IJUP08 - Universidade do Porto

Comparison of the in vivo bone forming activity of osteogenicinduced
mesenchymal stem cells derived from adipose tissue
and bone marrow
T. Ribeiro 1,2 , C. Bessa Pereira 1,2 , P. Gomes 2 and M.H. Fernandes 2
1 Faculty of Sciences, University of Porto, Portugal
2 Faculty of Dental Medicine, University of Porto, Portugal
Adipose tissue contains pluripotent stem cells able to osteogenic differentiation. These
cells are ease to harvest in large amounts for autologous transplantation and present high
proliferation rates for ex vivo expansion, making them attractive for bone tissue
engineering approaches. The aim of this work is to compare the bone forming activity of
mesenchymal stem cells from adipose tissue and bone marrow, after in vitro expansion
over supportive scaffolds and subcutaneous implantation of the cell-material constructs in
a rat model. As the vascularisation in the local environment plays a key role in the bone
formation events, the angiogenesis response elicited in the different experimental
conditions is also evaluated.
Stem cells derived from subcutaneous adipose tissue and bone marrow are obtained from
3-months-old Wistar rats, following standard procedures. Culture is performed in -
minimum essential medium containing 10% fetal bovine serum, antibiotics and 50 g/ml
ascorbic acid, both in the absence and in the presence of 10 nM dexamethasone, a classic
osteoblastic inducer. Cells of the first passage are cultured on clinically approved scaffolds
in a combination of non-induced and osteogenic-induced conditions, following
subcutaneous implantation in athymic nude mice. Prior to in vivo implantation, the cellmaterial
constructs are characterized for cell growth and expression of osteoblastic
differentiation markers. At defined time-points after implantation (typically, two and 12
weeks), the cell constructs with surrounding tissue are harvested, along with selected
organs, and subject to histological evaluation regarding the expression of bone matrix
proteins, bone forming activity and angiogenesis response.
Preliminary results show that mesenchymal stem cells derived from rat adipose tissue
present a high proliferation rate over several scaffolds, both ceramic-based and polymeric
materials. Dexamethasone induces significant effects on cell growth rate and osteoblastic
differentiation profile. At the same experimental conditions, bone marrow-derived
mesenchymal stem cells appear to exhibit a higher osteogenic in vitro potential. In vivo
studies are in course.
The forthcoming results are expected to contribute to a more complete characterization of
adipose tissue-derived mesenchymal stem cells regarding their suitability for tissue
engineering applications in the repair or replacement of diseased and/or damaged bone
tissue.
References:
[1] Zuk, P.A., Zhu, M., Mizuno, H., et al (2001), Multilineage cells from human adipose tissue:
implications for cell-based therapies, Tissue Engineering, 7, 211-228.
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