Comparison of Bioartificial Pancreas Performance in the Bone Marrow Cavity and Intramuscular Space

Background and Aims: Bone marrow with a widely distributed and well-vascularized microenvironment that is capable of sustaining grafts is a potential site for islet transplantation. The femur bone marrow cavity offers sufficient space that may also receive the implantation of bioartificial pancreas (BAP). Methods: Mouse insulinoma cells encapsulating in agarose gel were further enclosed in a calcium phosphate cement chamber to create a BAP. BAPs implanted into the femur bone marrow cavity of diabetics were compared with those implanted in the intramuscular space. Blood glucose level and C-peptide were determined perioperatively. Results: The blood glucose level of the diabetics receiving BAPs in the intramuscular space decreased from 413 ± 24 to 285 ± 47 mg/dL at 1 day post-surgery. However, the blood glucose level returned to 398 ± 35 mg/dL with undetectable serum C-peptide at 2 weeks postoperatively that reveals implant failure. The blood glucose level of diabetics receiving BAPs into the femur bone marrow cavity decreased from 422 ± 32 to 247 ± 52 mg/dL and maintained in the range of 288 ± 47 mg/dL during the experimental period with an increase in C-peptide level from 6.1 ± 2.8 to 104.7 ± 16.4 pmol/L. Conclusions: This preliminary study indicates that the effectiveness of BAPs transplanted into the femur bone marrow cavity is superior to that implanted in the intramuscular space, which reveals the bone marrow may be a potential receptor site for the BAP transplantation.