|Regenerative medicine is the term used to refer to methods that aim to replace or regenerate cells, tissues or organs in order to restore or establish normal function. This can include a range of techniques including cell therapies, tissue engineering and gene therapy.
Stem cells are cells that have the ability to continuously divide to generate exact copies of themselves in a process called self-renewal and the ability to change into specialised cells in a process called differentiation.Differentiation is the process by which an unspecialised cell acquires the features of a specialised cell such as a heart, kidney, liver, or muscle cell. This process is controlled by the interaction of a cell’s genes with the physical and chemical conditions outside the cell, usually through signalling pathways involving proteins embedded in the cell Surface.
There are several different types of stem cells which are characterised by their origin and potential to differentiate.
Embryonic stem cells are undifferentiated cells derived from a pre-implantation embryo which have the potential to differentiate into many different types of cells, i.e. they are pluripotent.
Tissue stem cells (sometimes referred to as adult or somatic stem cells) can give rise to at least one specialised (differentiated) cell-type.
- Unipotent stem cells can only make one type of specialised cell
- Multipotent stem cells have the ability to develop into a limited number of specialised cell types
- Pluripotent stem cells are cells that are capable of differentiating into a wide range of tissues. While tissue stem cells are not naturally pluripotent, it is now possible to induce this feature by artificially activating specific genes. These are called induced pluripotent stem cells (iPS).
A stem cell therapy is a treatment that uses stem cells, or cells that come from stem cells, to replace or to repair a patient´s cells or tissues that are damaged. The stem cells might be put into the blood, or transplanted into the damaged tissue directly, or even recruited from the patient´s own tissues for self-repair.
Autologous stem cells are collected from the same animal in which they are used as treatment.
Allogeneic stem cells are those where the donor and recipient are different individuals from the same species.
There is currently a great deal of research taking place into stem cell therapies in both human and veterinary medicine.