3 research outputs found
The influence of porcine pancreas digestion parameters and islet histomorphology on islet isolation outcome
Transplantation of the pig islets of Langerhans is considered as the future treatment for patients
suffering from type I diabetes mellitus. Despite the adaptation of modified Ricordi method and highly
purified collagenase, the results of pancreas digestions are precarious. Selection of proper donor and
optimal digestion procedure are fundamental. The aim of this study was to assess the impact of
pancreas procuring parameters on pig islets yield. The pancreata were harvested from 69 market sows
weighting over 150 kg. After intraductal injection of cold collagenase solution pancreata were transported
in UW solution or under conditions of two layer method (TLM). In laboratory pancreata were
digested at 37℃ according to Ricordi isolation method or stationary in the bottle. The particular
parameters of isolation procedure were considered as substantial. Pig weight, volume of infused
collagenase solution, TLM application and pancreas dividing before digestion positively affected islet
yield. Additionally, the influence of pancreatic islet tissue histomorphology on isolation outcome was
studied. Proper donor selection as well as adequate digestion parameters could improve pig islet
recovery during islet isolation
Improvement of islet function in a bioartificial pancreas by enhanced oxygen supply and growth hormone releasing hormone agonist
Islet transplantation is a feasible therapeutic alternative for metabolically labile patients with type 1 diabetes. The primary therapeutic target is stable glycemic control and prevention of complications associated with diabetes by reconstitution of endogenous insulin secretion. However, critical shortage of donor organs, gradual loss in graft function over time, and chronic need for immunosuppression limit the indication for islet transplantation to a small group of patients. Here we present a promising approach to address these limitations by utilization of a macrochamber specially engineered for islet transplantation. The s.c. implantable device allows for controlled and adequate oxygen supply and provides immunological protection of donor islets against the host immune system. The minimally invasive implantable chamber normalized blood glucose in streptozotocin-induced diabetic rodents for up to 3 mo. Sufficient graft function depended on oxygen supply. Pretreatment with the growth hormone-releasing hormone (GHRH) agonist, JI-36, significantly enhanced graft function by improving glucose tolerance and increasing β-cell insulin reserve in rats thereby allowing for a reduction of the islet mass required for metabolic control. As a result of hypervascularization of the tissue surrounding the device, no relevant delay in insulin response to glucose changes has been observed. Consequently, this system opens up a fundamental strategy for therapy of diabetes and may provide a promising avenue for future approaches to xenotransplantation