Growing new organs

The first man to ever grow an organ was surgeon Paolo Macchiarini from the Karolinska Institutet. The organ was a trachea, one of the simplest human organs which essentially is a tube connecting the pharynx and larynx to the lungs, allowing the air to pass. This breakthrough was achieved in 2008 and the organ was transplanted to a woman who had her own trachea collapsed due to tuberculosis. Since then, Macchiarini and his team have done a lot of progress and have also grown in the lab other simple organs like an esophagus and a diaphragm.

In his method, Macchiarini first extracts autologous (taken from the patient himself) mesenchymal stem cells . The stem cells are then mass-cultured and placed in a graft that has a structure similar to the organ they want to create. The cells then gradually absorb the graft and the new organ is created and ready for transplantation. According to the published literature, when the right cells are combined with the correct biomaterials the derived organ is virtually indistinguishable from an original organ. 

In September 2012, researchers from the Johns Hopkins University Hospital reported that they successfully transplanted, for the first time, a new ear on a woman that had lost her own as a result of a rare aggressive type of skin cancer.

The researchers took cartilage from various parts of her body and implanted them on her forearm allowing these parts to grow. Later, once the new ear had fully matured it was removed and transplanted to the woman’s head.

In March 2013, researchers from the King's College London announced that they were able to grow new teeth, very similar to the ones human have, using a combination of cells taken from adult human gingival tissue (gum) and mouse embryonic stem cells. The combined cells were then transplanted into mouse renal capsules (a layer surrounding kidneys), where they gradually developed into new teeth. The new teeth had both dentin and enamel along with the capacity to form new roots.

For now these are all the organs scientists have managed to succesfully created. However it should be mentioned that they have succesfully managed to create many different tissues comprising various organs including:

• Hyaline cartilage (knee cartilage)
• Heart muscle tissue
• Skin
• Brain and spinal neurons
• Eye lenses

Who knows, maybe within the next 20-30 years growing a heart or a limb may be a routine procedure..

• http://www.stemcellsfreak.com/2013/02/growing-organs-from-stem-cells.html
• http://www.stemcellsfreak.com/2013/03/tooth-replacement-stem-cells.html