A SIMPLE METHOD FOR CRYOPRESERVATION OF PURIFIED ADULT-PIG PANCREATIC-CELLS

Cryopreservation of islet cells may benefit many aspects of islet tran splantation including storage, transport of islets, immunomodulation, reduction of the exocrine contaminants. Isolation and purification of islets from large mammalian pancreases have been encountered by many p roblems, We reported an autodigestion method for preparation of adult pig pancreatic cells, In this paper, we describe a newly invented simp le method for cryopreservation of purified adult pig pancreatic cells, The viability and function of islet cells before (precryo.) and after (postcryo.) the cryopreservation procedure were compared, Islet cells harvested by the autodigestion method were suspended in cryoprotectan t ''Cell banker.'' A biofreezing vessel ''Bicell'' containing a cryoge nic vial with cell suspension was frozen at -80 degrees C. After 4 wk, the cryogenic vial was rapidly thawed in 37 degrees C water, the isle t cells were washed and cultured for overnight, Number of dithizone-st ained precryo. and postcryo. cells were 1.71 +/- 0.5 x 10(5) and 1.75 +/- 0.98 x 10(5) cells/pancreas respectively; therefore, the viability was 99%. Insulin release following high and low concentrations of glu cose in precryo. (12.02 +/- 3.63 ng/ml: low-glucose, 9.81 +/- 3.59 ng/ ml: high glucose) and postcryo. (5.57 +/- 4.03 ng/ml: low-glucose, 10. 24 +/- 8.88 ng/ml: high glucose) cells showed a marked improvement in response in postcryo. cells. The insulin content of precryo. and postc ryo. cells mere 914.4 +/- 277.4 and 93.6 +/- 15.4 ng/ml, respectively. This simple and efficient cryopreservation protocol may be applied fo r a large-scale storage of adult pig islet cells to establish an islet bank for transplantation.