Liquid Crystalline Systems from Nature and Interaction of Living Organisms with Liquid Crystals

Biomaterials, which are substances interacting with biological systems, have been extensively explored to understand living organisms and obtain scientific inspiration (such as biomimetics). However, many aspects of biomaterials have yet to be fully understood. Because liquid crystalline phases are ubiquitously found in biomaterials (e.g., cholesterol, amphiphile, DNA, cellulose, bacteria), therefore, a wide range of research has made attempts to approach unresolved issues with the concept of liquid crystals (LCs). This review presents these studies that address the interactive correlation between biomaterials and LCs. Specifically, intrinsic LC behavior of various biomaterials such as DNA, cellulose nanocrystals, and bacteriaare first introduced. Second, the dynamics of bacteria in LC media are addressed, with focus on how bacteria interact with LCs, and how dynamics of bacteria can be controlled by exploiting the characteristics of LCs. Lastly, how the strong correlation between LCs and biomaterials has been leveraged to design a new class of biosensors with additional functionalities (e.g., self-regulated drug release) that are not available in previous systems is reviewed. Examples addressed in this review convey the message that the intersection between biomaterials and LCs offers deep insights into fundamental understanding of biomaterials, and provides resources for development of transformative technologies.