We produce neurons by direct reprogramming of somatic cells, for example the skin fibroblasts obtained from skin punch biopsies of 58 years-old donors. This means that in the future, we could produce autologous neurons from any human donor.
Our technology has three advantages:
- We have developed a formulation of cryoprotectants to preserve skin punch biopsies 3mm in diameter into dry ice for long distance shipping. Outpatient biopsies are convenient for donors with reduced mobility. Following this procedure, frozen dermal tissues successfully produced fibroblasts that were reprogrammed into neurons.
- Our reprogramming procedure is direct from somatic cells, without pluripotent cell intermediates. This removes the risks of teratoma formation in implanted neurons derived from pluripotent stem cells.
- Our procedures do not involve expression vectors or transgenes. In absence of exogenous sequences and without any possibility of insertional mutagenesis, the risk of tumor formation upon reimplantation of autologous neurons should be strongly reduced compared to other methods.
In transplantation trials in immunodeficient animals like SCID mice, our neurons should produce no teratomas. This makes our induced neurons interesting candidates for autologous implants in patients with spinal cord injuries. An example of neural reprogramming is shown below, starting with skin fibroblasts (left) obtained from a skin punch biopsy, the cells were slowly reprogrammed into neurons (right). We have also developed biodegradable support gels for these neurons, so that they would be easy to insert into the spinal cord of paralyzed patients. Finally, neurons will derive from the somatic cells of each patient, to make personalized, autologous neural implants that do not require immunosuppression.
