Successful human islet isolation utilizing recombinant collagenase.

Area of Science:

• Biochemistry
• Cell Biology
• Transplantation Science

Background:

• Enzymatic dissociation of pancreatic acinar tissue using collagenase is critical for isolating pancreatic islets.
• Variability in collagenase batch activity hinders reproducible islet isolation.
• Recombinant proteases offer a potential solution for consistent enzyme activity.

Purpose of the Study:

• To evaluate the efficacy of a recombinant collagenase blend compared to Liberase HI for human islet isolation.
• To assess differences in islet yield, purity, fragmentation, and viability between the two enzyme preparations.
• To determine the functional capacity and in vivo performance of islets isolated with recombinant collagenase.

Main Methods:

• Human pancreases from multiorgan donors were subjected to digestion-filtration for islet isolation.
• Enzyme treatments included Liberase HI (n=51) and a recombinant collagenase blend (n=25).
• Assessed islet yield, exocrine tissue attachment, purity, islet equivalents to number ratio, and viability. Evaluated insulin release and performed islet transplantation into diabetic nude mice.

Main Results:

• No significant differences in islet yield, exocrine-attached islets, or final purity were observed.
• Islets isolated with recombinant collagenase showed significantly less fragmentation (islet equivalents/islet number ratio, P < 0.01).
• Liberase HI resulted in slightly higher islet viability (92.3% vs. 85.6%, P < 0.05), with comparable insulin release and successful normoglycemia post-transplantation.

Conclusions:

• Viable human islets can be successfully isolated using a recombinant collagenase blend.
• Recombinant collagenase offers reduced islet fragmentation and potential for improved isolation reproducibility.
• Further optimization of recombinant collagenase blends could enhance consistency in islet isolation for therapeutic applications.