Xenotransplantation, the process of transplanting organs from one species into another, could soon be reality, easing the current shortage of organs for transplantation.

In 2005 Dr. Warrens, from Imperial College London and Hammersmith Hospital, says: "Although the idea of xenotransplantation is far from new, it is only in recent years that many of the potential immunological problems, such as transplant rejection, have been solved, meaning the process of transplanting organs from one species into another, could soon be a reality."

With the increasing shortage of donors for organ transplants, the use of animal organs may be the only hope for many suffering from problems such as heart failure.

Despite the progress made in this field there are still a number of problems associated with transplanting animal organs into humans. The dangers of animal viruses crossing over and infecting humans are still a cause for concern, as researchers have been unable to create an animal model to test the likelihood and extent of any cross over.

In addition, unknown animal pathogens could prove a potential problem. While scientists can create treatment and transplant rejection prevention strategies for known human pathogens, they are unable to do so for animal pathogens, whose effects on humans may not be fully known.

Dr Warrens adds: "Despite the risks, xenotransplantation may be the best hope we have for dealing with the current transplant shortage.

Source: Imperial College London

Scientists had predicted since the 1970s that gum tissue could contain its own specific stem cells, but until recently, limited technology had failed to show such cells.

In July 2007 US scientists at the National Institute of Dental and Craniofacial Research (NIDCR), isolated human postnatal stem cells directly from the periodontal ligament, the fibrous, net-like tendon that holds our teeth in their sockets. These stem cells turned out to actually form periodontal ligament and cementum when transplanted into mice. The cells even produced fibrous structures similar to the so called Sharpey's fibers, which insert into both cementum and bone to hold teeth in place.

Read more: Growing New Gums With Stem Cells

There are still several issues when it comes to implanting stem cells in human livers, and scientists say that current problems have been related to immunological reactions against the cells as well as difficulty with how to introduce the stem cells into the liver. However now a novel protein marker has been found that identifies rare adult liver stem cells, whose ability to regenerate injured liver tissue has the potential for cell-replacement therapy.

In the United States, Dr. Fausto and his team of research scientists are trying to identify stem cells in human livers that could be used to help people with liver failure. They are hoping to find a cell that is a stem cell for the liver, and to inject those cells and repopulate livers that have been injured. "The idea is if you could have cells that could be introduced into the patient, it could either be a permanent solution to help the liver regenerate itself or at least serve as a bridge until transplantation can be done" says Dr. Fausto.

Read more: Liver Stem Cell Treatments