Liquid crystals in biology I. Historical, biological and medical aspects

Stewart, Gordon T.

doi:10.1080/0267829031000097457

“…The pre-requisite to understand biomolecular function in the context of life and metabolism, it is necessary to analyze interactions of biomolecules by each other. A promising approach to study these interactions is to use liquid crystalline (LC) materials since it is advantageous as many biological systems, including cell membranes, phospholipids, cholesterols, DNA and so forth, exist in LC phases (Stewart, 2003; Steward, 2004). Recently, LCs have been explored for the design of interfaces that mediate desired interactions with biological systems (Lowe and Abbott, 2012).…”

Section: Introductionmentioning

confidence: 99%

Liquid Crystal Biosensors: New Approaches

Sidiq¹

2016

Proceedings of the Indian National Science Academy

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This review describes recent advances in the area of research involving the interfacial design of liquid crystal (LC) based biosensors. The first advance revolves around the design and modulation of LC based interfaces for developing LC based stimuli responsive materials. For example, designing nanostructured thin films of LC-based colloidal gels exhibit the sensitivity and specificity with the added benefits of mechanical robustness and processability and can be used to report adsorption of biological and synthetic amphiphiles at aqueous-LC interfaces. In addition, a new pathway for the easy formation of spontaneous uniform LC droplets has been reported that provides a high spatial resolution of micrometers with a very high sensitivity. A second development has focused on the investigations of the ordering of LCs at aqueous interfaces for qualitative and quantitative understanding of important biomolecular interactions for bedside diagnostics and laboratory applications. These important biomolecular interactions include: (i) protein endotoxin interactions as these lead to divergent effects on lipopolysaccharide (LPS)-induced responses, (ii) pH induced conformation change of cardiolipin (CL) which is known to affect a range of cellular processes and (iii) endotoxin interactions with bacterial cell wall components.Thirdly this study involves design of LC based sensors that hold promise to act as a marker for cells and cell based interactions. Overall, this review illustrates new approaches for developing LC based stimuli responsive materials that are anticipated with fundamental understanding of biomolecular interactions and provide a gateway for further advances involving LCs. Keywords IntroductionBiomolecular interactions govern the affinity and specificity of complex formation and determine their biological function which could be of enormous scientific and practical importance. The pre-requisite to understand biomolecular function in the context of life and metabolism, it is necessary to analyze interactions of biomolecules by each other. A promising approach to study these interactions is to use liquid crystalline (LC) materials since it is advantageous as many biological systems, including cell membranes, phospholipids, cholesterols, DNA and so forth, exist in LC phases (Stewart, 2003; Steward, 2004). Recently, LCs have been explored for the design of interfaces that mediate desired interactions with biological systems (Lowe and Abbott, 2012). LC materials allow label-free observations of biological phenomena as the orientational properties of LCs enable the amplification and the transduction of biologically relevant binding events at nanostructured surfaces into optical outputs visible by naked eye (Brake et al., 2003a; Lin et al., 2011;Brake and Abbott, 2002; Brake et al., 2003b; Lockwood et al., 2005; Price and Schwartz, 2008;Brake et al., 2005; Lockwood et al., 2006;Sivakumar et al., 2009;Gupta et al., 2009; Park and Abbott, 2008; Hu and Jang, 2012;Bai et al., 2014; Khan and Park, 2014;Sadati et al....

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“…in a variety of ways, ranging from variation of temperature, stress, and electrical field, to variation of dopant concentration [56][57][58][59][60]. • Biomedical Applications -this is an emergent field for the use of liquid crystal devices for noninvasive biomedical imaging applications; this could include frequency domain optical tomography (FD-OCT), fluorescence imaging, aberration correction phase masks, birefringent filters, and polarographic imaging [61][62][63].…”

Section: Applications Of Chiral Nematic Phasesmentioning

confidence: 99%

“…The key step in synthesis of 57 or 58 is a copper catalyzed 1,3-dipolar cycloaddition of the azide (60) to alkyne (61) to give the [1-3]triazole (62) (Scheme 14.5). The azide (60) was prepared from (S)-2-methyl-1-butanol (9) via its mesylate (59) using sodium azide in DMF.…”

