Biomimetic ECM Scaffolds Prepared from Cultured Cells - Biomimetics: Advancing Nanobiomaterials and Tissue Engineering - page 246

constructs. These results indicate that the engineered tissues exhibit a car-
tilage-specifi c ECM composition.
The expression levels of the genes encoding collagen II ( COL2A1 ),
aggrecan ( ACAN ) and SOX 9 ( SOX9 ) are examined by real-time PCR. The
expression levels of these genes are up-regulated when MSCs are cultured
in ECM-M and ECM-C in comparison to pellet-cultured MSC. The gene
expression levels increase with the culture period. The gene expression
results, together with the histological and immunohistochemical stain-
ing results, indicate that cartilage-like tissue is engineered when MSC
are cultured in the ECM-M and ECM-C scaffolds. ECM-M and ECM-C
scaffolds promote chondrogenic differentiation of MSCs. However, the
effects of ECM-M and ECM-C on MSCs chondrogenesis are not identical.
ECM-M more effectively promotes chondrogenic gene expression relative
to ECM-C.
The ECM-F scaffold is used for three-dimensional culture of fi broblasts
to regenerate dermal tissue. Human dermal fi broblasts are seeded and
cultured in ECM-F. Fibroblasts adhere in ECM-F after a 30 min culture
period. The cells distribute into the pores and on the surfaces of the ECM
scaffolds. The cell seeding effi ciency of fi broblasts in ECM-F is 84.7 ± 8.1%.
The ECM molecules in the scaffolds function as adhesion-promoting fac-
tors to support cell adhesion. The cells spread on the scaffolds after 3 h of
culture. The cells proliferate and produce ECM to cover all of the openings
and distribute homogenously after a 4-day culture period.
The viability of the fi broblasts cultured in ECM-F for 12 h, 24 h and
2 weeks is evaluated by calcein-AM/PI double staining. Most of the cells
are stained by calcein-AM, and almost no dead cells are detected. And
the cells show a typical spindle fi broblastic morphology. These results
indicate a high viability of the fi broblasts cultured in the ECM scaffolds.
After culture for 2 weeks, the pores in ECM-F are completely fi lled with
ECM and fi broblasts. HE staining of the cultured fi broblast/ECM scaffold
implants after 2 weeks of culture indicates that the fi broblasts are distrib-
uted throughout the scaffold and form a uniform layer of dermal tissue
approximately 150 μm thick. The ECM-F scaffold promote regeneration
of dermal tissue.
10.5 Summary
Biomimetic ECM scaffolds can be prepared not only from decellularized
tissue and organs, but also from cultured cells. By using a selectively
removable template, ECM scaffolds from any cell types can be obtained.
The compositions and functions of cultured cell-derived ECM scaffolds
are dependent on the type and phenotype of cells used for the prepara-
tion of scaffolds. The ECM scaffolds support cell adhesion, proliferation