particular, the arrangement of stem cells in the cornea is remarkable in that it is more orderly than other positions.  This will help maintain the clarity of the cornea compared to other alternative materials currently in use that are somewhat opaque.  

2.    It derives entirely from all-natural substances- The stem cells used are those that have been harvested from the cornea of the dog being treated or collected from recently deceased corpses so there is little chance of post-transplantation inflammation or irritation.  The structure for cells to adhere to is made from silk fibroin mixed with gelatin.   As time passes, stem cells create their network of cells that form three-dimensional pieces even though the structural materials are naturally degraded by enzymes. 

3.    They can be trimmed during the transplantation process – since the parts are three-dimensional sheets they can be trimmed to fit the wound where the cornea is missing.    

4.    Wounds heal faster – stem cells are living cells and have properties that help in network formation causing cell adhesion.  They also help with strengthening and building collagen so that wound healing can occur.  This is different from using graft sheets that do not contain living cells.    

At present, the “3D artificial cornea from stem cells” innovation is still in the laboratory testing stage to study whether the 3D artificial cornea can be used as a cornea replacement, and to determine how it interacts with the animal’s body.  According to Veterinary Professor Dr. Chutirat in many countries research on such innovations is also currently underway at the laboratory level. 
“The research we have done has produced satisfactory results.  It is expected that this innovation will be applied to dogs in the next few years.  Moreover, we have plans to apply this knowledge to cats as well from cell collection, locating cells, separating cells, and arranging cells” Dr Chutirat concluded.   
Those who are interested can further read the research paper on the subject at https://pubmed.ncbi.nlm.nih.gov/35120168/