Biomaterials of natural origin in regenerative medicine

Abstract

Biodegradable polymers have been used for various applications where the short-lived existence of materials is required and they find applications as sutures, scaffolds for tissue regeneration, tissue adhesives, and transient barriers for tissue adhesion, as well as drug delivery systems. This chapter deals with the most commonly used natural polymers for regenerative medicine. It also presents some examples of commercially available natural-origin materials. Natural polymers are widely used due to their similarities with the extracellular matrix (ECM), the variety of physico-chemical properties, the generally high biological performance and the cell or enzyme-controlled degrad-ability. These characteristics classify the natural-origin polymers as one of the most attractive materials to be used in the tissue engineering field and drug delivery application. The fields of tissue engineering and regenerative medicine aim to promote the regeneration of tissues or replacing failing or malfunctioning organs, by means of combining a scaffold/support material, adequate cells and bioactive molecules. Different materials have been proposed to be used as both three-dimensional porous scaffolds and hydrogel matrices for distinct tissue engineering strategies. Among them, polymers of natural origin are one of the most attractive options. In the following pages, the most studied, promising and recently proposed naturally derived polymers for tissue engineering applications are described. Different classes of such type of polymers and their blends with other polymers are emphasized, with special focus on polysaccharides and proteins. The adaptation of conventional methods or non-conventional processing techniques for processing scaffolds from natural origin based polymers is described. The use of particles, membranes and injectable systems based on this kind of materials is also overviewed, especially for what concerns the present status of the research that should lead towards their final application. Finally, the biological performance of tissue engineering constructs based on natural-based polymers is discussed chronologically, using several examples for different clinically relevant application