When a patient has a Heart Attack a portion of the heart muscle is deprived of blood and becomes damaged, sometimes leading to the heart being unable to pump enough blood. Studies have found that delivering proteins called growth factors or stem cells to the heart can help to regenerate the damaged tissue. However, often surgery to access the heart is very invasive and injected growth factors or cells are washed or pumped out due to the constant motion of the heart and therefore produce only limited therapeutic effects. The aim of this project is to investigate the potential of incorporating a growth factor into small particles which will release it very slowly. These particles will then be added to a viscous gel and combined with stem cells. This formulation can then potentially be injected into the heart tissue. The idea is that the viscous gel will stay in the heart tissue and let the growth factors be released over a long space of time and help the cells to stay in one place. This could facilitate greater therapeutic effects. The gel is also concieved as being injectable from a special catheter which would avoid having to undergo a full surgery. The final gel formulation will be tested to see what effect it has on heart cells grown in an incubator outside the body, to see if it can improve cell survival in conditions which mimic those found during a heart attack in the human body.