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
String instrument to the east of Mesopotamia, in Bactria, Gandhara, and Northwest India, and shown in sculpture from the 2nd century BC through the 4th or 5th centuries AD. During the medieval era, instrument development varied from country to country. Middle Eastern rebecs represented breakthroughs in terms of shape and strings, with a half a pear shape using three strings. Early versions of the violin and fiddle, by comparison, emerged in Europe through instruments such as the gittern, a four stringed precursor to the guitar, and basic lutes. These instruments typically used catgut (animal intestine) and other materials, including silk, for their