Spider Silk-production and Biomedical Applications

Abstract

Spider silk is Nature's high performance fiber with an unprecedented ability to absorb energy, due to a combination of strength and extensibility. Also, spider silk has been ascribed abilities to stop bleedings and promote wound healing (Bon, 1710-1712; Newman and Newman, 1995). These traits have made spider silk an attractive material for biomedical applications. While the outstanding mechanical properties of spider silk have been well documented (see e.g., Gosline et al., 1999; Hu et al., 2006), the suggested utility of spider silk has been hampered by lack of large scale production. Spiders are territorial and produce low amounts of silk and can therefore not be employed as such for industrial silk production. An alternative then is recombinant expression of spider silk proteins (spidroins), or designed proteins with sequences inspired by the overall properties of spidroins. The nature of spidroins (i.e. they are large, repetitive, and aggregation prone) pose significant challenges to their production. Several quite different production strategies have been described, the most common being prokaryote expression systems (e.g., Echerichia coli) and processes that involve use of precipitation and resolubilization procedures, cf below and (Rising et al.) potential applications of recombinant spider silk include implants to restore the function of damaged tissue (e.g., tendon repair) as well as matrices for cell culture and tissue engineering. In line with this, some recombinant spider silks have been used in cell culture studies and also there are a few reports on the in vivo tolerance of this material.