Abstract
Background aims. Stromal vascular fractions (SVF) from adipose tissue have heterogeneous cell populations, and include multipotent adipose-derived stem cells. The advantages of using of SVF include the avoidance of an additional culture period, a reduced risk of extensive cell contamination, and cost-effectiveness. Methods. Unilateral 20-mm mid-diaphyseal segmental defects in rabbit ulna were treated with one of the following: polylactic glycolic acid (PLGA) scaffold alone (group 1, control), a PLGA scaffold with undifferentiated SVF cells (group 2), or a PLGA scaffold with osteogenically differentiated SVF cells (group 3). At 8 weeks after implantation, five rabbits in each treatment group were killed to assess bone defect healing by plain radiography, quantitative microcomputed tomography and histology. Results. The SVF cells were well grown on PLGA scaffolds and expressed type I collagen and alkaline phosphatase (ALP). The intensity of ALP and OPN gene expressions in osteogenic medium culture were increased from 14 days to 28 days. In vivo evaluations at 8 weeks showed that treatment of SVF cells with or without osteogenic differentiation resulted in more bone formation in the critically sized segmental defects than PLGA scaffold alone. Osteogenically differentiated SVF cells significantly enhanced bone healing compared with undifferentiated SVF cells. Conclusions. Adipose-derived stromal SVF showed osteogenic potential in vitro. Accordingly, SVF could provide a cell source for bone tissue engineering. However, treatment with uncultured SVF cells on bone healing was not satisfactory in the in vivo animal model.
Acknowledgments
The authors would like to thank Sung-Eun Kim, PhD, Hyo-Keun Kim and You-Jin Ko for their technical assistance, Keun-Poong Kim, Mi-Jung Shin, Jin-Young Jung (REGEN Biotech) for performing the cell preparation, Jong-Young Kim and Jin-Hyung Shim (POSTECH) for fabricating the scaffolds, and the Department of Pathology, Korea University Guro Hospital, for performing the histologic evaluation. In addition, we extend our thanks to Dr John Roberts for English editing. This work was partially supported by the National Research Foundation of Korea (NRF) funded by the Korea government (MEST) (grant number 2010-0018294).
Declaration of interest: The authors have no conflicts of interest to declare.
Notice of correction
The Early Online version of this article posted online 18 Nov 2011 contained an error on page 6.
The legend to figure 5 “RT-PCR analysis of osteogenic marker. Five micrograms of total RNA isolated from cells cultured in (CM) and (OM) were used for the synthesis of single-stranded DNA. Expression of osteogenicspecific genes was analyzed by RT-PCR at different time-points.”
should have read
“Plain radiographs showing bone formation in the segmental defect of rabbit ulna. New bone formation from one or both ends of the defect was observed in each group at 4 weeks after implantation. Group 3 (a PLGA scaffold with osteogenically differentiated rSVF cells) had callus formation in the central area of defect. At 8 weeks after implantation, group 3 showed the defect bridging, while groups 1 (a PLGA scaffold alone) and 2 (a PLGA scaffold with undifferentiated rSVF cells) did not.”
This has been corrected in this version.