Effect of a new drug releasing system on microencapsulated islet transplantation.

ABSTRACT

OBJECTIVE: This study aimed to develop a novel release system for grafted islets. MATERIALS AND METHODS: A graphene oxide-FTY720 release system was constructed to test the drug loading and releasing capacity. The recipient rats were divided into four groups as following Experiment group A (EG A) and B (EG B); Control group A (CG A) and B (CG B). In each group, (2000 ± 100) IEQ microencapsulated islets were implanted into the abdominal cavity of the recipients with oral FTY720, local graphene oxide-FTY720 injection, without immunosuppressants, and with graphene oxide-saturated solution respectively. We detected the immunological data, the blood glucose level, and pericapsular overgrowth to show the transplantation effect. RESULTS: 31% of adsorptive FTY720 was released within 6 h, and 82% of FTY720 was released within 48 h. From day 5 to 8, the amount of PBL in EG B was significantly less than those in EG A (P<0.01). The CD3+ and CD8+ T lymphocytes were suppressed 3 days longer in EG B than in EG A. On day 19 posttransplantation, the blood glucose level in EG B was much lower than that in EG A (P<0.01). On the same day, pericapsular overgrowth was grade I in EG B, grade II in other groups. CONCLUSIONS: Graphene oxide-FTY720 complex showed a drug releasing effect. Local application of graphene-FTY720 releasing system could decrease the amount of peripheral blood lymphocytes (PBL) and the percentage of CD3 and CD8 T lymphocytes in blood for longer time than oral drug application. This releasing system could achieve a better blood glucose control.