Natural Biopolymers for Biomedical Applications

This article presents a comprehensive overview of naturally-derived biopolymers relevant to the biomedical field. Their definition, classification, sources and key requirements for biomedical application are given and their main advantages and disadvantages are highlighted and discussed. A brief description of the structures and the important properties of two principal classes of natural biopolymers, namely, polysaccharides and proteins, are presented with special emphasis on their biomedical applications in wound management products, drug delivery systems, and tissue engineering scaffolds. The section on polysaccharide presents a review of the important characteristics and areas of application of selected members of glucan family, seaweed-derived polysaccharides and glycosaminoglycans of nonmammalian and mammalian origin, with special emphasis on chitosan, a unique positively charged nonmammalian glycan. In the section on protein, the properties and biomedical usage of several important structural proteins are reviewed, and there is a focus on collagen, which is widely used component in tissue engineered devices and other biomedical materials. Further details of the origin, type, and structural diversity of collagen are provided and results around the development of different collagen-based tissue engineering platforms are presented. The article concludes by considering future challenges and directions in this rapidly expanding field.