Introduction - Microsurgery: Advances, Simulations, and Applications - page 24

from a multipotent ES cell. Therefore, if somatic stem cells destined
to form a tissue or further differentiated cells are implanted to
damaged part of a tissue, the damaged part will be restored. In this
kind of cell implantation-based regenerative medicine, technological
development of cell separation, differentiation, and growth are very
important.

Cell implantation
(Inject stem cells or progenitor cells to a regeneration part)

Regenerative Medicine

Tissue Engineering
(Reconstruct a large tissue or an organ in vitro by using cells)

Figure 1.24 Approaches for regenerative medicine.

Inner Cell Mass
(ICM)

Cluster formation
of ES cells

Fertile egg Cleavage Culture

Figure 1.25 Process for obtaining embryonic stem cells from a fertile egg.

Multipotent stem cell (ES, EG)

Germ cell Tissue stem cell

Hematopoietic
Stem cell

Mesenchymal
Stem cell

Liver

Nerve Epithelium

Progenitor cell

Fibroblast Chondrocyte Endothelial

cell

Cardiomyocyte Osteoblast

Cornea,
Corium

Cartilage Endothelium Myocardium Bone

Figure 1.26 Differentiation from a multi-potent stem cell.

The other approach is tissue engineering. Tissue engineering
means a technology to regenerate a damaged tissue whose deicit is
too heavy to be cured by only cell implantation. The most important
issue in tissue engineering is the development of appropriate
environment for in vivo -like regeneration. In this section, traditional
artiicial organs, cell implantation-based ( in vivo ) regeneration and