Control and Monitoring of Scaffold Architecture for Tissue Engineering - Biomaterials Fabrication and Processing - page 86

FIGURE 3.11 OCT image of porous chitosan scaffold with microchannels. The micropores ranged from 50
to 100 µm. The microchannel diameter was around 250 µm.

FIGURE 3.12 OCT image of a fi brous chitosan scaffold. The diameter of the fi bers was around 105 µm and

porosity of 95%.

chitosan scaffolds without interfering with the chemical composition of the polymer, which creates
another technique to alter chitosan degradation profi le by physical means in contrast to the usual
chemical manipulation of the deacetylation degree. 148
The microporous chitosan scaffold with microchannels is specifi cally designed for tendon TE. A
tendon has a high degree of organization of the ECM. The ECM, mainly composed of collagen type I,
is organized in a hierarchy of bundles of different sizes, which are uniaxially orientated 151 in a pro-
teoglycans matrix. Such structure endows the tendon its biomechanical function, withstanding high
tensile stress. So, to be functional, tendon TE has to create an environment for the formation of ori-
entated ECM organization. Consequently, parameters affecting both production and organization of
the ECM have to be considered during the generation of scaffolds for tendon TE. Our dual-mode chi-
tosan scaffold fulfi lls such requirements. The micropores improve chemotransport while the micro-
channels are the main sites for the seeding and growth of the tenocytes. The longitudinal geometry
of the channel induced or guided tenocytes to form bundle-like cell-ECM complex. We have been
testing such hypothesis using specifi c internal architecture scaffold as a cue for better engineering.
By culturing these microchannels scaffolds in a perfusion system, tendon cells are mechanically
stimulated by fl uid shear stress in the microchannel improving the rate of collagen production. 152
From this study, it emerges that OCT can become a powerful tool to monitor scaffold archi-
tecture. The advantages of OCT over other modalities are based on several aspects. First, it is a