Cells cultured on 3-D scaffolds
14 April 2011
Researchers at Karlsruhe Institute of Technology (KIT) have
developed three-dimensional structures on which they can culture
Micrometer-sized anchors are constructed within the scaffold to
which cells can adhere. Adhesion is possible to these anchors only,
not to the remaining structure, so for the first time, cell adhesion
and, hence, cell shape are influenced precisely in three dimensions.
Several approaches have been used to cell culture in
three-dimensional environments which are mostly produced from
agarose, collagen fibers or matrigel. They are used to simulate the
flexible three-dimensional reality in which the cells act normally
and, hence, allow for more realistic experiments than those using
cell cultures in “two-dimensional Petri dishes”. All approaches used so far have one common feature: they are
mostly heterogeneous with random pore sizes. They have hardly been
characterized structurally and biochemically.
It was the objective of the group in the DFG Center for
Functional Nanostructures (CFN) at KIT to develop defined
three-dimensional growth substrates for cell culture. They wanted to
make the cells adhere at certain points only rather than randomly. In this
way, parameters, such as the cell shape, cell volume, intercellular
force development, or cellular differentiation could be determined
systematically as a function of the external geometry of the
A cell in the two-component polymer scaffold.
The photo composition is based on a scanning electron microscopy and
laser scanning microscopy. (Image: CFN)
Laser-scanning microscopy (LSM) of the cell in
the two-component polymer scaffold. The cytoskeleton of the cell is
colored green, parts of the two-component polymer scaffold are
colored white, the “cell holds” are colored red. (Image: CFN)
The team used a special polymer scaffold consisting of a
flexible, protein-repellent polymer with small box-shaped anchors
made of a protein-binding material. For scaffold construction, the
scientists used the Direct Laser Writing Method (DLS) developed by
the physicists Professor Martin Wegener and Professor Georg von
Freymann at CFN.
The scaffold consists of 25 µm high pillars that are connected by
thin bars at various heights. In a second lithography step, the
holds were placed exactly in the middle of the bars. With the help
of a solution of adhesion proteins, the proteins only bind to these
small holds. Within two hours, individual cells colonize the
scaffolds and adhere to the given adhesion points only.
The research is an important step towards the general
understanding of how the natural three-dimensional environment in
the tissue influences the behaviour of cells.
Klein F, Richter B, Striebel T, Franz CM, Freymann Gv,
Wegener M, and Bastmeyer M. Two-Component Polymer Scaffolds for
Controlled Three-dimensional Cell Culture. Advanced Materials,
Volume 23, Issue 11, pages 1341–5, March 18, 2011, DOI: