The Mouse That Changed the World of Science

ur world had seen major advancements in the scientific industry during the 20th century. People at the time knew that as technology advances so will medicine to the point where every part of the human body will be grown externally and replaced just like the parts of a broken machine. Although these scientific theories have been debated for decades, no one was quite ready to see them happen.

The world was taken by surprise when all the news outlets shared the photo that you are seeing above in 1997. Some were excited, most were scared and the rest were outraged due to the ethical implications of such experiments. A backlash of protests against genetic engineering started in the western world.

What the world misunderstood is that this experiment had nothing to do with genetic engineering. Part of the blame for this misinformation goes to some of the news outlets that used such keywords to promote this photo when they didn’t know much information behind the actual experiment that started almost 10 years prior to the photo.

The need for an ear

Plastic surgery evolved a lot during the last part of the 20th century, but even so, the human ear remained the most difficult part of the human body to reconstruct because of the cartilage it is made out of. Although cartilage could be created, it was very difficult to make it out of human tissue, therefore many people who had accidents involving their ears would have to live with a shapeless ear or no ear forever.

This problem gave birth to the mouse-ear project in 1898 led by Charles Vacanti, an expert in tissue engineering and stem cells. During the same year, Charles Vacanti with the help of his brother Joseph Vacanti (an expert in tissue reconstruction) managed to grow a small piece of human cartilage on a biodegradable scaffold.

When the photo of the mouse came out everyone thought that the DNA of the mouse was genetically engineered to grow a human ear on its back, but there was no genetic engineering involved in this experiment, it was something a lot more difficult. The organism of the mouse was not overtaken by human DNA as some protestors had stated, here is actually what happened.

The scaffold was made out of a synthetic material called polyglycolic acid which was commonly used in plastic surgeries. This material would dissolve into carbon dioxide and water once the tissue started to grow back in the affected area. The fibers of this material were molded into a loose mesh in the shape of an ear. With the integrity of 97% air, it left plenty of space to be filled by cells.

As simple as it sounds, this process took about 8 years until it was ready to be placed into an organism to be grown. Attaching it to human tissue would not work as it would not regenerate quickly enough before the cartilage would start dissolving. Another issue was that all immune systems in every organism would identify this cartilage as a foreign body and would try to neutralize it.

A special mouse

The mouse that was used for this experiment was what they called a “Nude Mouse” because it had no hair. This was due to a random mutation that this species suffered which left them with no hair and no immune system. The hair didn’t make much of a difference, but the lack of an immune system is what made this mouse special and perfect for the experiment.

With no immune system to combat the foreign body, the molded cartilage would be able to be filled with cells until it would fully develop into a human ear. There was no need specifically for human cells, as long as the cells were healthy and developing quickly enough. The synthetic ear cartiladge was created to reproduce the ear of a 3-year-old child, which once transplanted would further develop as the child grew.

The synthetic ear cartilage was surgically placed on the mouse’s back and left there for 12 weeks until it had fully developed with living cells. The ear came close to being 90% similar to a natural human ear which was something very surprising taking into consideration that this experiment didn’t involve any genetic engineering with human DNA.

When the journal paper written by the Vincent brothers came out in 1997 (including photo evidence) the world was frightened for the wrong reasons, as they didn’t bother to actually read the paper to understand how this procedure was done. The ear was later transplanted into a child with success.

For those that would want to see the vincent mouse moving here is a video from 1997.

Despite misunderstandings, this opened the eyes of people to the possibilities of the medical and scientific world. People understood that the future would surpass science fiction movies and this is proven today with patterns of printing ears using 3D printers and with a material created using human cells. If this is happening today, what awaits us in another 20 years? (leave your thoughts in the comment section).