Multicomponent
fibers obtained from multiple polyelectrolyte interfaces
Fused polymer-based
multi-component fibers provide well-defined domains for cell co-culture in
tissue engineering
Polymer fibers play a central role in the production of
biomaterials for tissue engineering applications. Generated from
self-assembling polyelectrolytes, these materials provide matrices for cells to
grow and differentiate. Unfortunately, polymer fibers cannot encapsulate
different cell types in a spatially defined manner for culture, thereby
hindering their implementation in native tissue mimics.
To overcome these limitations, Andrew Wan and Jackie Y.
Ying at the A*STAR Institute of Bioengineering and Nanotechnology and
co-workers have developed a method that fuses several fibers from multiple
polyelectrolyte interfaces. This method creates matrices composed of
well-defined, spatially patterned domains at the micrometer scale, facilitating
cell co-culture within the same fiber1.
Ying explains that polyelectrolyte-based fibers have
previously yielded three-dimensional scaffolds for cells, inspiring the team to
fuse these materials to achieve co-culture.
The team’s goal is to exploit the patterning ability of
their method to give structures that emulate native tissues such as the liver.
“Many cell types are involved in the liver, and they are spatially patterned
with respect to each other to achieve liver function,” adds Wan.
Unlike typical techniques deployed to manufacture
multi-component fibers, the interfacial polyelectrolyte complexation adopted by
Wan and Ying’s team is a gentle, water-based chemical process. “When two
oppositely charged polyelectrolytes come into contact with each other, a
complex forms at their interface,” explains Wan. “Upward drawing of this
complex leads to the formation of a fiber.”
The researchers flanked a droplet of polyelectrolyte
solution with two droplets of the oppositely charged polyelectrolyte, creating
two interfaces from which two fibers were drawn and fused. Upon contact, the
wet fibers zipped together, forming a Y-shape pattern over the droplets and
producing a two-component fiber. By increasing the number of interfaces to
three and four, the team obtained three- and four-component fibers.
Assessments of the ability of the fibers to enable
co-culture in distinct domains showed that bone-forming cells encased in the
outer layers of four-component fibers exclusively propagated and accumulated in
those layers. Further experiments were carried out on fibers that consisted of
a central core containing endothelial cells surrounded by outer layers filled
with liver cells. The liver cells closely aggregated along the fiber without
spreading to the core, where the endothelial cells had formed blood vessel-like
structures.
The researchers are currently investigating ways to
design better mimics of native tissue using their process. They are also
planning on using the multi-component fibers to study the influence of cellular
microenvironment on cancer cell behavior.
The A*STAR-affiliated researchers contributing to this
research are from the Institute of
Bioengineering and Nanotechnology
References
- Wan,
A. C. A., Leong, M. F., Toh, J. K. C., Zheng, Y. & Ying, J. Y.
Multicomponent fibers by multi-interfacial polyelectrolyte
complexation. Advanced Healthcare Materials 1,
101–105 (2012). | article
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