Their properties are determined by, structure, assembly and mutual interactions of their molecular constituents. For examples, bone presents a hierarchical composite structure of hydroxyapatite and collagen, whose organisation makes it resistant to multi-axial stresses.
Soft tissues contain actin, elastin, collagens and mucopolysacharides.
Microarchitecture and composition of these components are responsible for the mechanical properties and performance of tissues and organs. The properties of composite materials depend on the properties of their constituent molecules, their distribution, and interaction, and must have anisotropy and viscoelastic properties of natural tissue. Based on the structure and performance of living tissues it is possible to design biomaterials with properties suitable for specific applications such as joint, ligament, tendon, inter vertebral discs, and biological fluids substitutes or scaffolds for living cells colonization and tissue engineering .