Bioartificial endocrine pancreas (Bio-AEP) for treatment of diabetes: Effect of implantation of Bio-AEP on the pancreas

Recently, we described a diffusion chamber for a bioartificial endocrine pa ncreas (Bio-AEP). Pancreatic islet cells in the Bio-AEP device were isolate d from the immune system of the host by an artificial barrier, while nutrie nts, electrolytes, oxygen, and bioactive secretory products were exchanged across this barrier. This experiment was designed to evaluate whether the d iffusion chamber could be useful as a Bio-AEP in the treatment of diabetes. Six streptozotocin (STZ)-induced diabetic rats each received a diffusion c hamber containing 8 x 10(6) MIN6 cells as a xenograft Bio-AEP. In the STZ d iabetic rats with Bio-AEPs, a return to normoglycemia was observed up to 30 weeks after implantation, without the use of any immunosuppressant, A grad ual increase in the body weight of the rats was also observed. In three STZ diabetic rats, diffusion chambers without MIN6 cells were implanted as a s ham operation. The fasting blood glucose levels in these three rats remaine d higher than 600 mg/dl, after implantation, and they lost weight, Thirty-f ive weeks after implantation, the pancreata were removed from the rats that underwent xenoimplantation, those that had the sham operation, and the nor mal control rats. In the sham-operated animals, the exocrine tissues of the pancreata were vacuolated and pancreatic B cells were not seen in the isle ts. In contrast, in the pancreata from the xenoimplantation, the exocrine t issues were normal, and a few pancreatic B cells were seen in the islets. T hese results indicated that xenoimplantation using the Bio-AEP might retard the progress of diabetes.