Biomedical Engineering Reference
In-Depth Information
mechanobiology allowed a better understanding of the fundamental role of
in vitro
mechanical stimuli in maintaining the phenotype of tendinous tissues. This chapter analyzes
the techniques used so far for the
in vitro
regeneration of tendinous tissues.
2. Scaffolds requirements for tendon tissue engineering
The scaffold should encourage cellular recruitment and tissue ingrowth. Early in the repair
process, the scaffold should maintain its mechanical and architectural properties to protect
cells and the new, growing tissue from strong forces and early inflammatory events.
Subsequently, the scaffold should be gradually reabsorbed allowing a controlled exposure
of the regenerating tissue to the local cellular, biochemical and mechanical environment.
This will allow the tissue to develop more naturally and function more efficiently.
In order to avoid stress shielding, the scaffold should ideally degrade at the same rate that
the new tissue is created. In order to ensure final clinical use, neither the scaffold nor its
degradation products should be harmful to the surrounding tissue and they should not
result in unresolved inflammation or other deleterious biological responses.
The tendon tissue engineering aims to repair tendon lesions in situ by integrating
engineered, living substitutes with their native counterparts in vivo (Fig. 2). For this
purpose, scaffolding materials are needed, and these ideally should fulfill the following
requirements (Liu Y et al. 2008):
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Biodegradability with adjustable degradation rate.
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Biocompatibility before, during and after degradation.
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Superior mechanical properties and maintenance of mechanical strength during the
tissue regeneration process.
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Bio-functionality: the ability to support cell proliferation and differentiation, ECM
secretion, and tissue formation.
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Processability: the ability to be processed to form desired constructs of complicated
structures and shapes
Fig. 2. Overview of tissue engineering approaches employing cell-polymer constrcuts.
