Made from soy protein fiber left from processing soybean. (abckidsinc.com)
Since silk is a natural protein fiber, it contains 18 types of amino acids that are beneficial to the body. (atsunamatsui.com)
But additional research has confirmed that structures resembling blood cells and collagen protein fibers — key elements of connective tissue — were preserved in six of eight fragments. (discovermagazine.com)