Mesenchymal stem cells and supports for tissue regeneration, repair and reconstruction

摘要

Materials and methods for preparing mesenchymal stem cells are described such that the mesenchymal stem cells remain for a longer period of time than would normally be found at a site of tissue healing. The mesenchymal stem cells are pretreated to exhibit osteogenic characteristics and, when combined with extracellular matrix components produced from the pretreated cells, improve tissue healing. Co-administration of the pretreated cells and their secreted extracellular matrix components at an injured site or defect allowed the mesenchymal stem cells to co-localize at or near the injured or defect site for a longer period. The combination improves overall repair of the tissue by extending the retention signal of mesenchymal stem cells. A three-dimensional scaffold containing the pretreated cells with or without addition of the secreted extracellular matrix is also described. The conditioned scaffold is suitable for use in vivo and may be preserved cryogenically prior to use.

主权项

1. A composition for repair or reconstruction of bone tissue, wherein the composition is produced by:
A) culturing mesenchymal stem cells for 5 to 14 days in a culture medium lacking dexamethasone, the culture medium comprising an effective amount of a peroxisome proliferator-activated receptor gamma (PPAR-γ) inhibitor, the culturing so as:
(i) to inhibit regulation of adipogenesis in the mesenchymal stem cells;(ii) to induce the mesenchymal stem cells to exhibit: (a) early or primitive osteogenic differentiation without terminal differentiation; (b) an upregulation in gene expression for collagen types I, III, V, VI, XI, and XII, and (c) downregulation or depletion of cytosolic glycogen synthase kinase 3β; and(iii) to not induce mineralization; B) seeding the mesenchymal stem cells onto a three-dimensional scaffold, wherein the three-dimensional scaffold is produced from living cells; and C) allowing the cultured mesenchymal stem cells to produce and secrete an extracellular matrix mixture comprising insoluble components onto the three-dimensional scaffold, the insoluble components including collagen types I, III, V, VI, XI, and XII.