Comparative Characterisation of Placental and Amniotic Fluid-derived stem cells

Objective: Tissue engineering technologies offer great potential to provide graft tissues for maxillofacial reconstruction. The potential use of embryonic and foetal-derived stem cells for tissue regeneration has generated much interest in the field, as these cells are pluripotent allowing them to be differentiated into many different cell types. The amniotic membrane of the placenta and amniotic fluid offer less invasive sources of foetal stem cells which may be useful for regenerative medicine technologies. Currently, bone-marrow-derived stem cells are often used in skeletal tissue engineering. The objective of this study was to compare human amnion (HAM), amniotic fluid (HAF)-derived stem cells with bone marrow-derived MSCs (BM-MSCs) for their chondrogenic potential for cartilage tissue engineering. Methods: PGA scaffolds were seeded with HAM, HAF or BM-MSCs. The resultant cell/scaffold constructs were cultured for 4 weeks in classical chondrogenic media. At 2 and 4 weeks, constructs were taken for analysis by real-time PCR (to measure gene expression of characteristic cartilage proteins). At 4 weeks, constructs were also taken for histochemical and immunochemical analysis of the extracellular matrix. Results: Constructs formed from BM-MSCs accumulated the most extracellular matrix and showed extensive distribution of collagen II and proteoglycan compared to HAF or HAM constructs. BM-MSCs also showed the highest expression of markers for hyaline cartilage and accumulation of GAG. HAM cells did not express collagen II nor aggrecan. BM-MSCs also showed the highest expression of the hypertrophic cartilage marker, collagen X. Conclusions: Under the conditions used, BM-MSCs were the more appropriate stem cell type for hyaline cartilage tissue engineering but displayed a tendency to hypertrophy. Acknowledgements: This collaborative research would not have been possible without funding from the European Commission which established the EXPERTISSUES Network of Excellence [reference 500283]. A.M. Frias is recipient of a post-doctoral scholarship from Fundação para a Ciência e Tecnologia (SFRH/BPD/45206/2008)