Biomimetic Materials for Engineering Stem Cells and Tissues - Biomimetics: Advancing Nanobiomaterials and Tissue Engineering - page 324

could be used clinically. For example, only a very few tissue engineered prod-
ucts are clinically available since the evolution of tissue engineering. Advances
in the development of biomaterials and technology have led to the introduction
of new concepts, biomimetics for instance, in tissue engineering approaches in
recent days. Biomimetically-developed materials (also called biomimetic materi-
als) could mimic the features of the native extracellular matrix (ECM) suitable for
tissue culture, resulting in better cell-material interaction, cell-cell communication
and specifi c tissue organization. Such biomimetic materials can also be used to
manipulate the stem cells to control or regulate the cellular functions depending
on the needs of the tissue to be engineered. Keeping these points in mind, the main
focus of this chapter is to introduce the concept of biomimetic engineering of scaf-
folds to manipulate stem cells for their use in tissue engineering. The methods of
fabrication of biomimetic materials and the surface modifi cation of these materials
for better cellular recognition are also discussed.
Keywords: Biomimetic, scaffold, microenvironment, stem cell, tissue engineering
14.1 Introduction
Tissue engineering is an interdisciplinary fi eld of biomedical applied
research that involves the combined use of cells and scaffolds, made of bio-
materials, to aid in the regeneration of tissues which lack self-regenerating
ability, and in the repair of tissues that are severely injured or damaged [1].
The scaffold, by defi nition, is a temporary supporting structure that helps
grow cells and tissues under the laboratory conditions. It is also called syn-
thetic extracellular matrix (ECM) as it plays a key role in supporting the cells
to accommodate them. These cells then undergo proliferation, migration,
and differentiation in three dimensions in a defi ned microenvironment,
which eventually leads to the formation of a specifi c tissue with appropriate
physiological functions as found in the host tissue. The objective of scaffold
design is to create a structure that could mimic the native ECM until cells
seeded onto the scaffold and/or those cells derived from the host tissue
can synthesize its own matrix proteins. The general properties necessary
for the synthetic scaffold include biocompatibility, biodegradability, bioin-
teractiveness and processability. The scaffold should also possess some spe-
cifi c properties depending on the tissue microenvironment it is designed
to repair and regenerate. The tissue microenvironment is comprised of a
complex mixture of ECM molecules, soluble factors, nonsoluble factors, and
other cell types. It is known that the microenvironment of cells is critical for
maintaining their normal function. Modulating the cellular microenviron-
ment to regulate cell behavior such as the cell-material interaction is there-
fore of great importance to enable a defi ned biological activity.
Extensive research has been directed towards the development of ideal
tissue grafts for many tissues such as skin, cartilage, bone, blood vessel,