Transplantation of encapsulated neonatal porcine islet-like cluster cells into diabetic rats.
OBJECTIVE
To evaluate the function of alginate poly-L-ysine membrane in protecting porcine to rat islet xenografts.


METHODS
Newborn porcine islet-like cluster cells (ICC) were obtained by digesting pancreas with type XI collagenase. After 2-3 days' incubation, encapsulated ICC were formed through instrument. In vitro, insulin release and insulin stimulating test was performed. In vivo, encapsulated ICC were transplanted into streptozotocin-induced diabetic rats.


RESULTS
Unlike ICC only (insulin can be tested within 14 days) encapsulated ICC maintained insulin release at certain level for nearly 28 days. High insulin response to 16.7 mM glucose and 10 mM theophylline significantly differed from low insulin response to 5.6 mM or 16.7 mM glucose (P < 0.01). Extended survival of porcine ICC xenografts implanted in diabetic rats had been achieved by encapsulation. After transplantation, rats sustained normal glycemia for average 4 months. The capsules with ICC obtained from experimental group could be stained with neutral red. Insulin release of survival capsules with ICC in response to 16.7 mM glucose and 10 mM theophylline was 3 times more as compared to the insulin response to 5.6 mM glucose. Sections of encapsulated ICC (H&E) showed fairly good cell clusters and the membranes were generally free of fibrosis and host cell adherence.


CONCLUSIONS
Artificial membrane can protect discordant islet xenografts from rejection.
Chen
B
B
Clinical Research Institute, Beijing Friendship Hospital.
Liu
J
J
Zhu
X
X
Liu
X
X
D000818:Animals; D002470:Cell Survival; D003921:Diabetes Mellitus, Experimental / Q000601:surgery*; D016381:Islets of Langerhans Transplantation; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013552:Swine; D014183:Transplantation, Heterologous