Abstract
M. Tech.
Stem cells are regarded as undifferentiated cells that are capable of selfrenewal,
proliferation, production of a great number of differentiated
progeny, and regeneration of tissues (Blau et al., 2001). The therapeutic
potential of multilineage stem cells for tissue engineering (TE) applications
is vast. Two general types of stem cells are potentially useful for this
application: embryonic stem cells (ESCs) and adult (autologous) stem
cells (Zuk et al., 2001). Traditionally, ESCs are isolated from the inner cell
mass (ICM) of blastocysts, however harvesting of these cells results in the
death of the embryo, which has led to ethical, religious and political issues
(Moore, 2007). In contrast, adult stem cells, by virtue of their nature, are
immunocompatible and have no ethical issues associated with their use
(Zuk et al., 2001).
Subcutaneous adipose tissue is an active and highly complex tissue
composed of several different cell types, and is derived from the
mesodermal germ layer and contains a supportive stromal vascular
fraction (SVF) that can be easily isolated. This SVF contains a
heterogeneous mixture of cells including preadipocytes (Raposio et al.,
2007; Schäffler and Büchler, 2007; Jurgens et al., 2008). The
preadipoctyes are considered as the multipotent stem cells termed
adipose derived stem cells (ADSCs) that have similar properties to bone
marrow mesenchymal stem cells (BM-MSCs) (Fraser et al., 2006).
ADSCs are idyllic for cellular therapy applications due to various factors:
they can be harvested, multiplied and handled easily, efficiently and noninvasively,
they have a pluripotential and proliferative capacity comparable
to BM-MSCs, and morbidity to donors is considerably less, requiring only
local anaesthesia and a short wound healing time. Human ADSCs
(hADSCs) can be expanded in an undifferentiated state and have
multipotential differentiation capacity along the classical mesenchymal
lineages of adipogenesis, osteogenesis, chondrogenesis and myogenesis
(de Villiers et al., 2009).