Biodegradable polymer which, edible films have gained more attention due to their environmentally-friendly characteristics, vast variety and availability, non-toxicity, and low cost. Biodegradable polymers have a long history, and since many are natural products, the precise timeline of their discovery and use cannot be accurately traced. One of the first medicinal uses of a biodegradable polymer was the catgut suture, which dates back to at least 100 AD. The first catgut sutures were made from the intestines of sheep, but modern catgut sutures are made from purified collagen extracted from the small intestines of cattle, sheep, or goats. The concept of synthetic
Ukulele of an old wooden cigar box. These instruments usually have four strings; some strings may be paired in courses, giving the instrument a total of six or eight strings (primarily for greater strumming volume.) The strings themselves were originally made of catgut. Modern ukuleles use nylon polymer strings, with many variations in the material, such as fluorocarbon, aluminium (as winding on lower pitched strings), and Nylgut. Instruments with 6 or 8 strings in four courses are often called taropatches, or taropatch ukuleles. They were once common in a concert size, but now the tenor size is more common for six-string