Among the natural polymers starch is of interest. It is regenerated from the carbon dioxide and water by photosynthesis in plants. Owing to its complete biodegradability, low cost and renewability, starch is considered as a promising candidate for developing sustainable materials. Blends of starch with synthetic polymers such as poly vinyl alcohol, aliphatic esters are prepared to achieve the desired performance for different applications. In such blends, the starch particles act as a promoter for plastic matrix biodegradation in applications such as drug delivery systems, hydrogels, bone cements and bone replacement or fixation devices. Nanocellulose can be used as a reinforcing filler to prepare composites with solutions of water soluble polymers, as well as with acrylic and other latex to change the viscosity and increase mechanical properties of dry composites. Of great importance has been the addition to biodegradable polymers, permitting both the improvement of thermo mechanical properties and acceleration in the rate of bio degradation.