Hydrodynamics in Porous Media with Applications to Tissue Engineering - Porous Media: Applications in Biological Systems and Biotechnology - page 92

Porites species

Bioglass ®

Actopora species

Foamy and fibrous structures

FIGURE 3.5
Various scaffolding porous materials and structures, either natural or artifi-
cial, used in osteoarticular tissue engineering. (Courtesy of D. Hutmacher, H.
Petite, and X. Wang.)

biomaterial as substratum. In such a case the nature of the constitutive bioma-
terials and the local architecture of the substrate are fundamental parameters
for the culture's success. The ideal biomaterials or scaffold must be steril-
izable, biocompatible (noncytotoxic and at least biotolerated), and ideally
bioresorbable (at mid or long term). The scaffold must also be a physical
substratum giving the opportunity to the cells to bind with its surface, to
proliferate, to differentiate, and to synthesize ECM. Moreover, its mechanical
properties have to be as close as possible to those of the natural organ. This
last function is especially important when the implant must have a holding
function after implantation (bony or cartilaginous implants for example).
In the framework of bone and cartilage tissue engineering, various bioma-
terials have been used. Examples are illustrated in Figure 3.5 and some of their
physicochemical properties are given in Table 3.1. Even if metallic porous scaf-
folds have been utilized (titanium [van den Dolder et al . 2003], tantalum and
nitinol [Maurin et al . 2005]), the majority of three-dimensional cell cultures
have been achieved using polymeric or ceramic scaffolds. Among the poly-
meric biomaterials (for a review see [Jagur-Grodzinski 2006]) the most popu-
lar are nonexhaustively the following: the polylactic acid or polylactide (PLA)
(Saini and Wick 2003), the polyglycolic acid (PGA) (Obradovic et al . 2000;
Wilson et al . 2002), polylactic-co glycolic-acid (PLAGA) (Botchwey et al .
2001, 2003, 2004), hyaluronic acid (HA) (Raimondi et al . 2002), or polycapro-
lactone (PCL) (Hutmacher et al . 2001). Scaffolds made of hydrogel can also