fibroin
noun
fi·bro·in
ˈfī-brə-wən 
ˈfi-,
-brō-ən
: an insoluble protein comprising the filaments of the raw silk fiber
Examples of fibroin in a Sentence
Recent Examples on the Web
Using advanced transgenesis techniques, scientists spliced multiple spider silk genes into the insect’s genome, prompting its silk glands to produce spider silk proteins alongside their native fibroin.
—
New Atlas, 31 Aug. 2025
In much the same way that silk cocoons unravel, silk unravels, too, when rid of its sericin and transformed into an aqueous solution of pure fibroin fiber.
—Amy Paturel, Discover Magazine, 22 Apr. 2025
The team boiled silk moth cocoons in a solution to break them down into proteins called fibroin.
—Ars Technica, 30 Dec. 2024
The formula is powered by zinc oxide, two silk proteins (sericin and fibroin), niacinamide, squalane, and hyaluronic acid to protect, moisturize, and prep skin for makeup.
—Annie Blackman, Allure, 2 Dec. 2024
Rafael Martin/Europa Press/Abaca/Sipa USA/AP Their team mixed lavender oil into a warm solution of fibroin, a flexible protein made by silkworms, and gum arabic, a substance from acacia trees that helps stabilize materials.
—Erika Page, The Christian Science Monitor, 4 Nov. 2024
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New Atlas, 31 Aug. 2025
In much the same way that silk cocoons unravel, silk unravels, too, when rid of its sericin and transformed into an aqueous solution of pure fibroin fiber.
—Amy Paturel, Discover Magazine, 22 Apr. 2025
The team boiled silk moth cocoons in a solution to break them down into proteins called fibroin.
—Ars Technica, 30 Dec. 2024
The formula is powered by zinc oxide, two silk proteins (sericin and fibroin), niacinamide, squalane, and hyaluronic acid to protect, moisturize, and prep skin for makeup.
—Annie Blackman, Allure, 2 Dec. 2024
Rafael Martin/Europa Press/Abaca/Sipa USA/AP Their team mixed lavender oil into a warm solution of fibroin, a flexible protein made by silkworms, and gum arabic, a substance from acacia trees that helps stabilize materials.
—Erika Page, The Christian Science Monitor, 4 Nov. 2024
Cite this Entry
“Fibroin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fibroin. Accessed 3 Feb. 2026.
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