Spider silk-based sustainable materials

➤ Desirable properties can be achieved

In order to produce spider silk-like fibers with desired characteristics, the inventors first performed a comprehensive analysis of spider silk genes and constructed a database of the physical, mechanical, and biological properties of various spiders’ silk, SILKome (Arakawa et al. 2022). Based on these data, they identified which sequences need to be altered/designed to produce more water-resistant and biodegradable spider silk.

➤ More sustainable production method

Next, the inventors designed a system for sustainable synthesis of spider silk structural proteins using marine purple photosynthetic bacteria. To express the protein of interest, the researchers developed a method of high throughput bacteria transformation increasing the efficiency by 2 orders of magnitude (Miyamoto et al. 2022). This robust molecular tool of protein transduction can induce a unique cellular uptake mechanism for the efficient transport of bioactive proteins into bacteria.

Genetically modified yeast and bacteria fermentation is commonly used for producing spider silk. Unlike these processes, the use of photosynthetic bacterium doesn’t require feeding therefore reducing the cost of spider silk protein synthesis. At Kyoto Universitya4000L demo plant was built to streamline the process.

➤ Novel spinning method

The inventors also developed the first water-based spinning via LLPS process to draw spider silk fibers. By mimicking the native spinning process spiders use to make silk, the researchers managed to produce synthetic silk fibers structurally similar to the natural spider silk (Malay et al. 2020, Fig.1).

Figure 1. Morphology of biomimetic spider silk fibers.(A) A single fiber generated from 0.5 µl starting volume of MaSp2 protein, a primary component of spider silk. (B) SEM images showing morphology of fibers.

Symbiobe is a spin-off from Kyoto University which produces spider silk polymer and collaborates withSpiber, one of the leaders in spider silk production, as part ofJST COI-Next program.

Technology Readiness Level :7

Potential Applications

Clothing materials
Plastic alternatives

Possible Collaboration Mode(s)

• R&D collaboration
• Licensing
• IP Acquisition
• Other

Patent No :WO2011006133

Publications
Arakawa K, Kono N, Malay AD, Tateishi A, Ifuku N, Masunaga H et al. 1000 spider silkomes: Linking sequences to silk physical properties. Sci Adv 2022; 8: eabo6043.
Miyamoto T, Toyooka K, Chuah J-A, Odahara M, Higchi-Takeuchi M, Goto Y et al. A Synthetic Multidomain Peptide That Drives a Macropinocytosis-Like Mechanism for Cytosolic Transport of Exogenous Proteins into Plants. JACS Au 2022; 2: 223–233.
Malay AD, Suzuki T, Katashima T, Kono N, Arakawa K, Numata K. Spider silk self-assembly via modular liquid-liquid phase separation and nanofibrillation. Sci Adv 2020; 6. doi:10.1126/sciadv.abb6030.