Method for the Destruction of Endotoxin in Synthetic Spider Silk Proteins

Journal Article · 14 August 2018 · Scientific Reports

DOI: https://doi.org/10.1038/s41598-018-29719-6 · OSTI ID:1500013

Decker, Richard E. ^[1]; Harris, Thomas I. ^[2]; Memmott, Dylan R. ^[2]; Peterson, Christopher J. ^[2]; Lewis, Randolph V.  ^[2]; Jones, Justin A. ^[2]

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1. Utah State Univ., Logan, UT (United States); OSTI
2. Utah State Univ., Logan, UT (United States)

Although synthetic spider silk has impressive potential as a biomaterial, endotoxin contamination of the spider silk proteins is a concern, regardless of the production method. The purpose of this research was to establish a standardized method to either remove or destroy the endotoxins present in synthetic spider silk proteins, such that the endotoxin level was consistently equal to or less than 0.25 EU/mL, the FDA limit for similar implant materials. Although dry heat is generally the preferred method for endotoxin destruction, heating the silk proteins to the necessary temperatures led to compromised mechanical properties in the resultant materials. In light of this, other endotoxin destruction methods were investigated, including caustic rinses and autoclaving. It was found that autoclaving synthetic spider silk protein dopes three times in a row consistently decreased the endotoxin level 10–20 fold, achieving levels at or below the desired level of 0.25 EU/mL. Products made from triple autoclaved silk dopes maintained mechanical properties comparable to products from untreated dopes while still maintaining low endotoxin levels. Triple autoclaving is an effective and scalable method for preparing synthetic spider silk proteins with endotoxin levels sufficiently low for use as biomaterials without compromising the mechanical properties of the materials.

• Research Organization: Utah State Univ., Logan, UT (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: EE0006857
• OSTI ID: 1500013
• Journal Information: Scientific Reports, Journal Name: Scientific Reports Journal Issue: 1 Vol. 8; ISSN 2045-2322
• Publisher: Nature Publishing GroupCopyright Statement
• Country of Publication: United States
• Language: English