Photocrosslinkable Materials for the Fabrication of Tissue-Engineered Constructs by Stereolithography - Tissue Engineering: Computer Modeling, Biofabrication and Cell Behavior - page 147

Ta b l e 1 Biological, physical and mechanical requirements of scaffolds [ 1 , 8 , 14 , 15 ]
Biological requisites

Biocompatibility Scaffold must be non-toxic and interact with biological

tissues without inducing adverse responses

Biodegradability Scaffold material should be gradually degraded in

non-toxic products with appropriated molecular weights
to allow the clearance from the human body

Degradation rate The degradation rate should be adjustable and match the

regeneration rate of the new tissue

Porosity Scaffold must exhibit adequate pore size and

interconnected pores. These properties are fundamental
to promote an efficient cell seeding, nutrient and waste
exchange, vascularization and tissue in-growth

Bioactivity Scaffolds should be able to stimulate the attachment,

proliferation and differentiation of the seeded cells,
guiding the growth of the new tissue. The constructs
should also be able to incorporate and deliver drugs and
growth factors according to specific release profiles

Mechanical and physical requisites

Mechanical strength Scaffolds must present adequate strength and stiffness

to support stresses in the host tissue environment.
Mechanical properties should be similar to those in the
native tissue, providing a temporary support to the
tissue formation. During regeneration, scaffolds
gradually transfer the mechanical loads and stresses to
the new tissue

Surface finish The surface chemistry of scaffolds should promote an

optimal biomechanical coupling between the scaffold
and the tissue, promoting cell attachment,
differentiation and proliferation

Sterilization Scaffolds must be easily sterilized using thermal,

chemical or radiation processes, without degradation or
modification of the material properties

of 3D biocompatible scaffolds and the manipulation of living cells and signalling
molecules (e.g. growth factors), as well the in vitro culture of the cellular tissue-
engineered constructs within bioreactors to promote the growing of clinically rel-
evant healthy tissues. Scaffolds, from either natural or synthetic materials, play an
important role on tissue regeneration, mimicking the function of the natural EMC of
the human body. These structures act as a temporary support for the seeded autol-
ogous or allogeneic cells proliferation, differentiation, and synthesizing their own
ECM [ 14 , 15 , 69 ]. Scaffolds need to successfully satisfy several requirements, as
indicated in Table 1 .