Page 217 - Advances in Textile Biotechnology

198 Advances in textile biotechnology

non-food applications cover the areas of biological science, tissue engineer-
ing, material science, leather and textile processing (Zhu and Tramper,
2008). When the Activa® TGase available from Ajinomoto is used, care
must be taken to consider the artefacts potentially caused by the presence
of large amounts of maltodextrins, alone or together with sodium caseinate
or lactose, in the commercial formulation. If undesired interferences are
expected, these additives must be removed by applying suitable purifi cation
procedures (Lantto et al., 2005a).

Tissue engineering

TGase can facilitate the manufacture of tissue engineering scaffolds with
structural and functional properties able to support healing in vivo. Scaf-
folds derived from collagen or gelatine are most commonly used for mam-
malian cell growth. Enzymatic crosslinking of collagen scaffolds represents
a viable alternative to chemical or physical approaches that may negatively
affect cell growth. Collagen scaffolds treated with tissue or microbial TGases
displayed enhanced cell attachment, spreading and proliferation of human

osteoblasts and human foreskin dermal fibroblasts, and also showed a
greater resistance to cell-mediated endogenous protease degradation (Chau
et al., 2005). Enzymatically crosslinked, composite collagen scaffolds con-
taining hyaluronan, one of the principal extracellular matrix components
of native intervertebral disc tissue, showed the greatest potential for devel-
oping an injectable cell-seeded scaffold for nucleus pulposus treatment in
degenerated intervertebral discs (Halloran et al., 2008). Garcia et al. (2008)
recently reported the development of enzymatic crosslinked collagen-based
scaffolds for the production of dermal precursors with enhanced wound
healing properties. Scaffolds crosslinked with microbial TGase provided an
optimum substrate for cell migration, preventing wound contraction, stim-
ulating epithelialisation and neoangiogenesis without inducing signifi cant
infl ammatory reaction.
Gelatine, a denatured derivative of collagen, is a versatile biomaterial
that can be easily processed into scaffolds. However, one of gelatine draw-
backs in tissue engineering is its solubility in aqueous medium, therefore
gelatine-containing scaffolds for medium-to-long term applications need to
be crosslinked. Enzymatic crosslinking may be a valid alternative to tradi-
tional strategies using potentially toxic chemical agents, such as glutaralde-
hyde. Moreover, the ability to control scaffold degradation in response to

cell growth rates may represent an attractive and unique benefit of the
enzymatically modulated scaffold structure. Increased thermal, mechanical
and proteolytic stability and reduced citotoxicity as compared with chemi-
cally or physically crosslinked scaffolds have been reported (Barbetta et al.,
2006).

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