New engineered bone marrow may make transplants safer

A team of US scientists led by an Indian origin researcher has developed biometric bone tissues that could provide new bone marrow for patients needing transplants as well as make the procedure much safer.

Before a transplant, a patient is first given doses of radiation, sometimes in combination with drugs, to kill off any existing stem cells in the patient's bone marrow.

This pre-treatment is meant to improve the success of the transplant by clearing up space in the marrow, allowing donor cells to survive and grow without competition from the patient's own cells.

But this treatment often comes with harmful side effects such as nausea, fatigue, loss of fertility and others. The new bone-like implant gives donor cells their own space to live and grow without competition, eliminating the need to wipe out the host's pre-existing cells.

"We've made an accessory bone that can separately accommodate donor cells. This way, we can keep the host cells and bypass irradiation," said Shyni Varghese, Professor at the University of California San Diego.

The implants, detailed in the journal PNAS, mimic the structure of long bones in the body, consisting of an outer bone compartment and an inner marrow compartment and are made of a porous hydrogel matrix.

When implanted under the skin of mice, the structures, then matured into bone tissues that have a working blood vessel network and a bone marrow inside that supplies new blood cells.

After four weeks, the implanted marrow contained a mix of host and donor blood cells. They also found this mix circulating in the bloodstream of mice even after 24 weeks.

However, these implants would be limited to patients with non-malignant bone marrow diseases, where there aren't any cancerous cells that need to be eliminated, the researchers said.