Candidate cell sources for regenerative medicine include:1. ES cells, 2. Fetal cells, and 3. Adult stem cells.

Umezawa, A., et al.. Mol. Cell. Biol. 11: 920-927, 1991

Marrow stroma serves a microenvironment or nichefor hematopoietic cells

Fat Neuron

Bone

Cartilage

Cardiomyocyte

Skeletal myocyte

Default Default With exposure to inducesWith exposure to induces

Differentiated phenotypes of marrow stromal cells

ねずみ５匹ねずみ５匹エックス線写真エックス線写真

4 weeks

2 weeks

In vivoIn vivo osteogenic activity in marrow stromal cells osteogenic activity in marrow stromal cells

The injected cells generated bone

Generation of a delayed union modelGeneration of a delayed union modelA 5-mm section of syngeneic mouse femur at the diaphysis was removed.A 5-mm section of syngeneic mouse femur at the diaphysis was removed.

Bone was not formed without any treatment

Marrow stromal cells as a source of cell therapy

４週4 weeks

The generated bones were transplanted into the femur bone defects.

PLGA sheets

CollagenCollagenmicrospongemicrosponge

overlay the interstices of overlay the interstices of the fabricated web-likethe fabricated web-like

Generation of bone tissue of desired sizes and shapesSheet-style biodegradable polymer, PLGA (200 um thick,) as a scaffold

Hybridization of the PLGAwith collagen microsponge

4.3 mm

KUSA cells on PLGA/COL

Laminating mesh sheets on bone defect

4W

8W

40x 100x

Cell transplantation with PLGA/COL mesh

Strategy for Bone Tissue Engineering

Implantation to bone defect site adapted to various shape

growth factor hybrid

PLGA/collagen mesh cell seeding

apatite hybrid

laminate

curl

roll

The cell-seeded sheets were rolled up around a silicone rod,and cultivated in vivo for 4 weeks at the subcutaneous tissue.

Cylinder-shaped bone

Bone knotsbone of more complex shapes

We can control bone shape completely

Mimic shaping of phalanges from -TCP blockβ

TransplantationOsteoblast seeded mesh

Cover the β-TCP corewith meshChondrocyte seeded mesh

Strategy for bone tissue engineering

Generation of phalanges by the PLGA hybrid sheet with marrow-derived mesenchymal cells.

phelage-like bone

Thumb of the graduate student

2W 4W

8W

Implantation of MSC-x Pellet into the subcutaneous tissue of immunodeficient mice

Enchondral Ossification

Implantation of MSC-x pelleted micromasses in the nude mice

2W 4W 8W

Toluidine blue stain

HE

Enchondral Ossification

2W 4W 8W

Toluidine blue stain

HE

Implantation of MSC-x pelleted micromasses in the nude mice

Enchondral Ossification

Selection by chondrocyte- and osteoblast-specific cis-regulatory element

pCS2-Venus

p742-Venus

UE7T-9 UE7T-13

UE6E7T-12 UBE6T-6

OSE cis-regulatory activityChondrocyte-specific

cis-regulatory element of the Col alpha2(XI)

geneR

ela

tive

lu

cife

rase

act

ivit

y

Cells

Stem cells

Selection bysurface antigensand cis-elements

ProgenitorsTargetingof differentiation

Keio UniversitySchool of MedicineDept of MedicineMakino, ShinjiFukuda, KeiichiKizaki, Masahiro

Dept of PhysiologyOkano, HideyukiShimazaki, TakuyaKohyama, Jun

Saitama Medical CollegeGojo, SatoshiKyo, Shunei

Dept of OrthopedicsToyama, YoshiakiImabayashi, HideakiKensuke, Ochi

Dept of MicrobiologySegawa, Kaoru

NIH, USAKo, Minoru SH

Kumamoto UniversityTaga, TetsuyaNakashima, Kinichi

National Cancer Center, JpnKiyono, Tohru

Helix InstituteIsogai, TakaoSugiyama, TomoyasuIrie, Ryotaro　

National Center for Child Health and Development

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