Thanks for your inputs and throwing more light on this topic. I further searched and found that in India, Hyderabad, they are doing islet transplant using theracite implantation where the islets are sealed in a small cell and introduced in the body of the patient. due to this, the body will not reject the islets, and the patient wont need immuno suppressants. Please see the extract below from the news site:
"He further said, “Pancreatic islets transplantation can let diabetics live without using insulin injections for about 3-5 years depending on the patient. However, the main problem with this process was immuno-rejection, which can be solved using theracite implantation.”
According to Dr Prasad, theracite implantation means islets are sealed in a small cell and introduced in the body of the patient. As a result of this, the body will not reject the islets. “So, islets can be extracted from donors or patients (with their consent), isolated, cultured and multiplied, in order to use them on diabetic patients, solving their problem on a long-term basis,” added Dr Prasad.