There is no doubt that science has made many incredible breakthroughs over the past 100 years. This is especially true for medicine and bioengineering. From life-saving vaccines to revolutionary surgeries, science is making our lives better. To come up with new solutions to age-old problems, progress needs scientists. Behind every medical discovery is a laboratory full of amazing ideas. Sometimes these experiments raise ethical questions. But more often they only lead to interesting solutions to annoying problems.
What's more sophisticated than growing something in the lab from scratch? Here's a list of ten incredible lab-grown pieces put together by Listverse. This you have not seen before!
Pork bones
In 2016, US scientists successfully implanted laboratory-created bones in fourteen adult Yucatan mini-pigs. None of the pigs rejected new organs after surgery. Quite the opposite. The blood vessels of the lab-grown bones seamlessly integrated into the pig's already existing circulation.
How did this even become possible?
First, the scientists scanned the pig's jaw bones and mapped their structures. Then they created suitable cellular scaffolds from cow bones. These structures were injected with pig stem cells and filled with a nutrient-rich solution. The result is fully functional living bone.
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Rat limb
Scientists at Massachusetts Hospital made headlines when they raised an entire rat's front paw in a lab in 2015. This was the first successful project of its kind in the world.
The process was led by Dr. Harold Ott, who also headed the Ott Laboratory for Organ Engineering and Regeneration. After just 16 days, their experiment resulted in the creation of muscle tissue. Here's how they did it.
Dr. Ott and his team took a live rat limb and removed all of its cells. This process is called decellularization. Once the living cells were removed, the scientists were left alone with the protein frame for the limb.
They then filled this structure with living cells, which formed muscle tissue and blood cells in just a few weeks. To test the functionality of a lab-grown limb, the group applied a weak electrical current to muscle tissue.
Result? The muscles in the limb contracted in the same way as if they were normal, grown in organs.
Burgers
The first lab-grown burger, code-named schmeat, appeared in London in 2013. It was created in the Netherlands by Dr. Mark Post, professor of vascular physiology. His goal was to reproduce meat that "does not cause animal suffering and does not harm the environment," unlike traditional meat sources. The project took 5 years and $ 325,000.
It was after the success of Post that the excitement about the creation of laboratory meat began. Memphis Mear, a San Francisco-based startup, created lab meetballs in 2016. Also raised chicken sticks - the first in the world.
However, lab-grown meat is unlikely to be available to the general public until 2021.
Human pig embryo
A team of scientists from Spain and La Joya, California at the Salk Institute have successfully grown human cells in a pig embryo. The goal of the study was to eventually grow entire human organs to be used for transplantation inside other animals. Scientists at Salk have already grown several rat organs inside mouse embryos. But with the latest research, inevitable ethical questions have been raised.
In 2015, the US ended taxpayer money for research into interspecies chimeras. In genetics, a chimera is a natural occurrence where one organism has two or more different sets of DNA.
But an interspecies chimera contains DNA of two or more kinds. This raises concerns over whether pigs or other animals implanted with human cells will develop human brain function.
Juan Carlos Izpisua Belmonte and his team said they are aiming "to test the ability to focus on human cells when creating certain tissues, while avoiding any contribution to the brain, sperm or egg."
Mouse sperm
In 2016, scientists from the Institute of Zoology of the Chinese Academy of Sciences created viable mouse sperm from stem cells. To do this, they extracted stem cells from mice and injected them into testicular cells of newborn mice.
Qi Zhou and Xiao-Yang Zhao, who conducted the experiment, also exposed the stem cells to several chemicals involved in sperm development. Among them were testosterone, a hormone that causes follicle growth, and a hormone that causes growth from the pituitary gland.
After two weeks, the scientists obtained fully functional sperm cells. They implanted this sperm into a living egg and transferred the zygotes to female mice. During the experiment, nine mice were born, some of them continued their own offspring. Although this insemination process has not been as effective as artificial insemination using natural sperm (3% success vs 9%), this study offers great hope for future fertility treatments.
Blood stem cells
Two different teams of scientists have developed an innovative approach to the creation of blood stem cells. One group was from Boston Children's Hospital under the direction of George Daly. They started with human skin cells and "reprogrammed" them to become induced pluripotent stem cells. An iPS cell is an artificially created universal stem cell.
Daly's team then introduced transcription factors into iPS cells, which are genes designed to control other genes. After that, the modified iPS cells were implanted in mice for further development. (If you remember, it made those mice cross-species chimeras.)
After 12 weeks, these scientists have created just a precursor of blood stem cells. But the second team managed to go further.
At Weill Cornell College of Medicine, Shahin Rafiy and his team skipped the creation of the IPS. Instead, they took cells from blood vessels from adult mice and injected them with four transcription factors. They then moved the cells into Petri dishes, equipped to recreate the human blood vessel environment.
These cells are transformed into blood stem cells. The stem cells from this experiment were so powerful that they completely cured a group of mice suffering from low blood cell counts due to radiation therapy.
Apple ears
In 2016, Canadian biophysicist Andrew Pelling and his team at the University of Ottawa successfully grew human tissue using apples. With the help of the method of decellularization, they removed the cells existing in the apple and remained with the cellular "forests". However, it is this cellulose that gives apples their juicy crunch.
Pelling and his team cut an ear-shaped piece of apple and inserted human cells into it. The cells filled in the structure and created the auricle (the outer part of the ear).
Why was this experiment needed? To create cheaper implants. Pelling said his laboratory material is also less fiddling with than conventional biological materials, which are often taken from animals or dead bodies. His method is also not limited to apples. He tries to reproduce his creations on flower petals and other vegetables.
Rabbit penis
In 2008, Dr. Anthony Atala of the Wake Forest Institute for Restorative Medicine forced a group of rabbits to mate. But this was no ordinary group of rabbits. All males had lab-grown penises. Atala has been hatching and developing this idea since 1992.
Of the 12 lab-created penises, all allowed rabbits to mate. Eight rabbits ejaculated successfully and four had offspring.
By 2014, Atala and his team had created six human penises with the hopes of gaining FDA approval for human transplantation. Scientists have rigorously tested the organs grown in the laboratory using a machine that stretches and squeezes them to make sure they can withstand the daily stress.
A group of scientists also tuned machines to pump fluid around the organs and lead to an erection. As of 2017, human transplantation of these organs has not yet received approval, but it is still ahead.
Vaginas
Dr. Anthony Atala and his team have also grown human vaginas in their laboratory. These organs were then implanted in four teenagers in Mexico who, through a rare abnormality, were born without them.
To create these organs, Atala's team took a small sample of each girl's skin. Then they created biodegradable forests and implanted cells grown from tissue samples into them.
The first of these operations took place in 2005. Follow-up of the women revealed no long-term complications associated with the operation. All four women reported normal sexual functioning. However, only two women have uterus. It is unclear if the other two will be able to carry the children.
Brain balls
Sergiu Pasca of Stanford University has been growing a mini-brain for two years. Scientists call it a cerebral organoid. At just 4 millimeters in diameter, this small lump of human brain tissue was grown from stem cells in a laboratory. By taking the right hormones, the scientists were able to force the tissue to grow into a structure that almost completely mimics parts of the brain.
And you know what was the biggest difference between a regular piece and a miniature version?
Lab-grown brains did not have blood vessels or white blood cells and did not follow typical stages of neurological development. Instead, they ceased to mature in the equivalent of the first trimester of human development.
The brain contains non-neural cells called astrocytes that reach full maturity in laboratory organelles. Astrocytes are helper cells that create and reduce connections between neurons as needed. They also create connections with blood vessels to and from the brain and play an important role in the perception of trauma.
Ilya Khel