Development of mesenchymal stem cell-implant complexes by cultured cells sheet enhances osseointegration in type 2 diabetic rat model

This study investigated the hypothesis that a mesenchymal stem cells (MSC)-implant complex could be used in type 2 diabetic rats. Diabetes was modeled with type 2 diabetic rats induced by high fat diet with low dose streptozotocin (STZ) injected intraperitoneally. MSC sheets were harvested from culture flasks, wrapped around implants to construct the complexes, and then cultured in an osteogenic medium. The layered cell sheets integrated well with the implants and remained viable, with small mineralized nodules visible on the implant surfaces after culturing. The MSC-implant complexes were inserted into the right tibiae of the diabetic rats. Titanium implants served as controls. After four and eight weeks of healing, the tibiae were observed via MicroCT and harvested for histological examination. For the MSC-implant complexes, MicroCT analysis showed that bone volume ratio and trabecular thickness increased significantly (p<0.05), and trabecular separation decreased significantly (p<0.05) compared to the titanium implants in diabetic rats. Histological examination revealed a greater amount of new bone tissue forming around the MSC-implant complexes and a higher bone implant contact (BIC) rate than the titanium implants. These findings demonstrate that MSC-implant complexes possess osteogenic abilities and can be used in diabetic rats to improve the BIC rate. Thus, MSC-implant complexes provide a novel tissue engineering approach that promotes osseous healing and may potentially be useful in the treatment of diabetic patients. (C) 2011 Elsevier Inc. All rights reserved.