Biomedical Engineering Reference
In-Depth Information
transplanted directly to failing hearts, the next challenge is to
engineer organ-like tissues, such as tubular or spherical structures,
that are able to function as a pump. In this section, we introduce the
construction of just such functional organ-like tissue-engineered
structures that can function as a cardiac pump with the potential for
circulatory support.
6d.2
Scaffold-Based Cardiac Pumps
Several research groups have begun to fabricate organ-like structures
using cultured cardiomyocytes (Fig. 6d.1).
Evans et al. developed a tubular cardiac tissue by using rat
embryonic cardiac cells with type I collagen. The tube construct
was designed using counter-rotating cones and a polymerization
chamber for making three-dimensionally aligned collagen fibers.
Tube-cultured cardiomyocytes showed a high level of differentiation
that closely resembled in vivo neonatal ventricular myocytes
compared to planar-cultured cells [1].
Yost et al. created corkscrew-patterned collagen tubular scaffolds
that were seeded with neonatal rat cardiac cell suspensions into
both the tube lumen and the outer surface at one-week intervals.
Mechanical testing indicated that stiffness and viscosity significantly
increased in the collagen tubes seeded with cardiac cells [2, 3].
Birla et al. fabricated a cell-based tubular cardiac pressure-
generating construct with biodegradable hydrogels. The construct
was created by culturing neonatal rat cardiac cells within fibrin
gel and then wrapped around a silicon tube and subsequently
demonstrated its contractile function and aligned cell layers. In
particular, the functional performance of the tube produced an inner
pressure of approximately 0.08 mmHg [4].
Lee et al. described a cardiac organoid chamber prepared by
mixing neonatal rat cardiac cells with a mixture of type I collagen
and Matrigel in a round-bottom mold. The chamber construct
demonstrated structural and mechanical properties that functioned
similar to a ventricular pump, where the construct generated an
inner pressure of approximately 2 mmH
O. They also showed the
variation of regional contractile function in myocardial infarction
model in vitro [5].
Yildrim et al. developed a pouch-like heart tissue by mixing
neonatal rat cardiac cells with type I collagen and Matrigel in a
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