Page 19 - Tailoring Electrospinning Techniques for Regenerative Medicine - Marc Simonet

functions like morphogenesis, di erentiation, proliferation, adhesion and migration.
When aiming for the most natural template, decellularized ECMs would thus be the obvious sca old choice. Assuming an optimal decellularization process, these sca olds can o er all required cell adhesion ligands at the appropriate locations, while retaining the native architecture and its mechanics. Unfortunately, homogra s that can be decellularized for this purpose are only scarcely available, whereas xenogra s can cause severe immunogenic responses and su er from the risk of zoonoses.4,5
Therefore, man-made sca olds are a promising alternative. Sca olds made of natural and synthetic materials can be tailored to fit many demands. The sca old shape can be matched to the patients´ demands and fiber morphologies adapted to meet specific cell requirements. Material and sca old design choices allow to adjust sca old biocompatibility, degradation rate and mechanical properties. Additionally, selective ECM, bioactive and bioresponsive molecules can be incorporated into the sca old and might help to control and direct cell recruitment and subsequent tissue formation.
1.1 Sca old demands for tissue 1 engineering
The design and production of 3D sca olds with both microscopically and macroscopically optimized material properties is critical to succeed in engineering a living tissue analog. The demands on a sca old are manifold and vary depending on the chosen tissue engineering approach and tissue to be replaced.6–10 In general, the biocompatible sca old should be a structural blueprint and mimic the mechanical behavior of the targeted tissue. In addition, it needs to facilitate nutrition exchange and allow and guide cell infiltration and tissue formation throughout the entire sca old. If this requires a layered or heterogeneous tissue, all these demands should be spatially controlled along the sca old and adaptable over a certain time period. Control of properties over time is essential in a degradable sca old which will eventually be completely replaced by living tissue. In that case the functional loss due to degradation has to be compensated by an in-time tissue regeneration. Table 1.1 shows sca old demands with sca old characteristics influencing the corresponding demand. Having control of or at least the capability to adjust theses sca old characteristics is crucial in order to create an optimized sca old mimicking the ECM.
GENERAL INTRODUCTION
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