Kyoto: A team of Japanese researchers has worked out a method to produce a large volume of cells from which blood platelets can be derived outside the human body, using artificially created stem cells.
    
Researchers from Kyoto University and the University of Tokyo found that the method using so-called induced pluripotent stem (iPS) cells may prove to be a boon for those who need repeated blood transfusions such as patients with blood cancers as well as aplastic anemia who suffer from declining bone marrow function.
    
Platelets aid clotting and are collected from donated blood, of which supplies tend to run short.
    
The team including Koji Eto, a regenerative medicine Professor at Kyoto University's Center for iPS Cell Research and Application, said it aims to set up a bank to store such base cells that could be used for people requiring repeated blood transfusions.
    
A clinical application of iPS cells is often associated with cancer risks but the method is free of such concerns, according to the team, because platelets do not have nuclei and irradiation is applied before transfusions to kill other cells.
    
A presentation on the method is scheduled for a meeting of the American society of Hematology in the United States on Monday.
    
The team derived blood cells from human iPS cells and introduced two genes into them for culture with protein. They then generated cells that serve as the base for megakaryocytes, which produce platelets.
    
The cells, in crude form, multiplied incessantly. After an agent added beforehand is removed, they grew into megakaryocytes over the period of two to three weeks and turned into platelets.
    
When a dose was given to a mouse, a clot was formed in a damaged blood vessel and bleeding was arrested, according to the team.
    
While platelets need to be stored at room temperature and only have a life of several days, crude megakaryocytes can be preserved frozen.
    
In a human body, a megakaryocyte produces around 2,000 platelets. Under the team's method, only up to 40 platelets are produced, suggesting room exists for arriving at optimal conditions for culture.
   
Eto said, ''We would like to develop a method for more efficient production and start clinical research in three to four years.''
    
The team also succeeded in generating similar results using embryonic stem cells. IPS cells are produced by introducing genes into skin cells, for instance. Both cells from human embryos and iPS cells have the potential of turning themselves into various human cells and organs.

Agencies