Biomaterials and mesenchymal stem cells for regenerative medicine.

The reconstruction of hard and soft tissues is a major challenge in regenerative medicine, since diseases or traumas are causing increasing numbers of tissue defects due to the aging of the population. Modern tissue engineering is increasingly using three-dimensional structured biomaterials in combination with stem cells as cell source, since mature cells are often not available in sufficient amounts or quality. Biomaterial scaffolds are developed that not only serve as cell carriers providing mechanical support, but actively influence cellular responses including cell attachment and proliferation. Chemical modifications such as the incorporation of chemotactic factors or cell adhesion molecules are examined for their ability to enhance tissue development successfully. E.g. growth factors have been investigated extensively as substances able to support cell growth, differentiation and angiogenesis. Thus, continuously new patents and studies are published, which are investigating the advantages and disadvantages of different biomaterials or cell types for the regeneration of specific tissues. This review focuses on biomaterials, including natural and synthetic polymers, ceramics and corresponding composites used as scaffold materials to support cell proliferation and differentiation for hard and soft tissues regeneration. In addition, the local delivery of drugs by scaffold biomaterials is discussed.