Stem cells have unique characteristics lending them the potential to be utilised in many ways to benefit and increase understanding of human health. Discoveries in this area will deliver knowledge of developmental and ageing processes and provide the foundation for regenerative medicine therapies for a range of diseases including Parkinson’s disease, cardiovascular disease, wound and musculoskeletal repair, eye disorders and deafness.
What are stem cells?
Stem cells are unspecialised cells capable of renewing themselves through cell division and have the potential to develop into many different cell types playing a central role in generation and regeneration of the body. In many tissues stem cells serve as an internal repair system, dividing to replenish other cells lost through wear and tear or injury. When a stem cell divides, each new cell may either remain a stem cell or, under certain physiologic or experimental conditions, become another type of cell with a more specialized function, such as a bone or muscle cell.
Stem cells are vital for the development and growth of organisms. In the 3- to 5 day-old embryo, called a blastocyst, embryonic stem cells give rise to the entire body of the organism, including all of the specialized cell types and organs.
Three types of stem cell are mainly utilised in research:
- Embryonic stem cells (ES cells) are obtained from the blastocyst. ES cells are pluripotent, which means they can be induced to differentiate into any of the more than 220 cell types in the adult body
- Adult (somatic) stem cells are unspecialised cells found throughout the body after development. Adult stem cells are multipotent, which means that they typically only give rise to the cells of the tissue in which they are found
- Induced pluripotent stem cells (iPSCs) are a type of pluripotent stem cell that can be generated directly from adult cells bypassing the need for the use of embryos. iPSCs have great therapeutic potential as they can be made in a patient-matched manner, meaning individuals could have their own pluripotent stem cell line
The benefits of stem cell research
Our bodies use somatic stem cells to replace damaged or worn cells. However, where damage is extensive, this repair mechanism can fail. Also, not all of the tissues in our body, for example brain tissue, can repair themselves efficiently, and many degenerative diseases are not yet treatable. While transplantation of some organs is an option, this relies on the availability of transplant organs and organs being a match for the recipient. Stem cell research has the potential to fill this gap in human medical therapies.
Stem cells have many different uses in the laboratory. This is because they can self-renew indefinitely, keeping their potential to develop into specialised cell types. This means that they could provide an unlimited source of new human tissue from a small starting number of cells. One goal is to use stem cells grown in the laboratory to generate cells or organs which can be transplanted into patients in order to repair or replace damaged tissue. However, much is yet to be learned regarding the growth and behaviour of stem cells and how they are turned into specialised cells. Another important application is the use of stem cells to produce models of human diseases. These models could be used to further understand why some diseases occur, to provide sources of cells for identifying new treatments and drugs, and for testing drugs for effectiveness and safety.
How is BBSRC involved?
BBSRC supports research that advances understanding of the biology of stem cells, developing knowledge of their role in health across the life-course and their utility as powerful tools with diverse applications, investing £9.3M in this area in 2014 . BBSRC aims to develop basic understanding of stem cell biology that will enable the development of new regenerative biology technologies to improve the quality of life for the ageing population.
BBSRC’s Strategic Plan recognises that multidisciplinary research combining knowledge in biology, engineering and materials chemistry is needed for the development of new regenerative medicine and tissue engineering applications. In 2012, BBSRC, along with EPSRC and MRC, invested £25M into the UK Regenerative Medicine Platform (UKRMP) funding five hubs to address the technical and scientific challenges associated with translating scientific discoveries towards clinical impact.
There is a huge unmet need for new ways to make bone
Every year there are around 60,000 hip, 50,000 forearm and 40,000 vertebral fractures in the UK. At the Bone and Joint Research Group at the University of Southampton, Professor Richard Oreffo and team have made pioneering advances in the field of bone and tissue regeneration. Last year, a 3D printed hip joint made with a patient’s own stem cells was implanted using this technology.
“It should be simple – we know the cell that makes bone (called an osteoblast), but bone is a complex tissue requiring a blood supply and has unique mechanical properties. In addition, the bone stem cell is also extremely rare to isolate,” Professor Richard Oreffo, University of Southampton.
Stem cells are basic tissue building blocks, with a unique ability to become different types of cells. Professor Oreffo and team harness bone stem cells from bone marrow, and differentiate them to become bone, cartilage or connective tissue. This is then combined with a synthetic, 3D printed scaffold to which the cells coat.
The beauty of the team’s approach is that it can be custom designed for the patient. There is a place for synthetic implants, but by repairing body with the patient’s own tissue, there is less chance of rejection.
With an increasingly ageing population, there are already a number of clinical applications seeing bone marrow cells being applied by orthopaedic surgeons. In 2014, two operations in Southampton were completed using Oreffo’s 3D printed hips, and within 5-7 years this could be a simple procedure for patients in the NHS.