BACKGROUND: Biologic characteristics of enzyme products used for islet isolation are critical for the success of islet transplantation. In particular, lot-to-lot variability significantly affects the yields of the isolation procedure. In this study, we have evaluated a new enzyme preparation in which highly purified collagenase can be blended with separately supplied neutral protease in a predetermined ratio. METHODS: We compared the results of human-islet isolations performed either with Collagenase NB1 supplemented with Neutral Protease NB (group I, n=9) or with Liberase (group II, n=9). RESULTS: Endotoxin contents of the enzyme preparations were lower in group I. Total islet yields were similar in both groups, but islet equivalents per gram of pancreas was higher in group I (4,020+/-1,240 vs. 2,360+/-1,350; P<0.05). Islet morphology was improved in group I with significantly higher proportion of free and intact islets (71+/-9% vs. 52+/-14%; P<0.01). In vitro function was improved and apoptosis rate was lower in group I. CONCLUSIONS: This new enzyme blend was as efficient as Liberase in terms of islet yields and showed improvements in islet morphology, viability, and in vitro function. The possibility to control lot-to-lot variability and the low endotoxin contents make Collagenase NB1 a promising product for human-islet isolation.
BACKGROUND: Biologic characteristics of enzyme products used for islet isolation are critical for the success of islet transplantation. In particular, lot-to-lot variability significantly affects the yields of the isolation procedure. In this study, we have evaluated a new enzyme preparation in which highly purified collagenase can be blended with separately supplied neutral protease in a predetermined ratio. METHODS: We compared the results of human-islet isolations performed either with Collagenase NB1 supplemented with Neutral Protease NB (group I, n=9) or with Liberase (group II, n=9). RESULTS: Endotoxin contents of the enzyme preparations were lower in group I. Total islet yields were similar in both groups, but islet equivalents per gram of pancreas was higher in group I (4,020+/-1,240 vs. 2,360+/-1,350; P<0.05). Islet morphology was improved in group I with significantly higher proportion of free and intact islets (71+/-9% vs. 52+/-14%; P<0.01). In vitro function was improved and apoptosis rate was lower in group I. CONCLUSIONS: This new enzyme blend was as efficient as Liberase in terms of islet yields and showed improvements in islet morphology, viability, and in vitro function. The possibility to control lot-to-lot variability and the low endotoxin contents make Collagenase NB1 a promising product for human-islet isolation.
Authors: P Pulimeno; T Mannic; D Sage; L Giovannoni; P Salmon; S Lemeille; M Giry-Laterriere; M Unser; D Bosco; C Bauer; J Morf; P Halban; J Philippe; C Dibner Journal: Diabetologia Date: 2012-12-15 Impact factor: 10.122
Authors: Kyle J Gaulton; Takao Nammo; Lorenzo Pasquali; Jeremy M Simon; Paul G Giresi; Marie P Fogarty; Tami M Panhuis; Piotr Mieczkowski; Antonio Secchi; Domenico Bosco; Thierry Berney; Eduard Montanya; Karen L Mohlke; Jason D Lieb; Jorge Ferrer Journal: Nat Genet Date: 2010-01-31 Impact factor: 38.330