Collagenases in pancreatic islet isolation

Collagenases, essential elements in experimental and clinical islet isolation, have been the subject of numerous investigations over the last three decades in order to standardize and optimize the enzyme blends for pancreatic tissue dissociation. Through these studies, the contribution of separate components of traditional crude clostridial collagenase preparations, including collagenase G (ColG), collagenase H (ColH), neutral proteases, and clostripain, has been largely unraveled. We can, therefore, now redefine the enzyme parameters necessary for optimum digestion and a high yield and quality of islets, coupled with significant advances in the manufacture process. In this chapter, the authors describe the structure of clostridial digestive enzymes with emphasis on collagenase molecular forms, review the progress on activity assays of digestion enzymes, expound on the current understanding of enzyme contribution in relation to extracellular matrix composition in the peri-insular region as well as concerns regarding lot-to-lot variability and enzyme safety, discuss advances in recombinant collagenases and animal-free preparations, and outline the current efforts for a tailored donor-specific approach.