Caplan reviewed how a small pool of mesenchymal stem cells gives rise to bone and cartilage, and proposed using a patient's own expanded cells for skeletal repair.
Narrative review of embryonic and adult mesenchymal cell studies from the Skeletal Research Center at Case Western Reserve University.
Methods
Scope
Embryonic and adult mesenchymal stem cell lineage biology
Proposed use in skeletal repair
Topics
Chondrogenic and osteogenic lineages
Vascularity and cell fate
Culture seeding density
Adult stem cell sources
Culture‑expanded human marrow cells
Self‑cell repair
Key Points
Caplan proposed that a small pool of mesenchymal stem cells supplies the cells that build bone and cartilage in the embryo and repair them in the adult, with their progeny moving through discrete lineage steps to tissue‑specific end‑stage cells.
A hypothetical chondrogenic lineage map has at least five stages, and, separately, every experiment to slow or reverse the programmed age‑dependent biosynthetic changes of end‑stage chondrocytes has failed.
Embryonic chick limb mesenchymal cells in 35‑mm dishes formed bone best at a seeding density of 2×10⁶ cells, vs 5×10⁶ cells for cartilage.
Caplan identified marrow, periosteum and muscle connective tissue as the adult repositories of mesenchymal stem cells.
Culture‑expanded human marrow‑derived mesenchymal cells implanted subcutaneously in nude mice formed bone in every sample tested.
Caplan proposed that harvesting, expanding and delivering a patient's own stem cells to a target site could drive fast, tissue‑specific skeletal repair.
Board pearl
Vascularity decides the lineage: bone forms close to blood vessels, while cartilage forms only where vessels are entirely absent.
Authors' conclusion
The study of these mesenchymal stem cells, whether isolated from embryos or adults, provides the basis for the emergence of a new therapeutic technology of self-cell repair. The isolation, mitotic expansion, and site-directed delivery of autologous stem cells can govern the rapid and specific repair of skeletal tissues.
Caplan reviewed how a small pool of mesenchymal stem cells gives rise to bone and cartilage, and proposed using a patient's own expanded cells for skeletal repair.
Narrative review of embryonic and adult mesenchymal cell studies from the Skeletal Research Center at Case Western Reserve University.
Methods
Scope
Embryonic and adult mesenchymal stem cell lineage biology
Proposed use in skeletal repair
Topics
Chondrogenic and osteogenic lineages
Vascularity and cell fate
Culture seeding density
Adult stem cell sources
Culture‑expanded human marrow cells
Self‑cell repair
Key Points
Caplan proposed that a small pool of mesenchymal stem cells supplies the cells that build bone and cartilage in the embryo and repair them in the adult, with their progeny moving through discrete lineage steps to tissue‑specific end‑stage cells.
A hypothetical chondrogenic lineage map has at least five stages, and, separately, every experiment to slow or reverse the programmed age‑dependent biosynthetic changes of end‑stage chondrocytes has failed.
Embryonic chick limb mesenchymal cells in 35‑mm dishes formed bone best at a seeding density of 2×10⁶ cells, vs 5×10⁶ cells for cartilage.
Caplan identified marrow, periosteum and muscle connective tissue as the adult repositories of mesenchymal stem cells.
Culture‑expanded human marrow‑derived mesenchymal cells implanted subcutaneously in nude mice formed bone in every sample tested.
Caplan proposed that harvesting, expanding and delivering a patient's own stem cells to a target site could drive fast, tissue‑specific skeletal repair.
Board pearl
Vascularity decides the lineage: bone forms close to blood vessels, while cartilage forms only where vessels are entirely absent.
Authors' conclusion
The study of these mesenchymal stem cells, whether isolated from embryos or adults, provides the basis for the emergence of a new therapeutic technology of self-cell repair. The isolation, mitotic expansion, and site-directed delivery of autologous stem cells can govern the rapid and specific repair of skeletal tissues.