Pancreatic Islets: Methods for Isolation and Purification of Juvenile and Adult Pig Islets

Abstract

The current situation of organ transplantation is mainly determined by the disbalance between the number of available organs and the number of patients on the waiting list. This obvious dilemma might be solved by the transplantation of porcine organs into human patients. The metabolic similarities which exist between both species made pancreatic islets of Langerhans to that donor tissue which will be most likely transplanted in human recipients. Nevertheless, the successful isolation of significant yields of viable porcine islets is extremely difficult and requires extensive experiences in the field. This review is focussing on the technical challenges, pitfalls and particularities that are associated with the isolation of islets from juvenile and adult pigs considering donor variables that can affect porcine islet isolation outcome.

Heterogenous expression of endocrine and progenitor cells within the neonatal porcine pancreatic lobes–Implications for neonatal porcine islet xenotransplantation

“…36 Some of the differences amongst groups that are attributed to porcine donor characteristics include; strain, 1,28-32 age, [29][30][31][32]42,43 sex, 25,42 anatomical variations, 25,28,29,30,32 housing, and diet. 39,42 In addition, in vitro procedures also differ with respect to; pancreas procurement, islet recovery, and culture conditions. [9][10][11][12]42,44 In comparison, lessons learned from human islet isolation and transplantation have resulted in the development of an islet donor scoring system.…”

“…39,42 In addition, in vitro procedures also differ with respect to; pancreas procurement, islet recovery, and culture conditions. [9][10][11][12]42,44 In comparison, lessons learned from human islet isolation and transplantation have resulted in the development of an islet donor scoring system. [45][46][47][48] For example, The North American Islet Donor Score (NAIDS) is a predictor of islet isolation success and used for human pancreas donor selection for both clinical and research islet isolation.…”

“…There are obvious different experimental outcomes attributed to porcine donor variables, and in vitro experimental conditions. 36,42,43,50 We are not the first to cite anatomical variations in the neonatal porcine pancreas, but we are the first to demonstrate that these anatomical variations affect in vitro and in vivo function, such that, anatomical variability can hinder comparisons and reproducibility. For example, we report that the DL and CL (each 25% of the pancreatic weight) contain PDGs, and NPI from these lobes exhibited the greatest fold change in the insulin/DNA ratio.…”

Comparison of Islet Characterization from Use of Standard Crude Collagenase to GMP-Grade Collagenase Enzyme Blends in Preweaned Porcine Islet Isolations

“…In this case, integrity tends to be the limiting factor. Although present in human, rat, and even adult pig isolations, analysis of optimization of enzyme blend is lacking in preweaned-aged porcine isolations 29,30,31 . The results presented reveal that consistent GMP-grade enzyme blends are capable of being as effective as crude enzymes in producing optimal PPIs.…”

Comparison of Tissue Loading Before and After the Creation of a Continuous Density Gradient in Porcine Islet Purification

“…However, the successful isolation of significant yields of viable porcine islets is extremely difficult and requires extensive experience in the field. Several groups have described the technical pitfalls associated with the isolation of islets from juvenile and adult pigs [25][26][27] . As we used porcine pancreata in this study, islet purification using large plastic bottles may be useful for not only clinical islet isolation but also islet xenotransplantation.…”