title: High-yield isolation, expansion, and differentiation of rat bone marrow-derived mesenchymal stem cells with fibrin microbeads.
abstract: Fibrin microbeads (FMB), made of extensively cross-linked dense and partially denatured fibrin, were used as a matrix for efficient isolation of mesenchymal stem cells (MSC) from rat bone marrow (BM). After 2 days of incubation of FMB with whole BM in suspension, a high number of cells of mesenchymal origin attached to the FMB. On the 14th day after their transfer to plastic, the yield of the cells isolated via FMB was approximately 3-4 times higher than that obtained by currently used protocols based solely on plastic adhesion. This implies that the number of MSC in BM may be higher than previously reported. FACS analyses and immunostaining showed the mesenchymal characteristics of these cells by positive staining for fibronectin, vimentin, CD49E, and CD29. Immediately after isolation, less than 20% of the cells still expressed the hematopoietic markers CD11b and CD45. Most of these cells were eventually eliminated after further expansion of the isolated cells on plastic. Cells isolated via FMB were expanded in culture for more than 4 months and could be defined as MSC along this time period based on their ability to differentiate into precursors of mesenchymal tissues, such as osteogenic, adipogenic, and chondrogenic cells. Similar differentiation plasticity was observed in clones derived from single cells from whole MSC populations isolated via FMB. Based on our results we propose that FMB can serve as a 3-dimensional biodegradable matrix for isolation, differentiation, and possibly implantation of MSC for tissue regeneration.
authors.affiliation: Biotechnology and Radiobiology Laboratory, Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
authors.forename: Lior
authors.initials: L
authors.lastname: Zangi
authors.forename: Rachel
authors.initials: R
authors.lastname: Rivkin
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Kassis
authors.forename: Lilia
authors.initials: L
authors.lastname: Levdansky
authors.forename: Gerard
authors.initials: G
authors.lastname: Marx
authors.forename: Raphael
authors.initials: R
authors.lastname: Gorodetsky
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D002469:Cell Separation; D005337:Fibrin; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology*; D008863:Microspheres; D051381:Rats; D017208:Rats, Wistar; D023822:Tissue Engineering
chemical_list: D005337:Fibrin