Engineering intestinal mucosal tissue grafts as a novel treatment for inflammatory bowel disease.

Inflammatory bowel disease is a life-long condition which affects many adults and which can begin in children as young as 5. This disease involves the formation of ulcers and scarring in the bowel which causes pain, bleeding and diarrhoea. Common treatment involves powerful drugs that do not always prove effective and have significant side effects. If patients do not respond to drugs then surgery is often the only option. Surgery involves removing diseased parts of bowel and in severe cases may require a colostomy where the intestines are diverted to the outside of the body and contents draining externally into a stoma bag. Whilst operations can help reduce disease symptoms in the short term, it may result in patients having problems with malnutrition and maintaining hydration. Additionally, surgery is not a cure and half of all patients require further surgery within 10 years of the first procedure.

The quality of life for people with inflammatory bowel disease can be very poor as current treatments are often not completely effective and may only offer temporary respite. Developing new treatments for inflammatory bowel disease is thus urgent and important.

The aim of this project is to utilise stem cells technology with advanced materials and 3D printing to develop replacement bowel tissue in the laboratory which can be safely inserted into the large bowel (colon) as a graft thereby avoiding a stoma and possibly restoring bowel function. Recent research has made it possible to take skin cells and turn them into stem cells which can form any tissue in the body. It follows from this that replacement tissue can be created from a patient's own cells which avoids the risk of organ rejection.

To do this, I need to establish the conditions which make stem cells form the cells which line the colon. Already in proof of concept studies I have successfully grown stem cells in the laboratory to form early colon cells. Incorporating this with cutting-edge 3D printing technology, I will design materials very precisely with surfaces which will further enhance the quality of intestinal cells we can produce. I will therefore aim to establish the optimal conditions to make induced pluripotent stem cells to grow into colon cells.

Having established how to create functional bowel tissue in the laboratory on a small scale, I will manufacture larger sheets of material which would be suitable for inserting into the bowel. Finally, I intend to test the laboratory grown tissue grafts by implanting them into the colon of an animal host. This will allow me to ensure they function as expected, are safe and remain healthy. This would provide proof-of-principle that these could be inserted into the bowel of humans as a potential treatment.

The combination of stem cell research with cutting-edge materials engineering is a novel approach. If successful, it could lead to the development of a novel treatment in inflammatory bowel disease and in other bowel diseases where surgery is necessary. This project will also help us to understand the mechanisms driving bowel development. In particular, I will investigate how the characteristics of material on which cells grow influence their behaviour (which is highly relevant to the development of patient-specific tissue grafts). The tissue would also be valuable as a laboratory model of bowel disease to research disease development and to test other treatments.

Inflammatory bowel disease (IBD) affects up to 600,000 in the UK. It is a relapsing condition and repeated episodes of inflammatory damage culminate in intestinal fibrosis and increased risk of cancer. Effective treatment which promotes healing may alleviate symptoms and prevent long-term sequelae.

Published data show that altering cellular micro environment can accelerate the healing process. Predicated on this principle, the aim of this project is to (i) drive induced pluripotent stem cells (IPSCs) towards intestinal epithelium cultured on a suitable synthetic biomaterial and (ii) use this as an intestinal graft to treat inflammation. This will build on our previously developed methodology for driving human IPSCs to differentiation as colon / hindgut lineages.

To address this aim, I will:

1. Optimise protocols for growth of intestinalised IPSCs. I will assess the contributions of signalling pathways (eg. beta-catenin, FGF-4, EGF, BMP-4) to growth and phenotype of intestinalised IPSCs when cultured on electrospun gelatin scaffolds. I will investigate phenotype in-vitro through protein and RNA profiling and in vivo through growth characteristics following injection into the renal subcapsule of NOD SCID gamma mice.
2. Investigate the potential of novel 3D-printed scaffolds for growth of intestinalised IPSCs. These will be compared with the electropsun scaffolds. The phenotype will be assessed in-vitro and in-vivo as above.
3. Scale up the in-vitro cultures to produce synthetic tissue grafts. The growth and differentiation characteristics of these will be tested by implanting into the colon of NOD SCID gamma mice.

This project will allow us to re-create intestinal mucosal tissue in laboratory conditions. This will potentially give us the means to make IPSCs a useful regenerative medicine therapy for people with IBD and provide better in vitro models of intestine.

Society
Inflammatory bowel disease principally begins between the ages of 20 and 40 and incidence is increasing. It is particularly recognised that inflammatory bowel disease is increasing in incidence in children and one of the fastest growing groups are paediatric cases between 5-10 years. This means that for most patients inflammatory bowel disease has a very long course. Current treatments are able to control symptoms to an extent, but in up to half of patients treatment is not fully effective. Many patients need surgery to remove the parts of bowel and there is currently no satisfactory means of replacing intestinal function. This results in long-term complications which is a significant healthcare burden; it is estimated that inflammatory bowel disease costs the UK health service £1 billion per year. Inflammatory bowel disease is debilitating and patients very often have a poor quality of life and increased sickness absence from employment. This project aims to create the technology required to develop a novel treatment for people with inflammatory bowel disease. Specifically, we will use induced pluripotent stem cells, which can be created from adult cells. We will develop suitable biological materials and culture conditions in which to grow the cells as an intestinal tissue graft and implant the graft into an animal host to demonstrate clinical utility. This would provide another option for managing inflammatory bowel disease and over time this treatment could substantially reduce immediate and long-term healthcare-related costs. Replacement intestinal tissue would improve the ability of people with this disease to lead a healthy life. This would be of great personal benefit to people with inflammatory bowel disease but would also increase their contributions to society in terms of social, economic activity and productivity in employment. This would ultimately reduce the economic costs associated with inflammatory bowel disease.

Economic
Translating the findings into a clinically useful therapy would be enhanced by partnership with the UK biotechnology/pharmaceutical industries and cell and gene therapy catapult. This would generate investment in these industries and revenue from a commercialised therapy. Refining these tissues for use in patients would take at least 5 years. Proving their safety would require a clinical trial study and regulatory approval; it is estimated that it would take 10-15 years for this to be realised.

UK Science
The development of such a novel treatment would increase international recognition of UK-based stem cell and regenerative medicine research which is also likely to increase investment in UK universities and other research institutions. This is likely to be over a longer timeframe, over 10-15 years.

Related Scientific Fields and Medicine
Research in this area may be more generally applied to patients with other chronic conditions which result in organ failure. In particular, the understanding of how engineered materials and stem cells interact to create a safe, functional mature organ could be very generally applied, for instance in people with chronic liver disease, renal failure or where organs are removed because of malignancy. This is important because there are insufficient donor organs to meet the needs of transplant patients. This project could lead to the development of in vivo-like in vitro tissue models. This would be beneficial to understanding disease development and drug delivery. If disease models could be created from induced pluripotent stem cells, it may be possible to perform patient-specific disease modelling which could enhance personalised medicine. This could also help to reduce the use of animals in research. The benefit of enhancing laboratory-based tissue studies could be realised more quickly, as the field and required technology is rapidly developing and less regulatory approval is necessary; this could therefore be achieved within 10 years.