Living Biomaterials

Living biomaterials are the result of a combination of live organisms such as bacteria or cells with traditional biomaterials. This integration yields a unique system that enjoys the best of both worlds: a live manufacturer that can sense its environment, produce, and release biomolecules while exhibiting excellent stability in harsh physiological milieus. Such biomaterials can be natural, synthetic, or semi-synthetic as long as they retain their main pre-requisite characteristics of biodegradability and biocompatibility with body tissues. The integration of functional microorganisms into polymeric matrices imposes stringent requirements on material composition and engineering. The matrix must support growth and reproduction of the encapsulated organisms, while allowing the absorption and release of chemicals and biological molecules. The living component can be either natural (wild type) or genetically modified, each with its own advantages and disadvantages. For example, wild-type organisms are easier to produce and generally produce ecofriendly materials. On the other hand, thanks to remarkable advances in synthetic biology, genetically modified organisms can be reprogrammed to produce and secret desired biomolecules or to exhibit specific functionalities, but at the same time they elicit some inherent concerns regarding unintended ecological and health-related consequences. In this chapter, we introduce the concept of living biomaterials, explore various systems, and focus on the interactions and complexity of these multi-component systems. Then, we review some applications of living biomaterials with emphasis on the medical field. Finally, we present two case studies, in which we delve into the details of specific systems in an attempt to illustrate this fascinating topic.