Spider Silk-production and Biomedical Applications - Natural Polymers, Biopolymers, Biomaterials, and Their Composites, Blends, and IPNs - page 151

be casted into a coherent and flexible film with a mostly smooth surface. A stable 3D
structure with heterogeneous mounds and craters can also be produced by foaming the
4RepCT protein (Figure 1) (Widhe et al., 2010).
If the intended use of the recombinant spidroin involves biomedical applications,
the scaffolds should be sterilized before usage. This has been achieved by using filtra-
tion, ethanol, ethylene oxide or by autoclaving ( Table 1). In some cases, the scaffolds
have been pre-incubated in cell culture medium before cell culture. Whether traces of
the agents used during production still remain in the scaffolds has not been investi-
gated. However, the processes seem to result in scaffolds suitable for cell culture (see
further below).
Figure 1. Scaffolds of recombinant spider silk. Upper row: photograph of a wet fiber (left) and
scanning electron micrograph of a dried fiber (right). Lower row: photograph of a wet foam (left) and
scanning electron micrograph of a dried foam (right). All scaffolds were made from the miniature
spidroin 4RepCT (see Table 1).
spider silk for in vitro applications
Native spider silk has been shown to support the growth of cells in vitro , for example
chondrocytes (Gellynck et al., 2008b), Schwann cells (Allmeling et al., 2006) and