EFFICIENT SEEDING OF SHEEP BONE MARROW-DERIVED MESENCHYMAL STEM CELLS (MSC) IN POLY(L-LACTIC ACID) SCAFFOLDS

Abstract

Hyaline cartilage is a support tissue with a poor capacity to self repair. In the last years, tissue engineering and cell therapy have focused its efforts in the development of scaffolds that may support the differentiation and the implantation of mesnechymal stem cells (MSC) in the site of lesions performed in femoral cartilage. Among synthetic materials used for the construction of these scaffolds, poly(L-lactic acid) (PLLA) is a suitable option, since some studies have offered promising results. The use of PLLA, nevertheles has an important handicap, as cell seeding easily results in a non uniform distribution and a poor density of cells, wich have been proposed as key steps for the differentiation of MSCs to chondrocytes. In our work we have cultured sheep MSCs, and proved its potentiallity by differentiation to chondrocytes in micromass culture. PLLA scaffolds 1 mm thick and 6 mm in diameter were characterized by determining their porosity and their mechanical properties, and subsequently were used to assay the seeding of MSCs. We measured efficiency and retention by quantification of DNA, and density and distribution by light microscopy of paraffin sections. Our results describe a simple technique of cell seeding by aspirating cells with a syringe that achieves a uniform distribution and a high density of cells. Finally 3D seeded MSCs were cultured with condrogenic medium containing TGF-β3 for 21 days and results analyzed by massons trichrome staining in paraffin embedded sections.