A new method to value efficiency of enzyme blends for pancreatic tissue digestion.

Abstract

Islet transplantation, since the 90’s, has been resulting to be one of the best successful example of human cell therapy. Nevertheless, islet isolation procedure is not completely standardized; in fact, more than fifty percent of islets procedures don’t arrive to their transplantation. This is due both to the variability of donor’s pancreas and to an unpredictable enzymatic blend efficiency. Enzymes used in pancreas digestion are extracted from Clostridium histolyticum bacteria and digest several substrates. In particular they have strong collagenolytic activity compared to vertebrate collagenases. However, several impediments persist in human islet isolation success probably due to the variability in composition and concentration of collagenases used during the digestion phase‏. In islets isolation’s process neutral protease is also used and plays an important role. However, it should be considered as double-edged sword: it contributes to accelerate the tissue dissociation but, sometimes, its action could result decreased in islet yield, through their fragmentation, breakdown, inactivation‏. Proteases’ activities cannot be preciously adjusted in a narrow range since it doesn’t exist any approach showing the best possible dosage and composition of enzymes that can be used in a successful process of human islets pancreas extraction. At the moment, the available data on commercial enzymatic activity are not sufficient to predict their efficiency in the process of pancreas digestion and consequently it is very difficult to select which enzyme batches can be successfully used. For these reasons we apply to generate an innovative evaluation assay to select enzymes useful in islet pancreas isolation procedure.