Section: Ester Mesogensmentioning

confidence: 99%

Design and Synthesis of Chiral Nematic Liquid Crystals

Taugerbeck

¹

,

Booth

²

2014

Handbook of Liquid Crystals

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The article contains sections titled: Introduction to the Chiral Nematic Phase and Its Properties Formulation and Application of Chiral Nematic Liquid Crystal Mixtures Applications of Chiral Nematic Phases Classification of Chiral Nematic Liquid‐Crystalline Compounds Aspects of Molecular Symmetry for Chiral Nematic Phases Type I Chiral Nematic Liquid Crystals Azobenzenes and Related Mesogens Azomethine ( S chiff's Base) Mesogens Stable Phenyl, Biphenyl, Terphenyl, and Phenylethylbiphenyl Mesogens Ester Mesogens Derivatives of Chiral Alcohols Type II Chiral Nematic Liquid Crystals Type IIa Twin Systems Using Chiral Flexible Spacers Type IIb Materials Using Achiral Flexible Spacers and Chiral Terminal Groups Type IIc and d Materials Using One or Two Chiral Cores Type III Chiral Nematic Liquid Crystals Cholesteryl Esters Chiral Mesogens Derived from Cyclohexane Chiral Heterocyclic Mesogens Axially Chiral Liquid Crystals Axially Chiral Alkenes and Overcrowded Alkenes Allenes Tricyclo[4.4.0.0 3,8 ]decane or Twistane Derived Mesogens Sterically Hindered Biphenyl Derivatives Spirobiindane Derivatives Concluding Remarks

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“…In general, interfacial interactions between LCs and bio-samples (or sensing targets) are the key to design a biosensor using nematic LCs [2][3][4][5][6][7]. Such an interfacial interaction often causes the re-orientations of LC molecules at the interface.…”

Section: Biosensors Using Nematic Liquid Crystalsmentioning

confidence: 99%

Liquid Crystals for Bio-medical Applications

Lin

¹

2014

Topics in Applied Physics

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Thermotropic nematic LCs can modulate light in phases, amplitudes, and polarizations [1]. Many photonic applications based LCs have developed, such as displays, electro-optical switches, lenses, optical vortex generators, variable optical attenuations, solar cells and so on. Thermotropic nematic LCs have great potential in bio-medical applications. In this session, we mainly introduce two the bio-medical applications based on thermotropic nematic LCs: biosensors and ophthalmic lenses. In biosensors, the key is interfacial interactions between biosamples and LC molecules. We will introduce a LC and polymer complex system, the LC and polymer composite film (LCPCF), whose surface free energy is electrically switchable. LCPCF can help to test the sperm quality and high-density-lipoprotein (HDL). In ophthalmic applications, we will introduce the challenges and requirements for design of ophthalmic lenses. A polarizer-free LC lens with large aperture size is also introduced. Biosensors Using Nematic Liquid CrystalsIn general, interfacial interactions between LCs and bio-samples (or sensing targets) are the key to design a biosensor using nematic LCs [2][3][4][5][6][7]. Such an interfacial interaction often causes the re-orientations of LC molecules at the interface. As a result, optical properties of LC change and the change of the orientation of LC can be read out by observing under a polarizing microscopy. LC can optically amplify the biological binding events and help us to study the biology. The main approach is to immobilize thermotropic nematic LC onto a solid surface as a sensing interface for bio-samples. 5CB is a commonly used a LC material for biosensing. In the literatures, 5CB has been proved for sensing many bio-samples,

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Liquid crystals in biology I. Historical, biological and medical aspects

Cited by 63 publications

References 45 publications

Liquid Crystal Biosensors: New Approaches

Liquid Crystal Biosensors: New Approaches

Design and Synthesis of Chiral Nematic Liquid Crystals

Liquid Crystals for Bio-medical Applications

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