Liposomal Formulations of Tacrolimus and Rapamycin Increase Graft Survival and Fiber Outgrowth of Dopaminergic Grafts

Cell Transplantation

Article

Aylin Y. Alemdar¹  Damaso Sadi¹  Ivar Mendez²  Vivian C. Mcalister³ 

[1] Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4H7;Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4H7;Department of Surgery, Division of Neurosurgery, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4H7;Department of Surgery, Division of General Surgery, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 2Y9;

关键词: Transplantation;    Parkinson's disease;    Tacrolimus;    Rapamycin;    Liposomes;   

DOI  :  10.3727/000000004783983936

来源: Sage Journals

【 摘 要 】

The immunosuppressive drugs tacrolimus (TAC) and rapamycin (RAPA) have both been found to have neuroprotective effects on dopaminergic neurons. The purpose of the present study was to investigate whether liposomal formulations of these drugs administered directly into the brain improve cell survival and fiber outgrowth. Rats with unilateral 6-hydroxydopamine lesions were transplanted with 800,000 fetal rat ventral mesencephalic cells and randomly divided to one of four groups. Group 1 received a transplant containing cells only; group 2 received a cell suspension containing 0.68 μM liposomal RAPA (LRAPA); group 3 received a cell suspension containing 2.0 μM liposomal TAC (LTAC); and group 4 received a cell suspension containing a liposomal formulation of both 0.68 μM RAPA and 2.0 μM TAC (LRAPATAC). Rats were sacrificed after 6 weeks, and cell survival and fiber outgrowth were assessed using tyrosine hydroxylase (TH) immunohistochemistry. The animals receiving a cell suspension containing either LTAC or LRAPATAC were found to have significantly more surviving TH-immunoreactive (TH-ir) cells than the control group receiving cells only. The group receiving LTAC had significantly longer fibers, the group receiving LRAPA had significantly more fibers close to the graft, and the group receiving LRAPATAC had significantly more fibers at all distances. This study shows the feasibility of using liposomal formulations of neuroimmunophilins directly in the brain at the time of implantation to improve graft survival and fiber outgrowth. Furthermore, we have shown that the combination of LTAC and LRAPA has a synergistic effect. These compounds may play an important role in optimizing graft survival and host reinnervation in cellmediated brain repair strategies for the treatment of neurological conditions.

【 授权许可】

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