A new way to try and carry out bone marrow transplants without using toxic chemotherapy has been investigated.

A technique has been developed by researchers at the Stanford University School of Medicine who have been looking for a way to wipe out a patient's own bone marrow, creating room for donated cells, without the traditional option of chemotherapy or radiation.

Side effects can include damage to the liver, reproductive organs and brain and potential seizures.

The scientists, whose findings are published in the Science Translational Medicine journal, worked with immune-deficient mice.

They started by attaching an antibody to a cell surface protein, called c-kit, which is a primary marker of blood stem cells. This led to a drop in blood stem cells.

They then looked to bolster its effectiveness by combining it with antibodies or biologic agents to block another cell surface protein called CD47. The aim was to try and "eat" target cells covered with c-kit antibody.

This cleared the way for transplanted blood stem cells from a donor to appear in the bone marrow and trigger a new blood and immune system.

Bone marrow transplants currently involve a mix of cells, including blood stem cells plus various immune cells from the donor, which can attack the tissue of the transplant patient.

The scientists feel they may have been able to purify the donor tissue so that it contained only blood stem cells and not the other immune cells that attack and damage the tissue.

Stanford researcher Judith Shizuru said they had used "safer techniques to seed the new blood-generating cells" adding: "If it works in humans like it did in mice, we would expect that the risk of death from blood stem cell transplant would drop from 20% to effectively zero."

Research co-author Irving Weissman said: "If and when this is accomplished, it will be a whole new era in disease treatment and regenerative medicine."

A potential bonus is that it opens up the prospect of a one-time application of blood stem cell transplantation being available to help cure any disease caused by the patient's own blood and immune cells.

They also suggested that safely replacing a patient's blood and immune cells would get rid of the cells that attack the tissues and produce diseases like rheumatoid arthritis and Type 1 diabetes.