Biomedical Engineering Reference
In-Depth Information
Fig. 6
(
a
) Random orientation of cells grown in a gel without scaffolding capability (control gel,
left
) and their patterned orientation when grown in a scaffolded gel (
right
). (
b
) Confocal fl uores-
cence microscopy
z
-sections (1 mm apart) though a portion of a control (
top
) and scaffolded
(
bottom
) gel
Success with controlling the organization of individual cells within a three-
dimensional population could lead to the engineering of superstructures of cells that
more closely resemble those of the human body. The PDMS/collagen gel composite
technique we have employed, however, can allow for complex three-dimensional
patterns to be created for engineering virtually any tissue where organization of the
cells relative to each other is important.
Another very active area of three-dimensional tissue engineering research is in
the development of a tissue-engineered, small-diameter (<6 mm) vascular graft.
One of the most diffi cult aspects of the vasculature to recreate in biological con-
structs has been the strength of native vessels to withstand the physiological pres-
sures. The medial layer of blood vessel is composed of multiple layers of smooth
muscle cells arranged in alternating spiral layers (Rhodin
1980
) . The organization
of ECM proteins, such as collagen and fi bronectin and elastin, also play an impor-
tant role in vessel strength and integrity. The medial layer provides the strength,
elasticity and contractility to the vessel. The patterning of the medial layer is one
aspect that has never been investigated in artifi cial constructs. It is believed that this
distinct architecture plays a role in the function of the medial layer of the vessel.
