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
Trembita Musical Instrument Factory 19 instruments were made. These instruments were diatonically tuned with 34 strings, however they did not have sufficient volume and did not allow the player to play in different keys easily. Continual serial manufacture of banduras was set up in 1964. Vasyl Herasymenko developed an acceptable model instrument and also developed a serial process for the mass production of banduras. From 1964-68 some 300 experimental instruments were produced. These instruments became known as the "Lviviankas" . The first models had 58 strings which included 17 bass strings. This particular instrument differed from counterparts made at the Chernihiv Musical Instruments Factory