Synthetic organs eliminate long waiting periods and the need for costly immunosuppressive drugs.
At Karolinska University Hospital in Huddinge, Stockholm, Sweden, a 36-year-old man who suffered from late-stage tracheal cancer was supplied with a new trachea that was grown in the laboratory, seeded by the man’s own stem cells. The procedure was performed by professor Paolo Macchiarini of Karolinska University Hospital and Karolinska Institutet, along with colleagues including professor Alexander Seifalian from University College in London, England.
In spite of maximum treatment with radiation therapy, the man had a tumour that had grown to about six centimeters long and was reaching to the main bronchus. It was continuing to grow and was almost completely obscuring the trachea. Since a suitable donor windpipe was unavailable, the transplantation of the synthetic tissue-engineered trachea was performed as the last possible option for the patient.
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Over 100,000 Americans are now actively waiting for an organ transplant. At the same time, the average yearly expense of immunosuppressive drugs – administered following a transplant to prevent the body from rejecting the new organ – is over $11,000, and in some cases can reach as high as $25,000, according to the American Society of Transplant Surgeons.
These sobering statistics are driving a campaign within the biomedical research community for innovation. Among the most promising avenues is the creation of techniques for growing a replacement organ from a patient’s own stem cells. By doing this, we get rid of the long waiting period that might be needed for the patient to receive an appropriate organ, and eliminate the requirement for immunosuppressive drugs after the procedure.
The operation in Sweden is the first time a synthetic organ has been successfully transplanted into a patient. The control technology that made the surgery possible was a shoebox-sized apparatus known as a bioreactor, created by Harvard Bioscience, in which the new trachea was grown. The bioreactor was loaded with a nanocomposite “scaffold,” which was conceived and constructed by professor Seifalian, and was manufactured out of a porous plastic polymer material conforming to the shape of the man’s original trachea. Over a period of approximately two days, the scaffold was rotated within the bioreactor while its surface was soaked with stem cells obtained from a bone marrow biopsy from the patient’s hip.
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Over that interval of two days, the patient’s stem cells settled into the pores within the scaffold, and began to grow into each other, slowly transforming from individual cells into genuine tissue. A few days after the implantation of the new trachea, the man’s blood vessels actually started to grow into it, transforming the new organ into a part of his own body. Because the man’s own stem cells were employed in the procedure, his body accepted the transplant without using any immunosuppressive drugs. The patient was later discharged from the hospital and is doing well.
What does the future have in store for this type of bioreactor technology? For the near future, the scaffold technique for creating synthetic body parts will be confined to tubular organs such as trachea and blood vessels, instead of more complicated organs such as kidneys and livers. However, alternate types of organs may become a practical option later on.
This procedure could mean the start of a new era in the treatment of thousands of patients whose lives and health will be significantly improved.
Photo courtesy of Reuters.
