[Cryopreservation of microencapsulated rat islets].
OBJECTIVE
To investigate the role of alginate-polylysine-alginate (APA) microcapsules in protecting rat islet cells in cryopreservation.


METHODS
Purified rat islet cells microencapsulated with APA and free islet cells were cryopreserved for one month and then thawed for culture in RPMI 1640 overnight. The morphology of the cells was observed and their function assessed by stimulated insulin release test.


RESULTS
APA microcapsulation protected the fragile islets from freezing damage by increasing the recovery rate of the cells from 68.6%+/-2.9% to 94.7%+/-1.4% (P<0.05). After incubation with high glucose (16.7 mmol/L) solution, the insulin release from the encapsulated cells after cryopreservation significantly increased in comparison with that of the nonencapsulated cells (22.6+/-1.8 mU/L vs 11.7+/-1.5 mU/L, P<0.05). In high glucose solution containing theophylline, the calculated stimulation index of the encapsulated cells was about 3 times that of the nonencapsulated cells.


CONCLUSIONS
APA microencapsulation may significantly increase the post-thaw recovery and improve the function for cryopreserved rat islets.
Hou
Jun
J
Center of Renal Transplantation, First Hospital of Xi'an Jiangtong University, Xi'an 710061, China. houjundoctor@sina.com
Xue
Wu-jun
WJ
Tian
Xiao-hui
XH
Pang
Xin-lu
XL
Teng
Yan
Y
Feng
Xin-shun
XS
D000464:Alginates / Q000494:pharmacology; D000818:Animals; D002214:Capsules; D002469:Cell Separation; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods*; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism; D008297:Male; D011107:Polylysine / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D000464:Alginates; D002214:Capsules; D007328:Insulin; C051546:alginate-polylysine-alginate; D011107:Polylysine