P-201

In vitro evaluation of young porcine islet isolation protocol using adult pigs

M. Lamb, K. Laugenour, O. Liang, E. Steward, S. Li, J. Lakey
University of California Irvine Medical Center, Surgery, Orange, USA

Objective: We have recently developed a novel, scalable procedure for the isolation and maturation of porcine pancreatic islets in vitro. In this study, we evaluated this protocol with the standard market-weight pigs that has been primarily used for islet xenotransplantation research.

Methods: Porcine pancreases (mean age, 6 ± 1 month) were recovered using rapid surgical procurement. Islets were isolated from a 5 gram portion of the tail of the pancreas using CIzyme collagenase MA/BP protease (Vitacyte Inc) and then cultured at 37^oC and 5% CO₂ for 7days. Viability was assessed using FDA/PI and function using glucose stimulated insulin release (GSIR) assay. Results were compared to isolations from young porcine pancreases (mean age 20 days) performed using the identical experimental protocols.

Results: Islet yield (IE) from the market-weight pig pancreas immediately post isolation was 10.2x10³ ± 324 IE (mean ± sem) with 85.1 ± 0.5% viability which decreased to 7.5x10³ ± 63 IE and 73.7 ± 0.6% viable at 1 week of culture. This compared to 12.6x10³ ± 183 and 97 ± 0.1% viable at day 1 and subsequent increase to 33.3x10³ ± 136 and 92 ± 0.4% viable after 7 days of maturation in the tissue obtained from the young pig pancreas.

Conclusions: Functional viability using GSIR was 1.5 ± 0.1 (SI, ratio of insulin during high glucose stimulation/low basal) in the market weight pig at day 7 post isolation compared to 2.4 ± 0.1 (day 1) and 2.6 ± 0.2 (day 7) observed in the islets matured from young pig pancreas. The results demonstrate that our unique protocol for young pig pancreas is ineffective in the large market-weight pig using current protocols.

P-201

In vitro evaluation of young porcine islet isolation protocol using adult pigs

M. Lamb, K. Laugenour, O. Liang, E. Steward, S. Li, J. Lakey
University of California Irvine Medical Center, Surgery, Orange, USA

Objective: We have recently developed a novel, scalable procedure for the isolation and maturation of porcine pancreatic islets in vitro. In this study, we evaluated this protocol with the standard market-weight pigs that has been primarily used for islet xenotransplantation research.

Methods: Porcine pancreases (mean age, 6 ± 1 month) were recovered using rapid surgical procurement. Islets were isolated from a 5 gram portion of the tail of the pancreas using CIzyme collagenase MA/BP protease (Vitacyte Inc) and then cultured at 37^oC and 5% CO₂ for 7days. Viability was assessed using FDA/PI and function using glucose stimulated insulin release (GSIR) assay. Results were compared to isolations from young porcine pancreases (mean age 20 days) performed using the identical experimental protocols.

Results: Islet yield (IE) from the market-weight pig pancreas immediately post isolation was 10.2x10³ ± 324 IE (mean ± sem) with 85.1 ± 0.5% viability which decreased to 7.5x10³ ± 63 IE and 73.7 ± 0.6% viable at 1 week of culture. This compared to 12.6x10³ ± 183 and 97 ± 0.1% viable at day 1 and subsequent increase to 33.3x10³ ± 136 and 92 ± 0.4% viable after 7 days of maturation in the tissue obtained from the young pig pancreas.

Conclusions: Functional viability using GSIR was 1.5 ± 0.1 (SI, ratio of insulin during high glucose stimulation/low basal) in the market weight pig at day 7 post isolation compared to 2.4 ± 0.1 (day 1) and 2.6 ± 0.2 (day 7) observed in the islets matured from young pig pancreas. The results demonstrate that our unique protocol for young pig pancreas is ineffective in the large market-weight pig using current protocols.