Immunoisolation effect of polyvinyl alcohol (PVA) macroencapsulated islets in type 1 diabetes therapy.
Islet transplantation has shown great success in the treatment of type 1 diabetes since the Edmonton protocol was established. However, it still has two major problems to overcome: the lack of organ donors and the side effects of immunosuppression. Encapsulated islets have emerged as  a potential option for islet transplantation because it can, at least partly, overcome these two problems. Wistar rat islets suspended in 3% polyvinyl alcohol (PVA) hydrogel were frozen-thawed to make macroencapsulated islets (MEIs). The recovery rate, insulin content, and morphological change  in culture medium with/without fresh human plasma (FHP) were measured in MEIs and free islets in vitro. In vivo, MEIs of either Wistar or Lewis rats were transplanted into the peritoneal cavity of streptozotocin (STZ)-induced diabetic Lewis rats and nonfasting blood glucose (NFBG), body weight,  and histological evaluations were processed. FHP destroyed rat free islets but did not affect the islet morphology, islet recovery rate, or insulin content of rat MEIs. The transplantation of MEIs decreased the NFBG level and prevented body weight loss without a significant difference between  the donor strains. Insulin-positive islets were observed in PVA MEIs 24 weeks after allotransplantation. These results suggest that PVA MEIs may be used as a cure for type 1 diabetes.
Department of Histology and Embryology, Nankai University School of Medicine, Tianjin, China.
Zhi
Z
Qi
Chizuru
C
Yamamoto
Naomi
N
Imori
Ayano
A
Kinukawa
Kai-chiang
KC
Yang
Goichi
G
Yanai
Etsuko
E
Ikenoue
Yanna
Y
Shen
Yasumasa
Y
Shirouzu
Akihito
A
Hiura
Kazutomo
K
Inoue
Shoichiro
S
Sumi
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight / Q000187:drug effects; D002469:Cell Separation; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental / Q000473:pathology / Q000601:surgery*; D006084:Graft Rejection / Q000276:immunology; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000166:cytology* / Q000187:drug effects / Q000473:pathology; D016381:Islets of Langerhans Transplantation; D008297:Male; D010949:Plasma / Q000737:chemistry; D011142:Polyvinyl Alcohol / Q000494:pharmacology*; D051381:Rats; D011917:Rats, Inbred Lew; D017208:Rats, Wistar
D001786:Blood Glucose; D007328:Insulin; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011142:Polyvinyl Alcohol