Banks of off-the-shelf body parts could be created for transplants: researchers
Off-the-shelf body parts could soon be available for surgeons to use to repair injuries or patch-up worn out organs, researchers claim.
By Rebecca Smith, Medical Editor
Published: 7:50AM BST 14 Jul 2010
Scientists are perfecting ways of creating bare ‘scaffold’ building blocks of body parts which can then be used as a frame for a patient’s own cells to grow around.
The technique involves taking a piece of dead donor or animal body part and removing all the soft tissue so just the bare structure is left. Stem cells from the patient can then be placed on the frame and will regrow into a new body part for them.
The technique has already been successful in creating a new section of windpipe for patients who have suffered injury or disease and it is hoped it can be used for a wider set of organs.
Experts said the scaffold for the most commonly used parts could be created in advance and stored ready for use when needed.
Prof John Fisher from The University of Leeds spoke at a stem cell conference of the potential to create banks of scaffolds of all kinds of body tissue so surgeons can then finish them off with a covering of tissue grown from the patient before they are implanted.
He told the UK National Stem Cell Network Annual Science Meeting in Nottingham of work he and his colleague Prof Eileen Ingham have been working on to create the scaffolds from dead donors or animals.
So far, patches to cover a hole or weakening in a blood vessel, knee cartilage and tendons have been created.
The advantage of the method is that the patient will not reject the transplanted tissue as foreign because the scaffold is stripped of all material that can trigger rejection and the soft tissue is grown from their own stem cells.
It means patients can avoid powerful immunosurpressant drugs which shorten life expectancy and can increase the risk of cancer.
Scaffolds derived from human donor tissue are being developed by the NHS Blood & Transplant Tissue Services, while scaffolds developed from animal tissues are being developed and commercialised by Tissue Regenix Group PLC.
Prof Fisher said: “If you take a natural tissue and strip off all of the donor’s cells you’re left with a biological scaffold made mostly of a protein called collagen, which is compatible with the patient receiving the scaffold.
“That scaffold is good from an engineering perspective because it’s strong, flexible and retains the properties of the natural tissue. It also has the appropriate shape and size, and from a biological perspective is good because a patient’s cells can bind to it and repopulate it easily.”
The transplants are also expected to last longer than those in use currently because the technique overcomes the problem of rejection.
Prof Fisher said chemically treated and strengthened prosthetic heart valves from pigs, for example, have been in used in human transplants for more than a decade, but the chemical process which stops them from being rejected by the patient’s immune system also leaves them lifeless so they degrade over time and need to be replaced.
He added:”These new biological scaffolds will provide off-the-shelf tissues for surgeons for repairing blood vessels after surgery for blocked arteries, for repairing knee cartilage after sporting injuries and cartilage tears, for repairing torn ligaments or tendons and for heart valve repair or replacement.”
Other more complex structures like a voicebox could be replaced in the same way but the demand for such specialist transplants is more limited and so it is unlikely bio-tech companies would make scaffolds for these in advance and store them.