Biomedical Engineering Reference
In-Depth Information
(HA) carbon nanotubes (CNTs) and layered silicates. Polymer/layered
silicate nanocomposites have recently become the focus of academic and
industrial attention (Sinha Ray and Okamoto, 2003b). The introduction of
small quantities of high aspect ratio nano-sized silicate particles can
significantly improve the mechanical and physical properties of the polymer
matrix (Lee et al., 2003). However, many factors - such as the pore
structure, the porosity, the crystallinity and the degradation rate - may alter
the mechanical properties and, thus, the efficiency of a scaffold. As a
consequence, the scaffold fabrication method should allow for the control of
its pore size and shape and should enhance the maintenance of its
mechanical properties and biocompatibility (Ma, 2004; Quirk et al., 2004).
Many techniques have been applied for making porous scaffolds. Among
the most popular are particulate leaching (Mikos et al., 1993), temperature-
induced phase separation (Nam and Park, 1999), phase inversion in the
presence of a liquid non-solvent (Van de Witte et al., 1996), emulsion freeze-
drying (Whang et al., 1995), electrospinning (Bognitzki et al., 2001) and
rapid prototyping (Ma, 2004). On the other hand, foaming of polymers
using supercritical fluids is a versatile method for obtaining a porous
structure (Quirk et al., 2004; Goel and Beckman, 1994).
This chapter intends to highlight synthetic biopolymer-based nanocom-
posites used for producing porous scaffolds in tissue engineering applica-
tions. The chapter reviews current research trends on nanocomposite
materials for tissue engineering, including strategies for the fabrication of
nanocomposite scaffolds with highly porous and interconnected pores. The
results of in-vitro cell culture to analyze the cell-scaffold interaction using
the colonization of mesenchymal stem cells (MSCs) and degradation of the
scaffolds in-vitro are also discussed.
17.2 Tissue engineering applications
Tissue engineering applies methods from materials engineering and life
science to create artificial constructs for the regeneration of new tissue (Ma,
2004; Langer and Vacanti, 1993). Tissue engineering can create biological
substitutes to repair or replace failing organs or tissues. One of the most
promising approaches is to grow cells on scaffolds; such scaffolds are highly
engineered structures that act as temporary support for cells, facilitating the
regeneration of the target tissues without loss of the three-dimensional (3D)
stable structure.
Polymeric scaffolds play a pivotal role in tissue engineering through cell
seeding, proliferation and new tissue formation in three dimensions. These
scaffolds have shown great promise in the research of engineering a variety
of tissues. Pore size, porosity and surface area are widely recognized as
important parameters for a tissue engineering scaffold. Other architectural
