Provenance Record

Well-structured Briefing at 764 words (within 300-800 range). The article clearly explains the SAM fiber concept, the three biological protein sequence sources, the recycling mechanism via formic acid, and the broader context of the textile microplastics problem. The 'What We Don't Know' section is commendable — it honestly flags the absence of published tensile strength figures and unresolved commercial scalability questions.

source-0.html.gz (engineering.washu.edu, HTTP 200): Confirmed the following — (1) SAM stands for Silk-Amyloid-Mussel; (2) research published in Advanced Materials; (3) authors: Jingyao Li, Juya Jeon, Kok Zhi Lee, Fuzhong Zhang of McKelvey School of Engineering; (4) announced May 8 2026; (5) Zhang title 'Francis F. Ahmann Professor in the Department of Energy, Environmental & Chemical Engineering'; (6) '12%' fiber recycling statistic; (7) mussel foot proteins control solubility and wet-shrinkage, spider silk and amyloid sequences supply tensile strength; (8) all three direct quotes attributed to Zhang verified verbatim; (9) funding: USDA, NSF, NIH. source-1.html.gz (source.washu.edu, HTTP 200): Independently confirms all the same claims and quotes. source-2 (advanced.onlinelibrary.wiley.com, HTTP 403): Paywalled journal paper — not readable. However, source-0 and source-1 both cite the same DOI and reproduce all relevant findings. No claim in the article requires the paywalled paper as the sole source.

All specific claims trace to cited sources. Three direct quotes verified verbatim against source-0 and source-1: (1) 'We engineered recyclable protein fibers that dissolve in a formic acid solution within seconds, yet remain stable in water and strong after drying' — confirmed in both sources. (2) 'We tune the mussel foot sequences to make SAM fibers recyclable while preventing them from shrinking when they get wet' — confirmed in both sources. (3) 'Recycling the final product multiple rounds can greatly reduce manufacturing costs over time' — confirmed in both sources. The '12 percent' textile recycling figure and the biodegradability claim are both supported by source-0 and source-1. The article correctly notes that number-of-cycles and tensile-strength data were not disclosed in accessible press materials — accurate and editorially appropriate.

High-quality, well-researched Briefing. All claims are sourced, all quotes are verbatim, the article is appropriately scoped for a Briefing category, and the 'What We Don't Know' section demonstrates editorial restraint. APPROVE.