Histochemical examination of adipose derived stem cells combined with β-TCP for bone defects restoration under systemic administration of 1α,25(OH)2D3

The purpose of this study was to evaluate the effects of osteogenic differentiated adipose-derived stem cell (ADSC) loaded beta-tricalcium phosphate (beta-TCP) in the restoration of bone defects under intraperitoneal administration of 1 alpha,25-dihydroxyvitamin D3(1 alpha,25 (OH)(2)D-3). ADSCs were isolated from the fat tissue of 8 week old Wister rats and co-cultured with beta-TCP for 21 days under osteogenic induction. Then the ADSC-13-TCP complexes were implanted into bone defects in the femora of rats. 1 alpha,25(OH)(2)D-3 (VD) or normal saline (NS) was administrated intraperitoneally every other day after the surgery. Femora were harvested at day 7, day 14 and day 28 post-surgery. There were 4 groups for all specimens: beta-TCP-NS group; beta-TCP-ADSC-NS group; beta-TCP-VD group and beta-TCP-ADSC-VD group. Alkaline phosphatase (ALP) was up-regulated obviously in ADSC groups compared with non-ADSC groups at day 7, day 14 and day 28, although high expression of runt-related transcription factor 2 (RUNX2) was only seen at day 7. Furthermore, the number of TRAP-positive osteoclasts and the expression of cathepsin K (CK) were significantly decreased in VD groups compared with non-VD groups at day 7 and day 14. As a most significant finding, the beta-TCP-ADSC-VD group showed the highest BV/TV ratio compared with the other three groups at day 28. Taken together, ADSC-loaded beta-TCP under the administration of 1 alpha,25(OH)(2)D-3 made a promising therapy for bone defects restoration. (C) 2015 Elsevier B.V. All rights reserved.