Researchers at London's Great Ormond Street Hospital aim to grow a human ear via stem cells taken from a patient's fat tissue. Relatively little attention has been given to the reconstruction of damaged cartilage around the cranial area, however the new method is hoped to modernize this area of reconstructive surgery.
Currently to repair damaged or non-existent cartilage in the ear, an operation is usually carried out when the patient is a child. Cartilage is extracted from the patient's ribs and painstakingly crafted into the form of an ear, before being grafted back onto the individual.
Whilst this method of reconstruction achieves good results, it also has some unpleasant side effects. The patient is left with a permanent defect around the area from where the cells were harvested, as the cartilage between the ribs does not regenerate. Since any operation to replace the cartilage in the ear is for cosmetic purposes only, curing one defect by creating another (albeit in a less obvious place) is not an optimal solution.
The cartilage cells used in the new technique are engineered from mesenchymal stem cells, extracted from the child's abdominal adipose tissue (fat). The benefit of this new system is that unlike the cartilage in the ribs, the adipose tissue regenerates, therefore leaving no long-term defect to the host. There is also the potential to begin reconstructive treatment with stem cells derived from adipose tissue earlier than previously possible, as it takes time for the ribs to grow enough cartilage to undergo the procedure.
Dr. Patrizia Ferretti, a researcher working on the project, told Gizmag, “One of the main benefits in using the patient’s own stem cells is that there is no need for immune suppression which would not be desirable for a sick child, and would reduce the number of severe procedures a child needs to undergo."
To create the form of the ear, a porous polymer nano-scaffold is placed in with the stem cells. The cells are then chemically induced to become chondrocytes (cartilage cells) while growing into the holes in the scaffold to create the shape of the ear.
"Cellularized scaffolds integrate much better than fully synthetic implants, which are more prone to extrusion and infection," Dr. Ferretti explained.
The new, and potentially more advantageous technique would replace the current set of procedures in the treatment of defects in cartilage in children such as microtia, a condition which prevents the ear from forming correctly.
Dr. Ferretti continued that “While we are developing this approach with children with ear defects in mind, it could ultimately be utilized in other types of reconstructive surgery both in children and adults." Such reconstructive technology has the potential to be invaluable in improving the quality of life of those who have been involved in a disfiguring accident or even those injured in the line of service.