Cartilage tissue engineering using electrospun PCL nanofiber meshes and MSCs

Mesenchymal stem cells (MSCs) have been recognized for their ability to differentiate into cells of different tissues such as bone, cartilage, or adipose tissue, and therefore are of great interest for potential therapeutic strategies. Adherent, colony-forming, fibroblastic cells were isolated from human bone marrow aspirates, from patients undergoing knee arthroplasties, and the MSCs phenotype characterized by flow cytometry. Afterward, cells were seeded onto electrospun polycaprolactone nanofiber meshes and cultured in a multichamber flow perfusion bioreactor to determine their ability to produce cartilagineous extracellular matrix. Results indicate that the flow perfusion bioreactor increased the chondrogenic differentiation of hBM-MSCs, as confirmed either by morphological and RT-PCR analysis. Cartilage-related genes such as aggrecan, collagen type II, and Sox9 were expressed. ECM deposition was also detected by histological procedures. Collagen type II was present in the samples, as well as collagen type I. Despite no statistically significant values being obtained for gene expression, the other results support the choice of the bioreactor for this type of culture.M. Alves da Silva would like to acknowledge the Portuguese Foundation for Science and Technology (FCT) for her grant (SFRH/BD/28708/2006). The authors would like to acknowledge the patients of Hospital de S. Marcos, Braga, Portugal, for the donation of the biological samples, as well to its medical staff. The authors would also like to thank the Institute for Health and Life Sciences (ICVS), University of Minho, Braga, Portugal, for allowing the use of their research facilities. Authors would like specially to acknowledge Luis Martins for his valuable help with the histological procedures and Goreti Pinto for the aid in the microscopy. We thank Ana M. Frias for the important help with the FACS procedure. Finally, we would like to acknowledge the European NoE EXPERTISSUES (NMP3-CT-2004-500283). This work was partially supported by the European FP7 Project Find and Bind (NMP4-SL-2009-229292)