Richard Gray June 11, 2012
Scientists have paved the way for human bones to be replaced with new ones grown outside the body. Photo: iStockphoto
SCIENTISTS have grown human bone from stem cells in a laboratory, paving the way for patients to have broken bones repaired - or even replaced with new ones grown outside the body from their own cells.
Researchers started with stem cells taken from fat tissue. It took about a month to grow them into sections of fully formed living bone up to several centimetres long.
The first trial in patients is on course for later this year, by an Israeli biotechnology company that has been working with academics on the technology.
Professor Avinoam Kadouri, head of the scientific advisory board for Bonus BioGroup, said: ''We use three-dimensional structures to fabricate the bone in the right shape and geometry. We can grow these bones outside the body and then transplant them to the patient.
''By scanning the damaged bone area, the implant should fit perfectly and merge with the surrounding tissue. There are no rejection problems as the cells come from the patient.''
The technology, developed with researchers at the Technion Institute of Research in Israel, uses three-dimensional scans of damaged bone to build a gel-like scaffold that matches the shape.
Stem cells, known as mesenchymal stem cells, that have the capacity to develop into many other types of body cell, are taken from a patient by liposuction and are then grown into living bone inside a ''bioreactor'' - a machine that provides the conditions to encourage the cells to develop into bone.
Animals have already successfully received bone transplants, but in the latest study, the scientists were able to insert almost 2.5 centimetres of laboratory-grown human bone into a rat's leg bone, where it successfully merged with the remaining animal bone.
The technique could ultimately allow doctors to replace shattered bones, fill in defects where bone is missing - such as cleft palate - and carry out other reconstructive surgery.
Professor Kadouri said work is being done to grow the soft cartilage at the ends of bones, which is needed if bones are to be produced in a laboratory.
Bone grafts involve transplanting bits of bone from elsewhere in the patient's body and require the patient to have two traumatic operations. Bone is also obtained from donations, but can be rejected by the body. The new technique reduces the chance of rejection.
Dr Shai Meretzki, chief executive of Bonus BioGroup, said they hoped to develop the technology to replace damaged joints such as hips.
Several teams around the world are regrowing bone using stem cells, but most use a different kind of cell and inject them into the patient.
Professor Alicia El Haj, head of the regenerative medicine group at Keele University, has treated 450 patients using cartilage cells and her team has started trials using cells from bone marrow.
She said: ''There are a lot of people coming up with cells that can be used to repair bone, but there are not many progressing to produce tissues that can be grown outside of the body and used clinically. It is an important step.''