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
Chakhe of bamboo, ivory, bone or wood, graduated between 2 and 3.5 cm in height, which are affixed to the fretboard with wax or glue. Its highest two strings are made of silk yarn, catgut or nylon while the lowest is made of metal. They are tuned C–G–c. The instrument is usually supported by three or five legs. The player—sitting beside the instrument—uses his or her left hand on the fretboard while plucking the string with his right hand with a 5- to 6-cm long, tapered plectrum made from ivory, bone or water buffalo horn, which is tied to the player's