Evaluation of osmolality of density gradient for human islet purification.
For pancreatic islet transplantation, the most common method of islet purification is density gradient centrifugation because of the differences in density between islets and acinar tissue. The density of islets/acinar tissue depends on several conditions, such as osmolality of purification  solution. In this study, we evaluated the osmolality of iodixanol-controlled density gradients (400, 450, and 500 mOsm/kg) on the islet purification step. The density of the purification solutions was controlled by changing the volumetric ratio of iodixanol and the purification solutions (iodixanol-Kyoto  solutions; IK solutions). The osmolality of density gradients was controlled by addition of 10× Hanks balanced salt solution (HBSS) solution. Density of both islets and acinar tissue increased relative to increase of the osmolality of purification solutions. There were no significant  differences among the three groups on islet yield after density-adjusted purification and the rate of postpurification recovery. In vitro and in vivo assays suggest that the quality of islets was similar among the three groups. Our data suggest that efficacy of purification and quality of  isolated islets is similar when the osmolality of purification solutions is between 400 and 500 mOsm/kg and density adjustment is applied. Since the density of islet and acinar tissue is changed according to osmolality, the density adjustment is important when using several osmolality solutions.
Baylor All Saints Medical Center, Baylor Research Institute, Fort Worth, TX, USA. noguchih2006@yahoo.co.jp
Hirofumi
H
Noguchi
Bashoo
B
Naziruddin
Masayuki
M
Shimoda
Yasutaka
Y
Fujita
Daisuke
D
Chujo
Morihito
M
Takita
Han
H
Peng
Koji
K
Sugimoto
Takeshi
T
Itoh
Naoya
N
Kobayashi
Nicholas
N
Onaca
Marlon F
MF
Levy
Shinichi
S
Matsumoto
D000328:Adult; D002469:Cell Separation / Q000379:methods*; D002470:Cell Survival / Q000187:drug effects; D002499:Centrifugation, Density Gradient; D005260:Female; D005942:Gluconates / Q000494:pharmacology; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology; D007515:Islets of Langerhans / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D010710:Phosphates / Q000494:pharmacology; D014199:Trehalose / Q000494:pharmacology; D014283:Triiodobenzoic Acids / Q000494:pharmacology
C087059:ET-Kyoto solution; D005942:Gluconates; D006895:Hydroxyethyl Starch Derivatives; D010710:Phosphates; D014283:Triiodobenzoic Acids; D014199:Trehalose; C044834:iodixanol