Role of liquid crystals in the lubrication of living joints

Kupchinov, B. I.; Ermakov, S. F.; Rodnenkov, V. G.; BOBRYSHEVA, S. N.; Beloenko, E.D.; Kestelman, V. N.

doi:10.1088/0964-1726/2/1/002

Cited by 22 publications

(17 citation statements)

References 4 publications

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“…Biological liquid crystalline polymers (BLCP) are anisotropic viscoelastic materials formed by polypeptides [1][2][3][4][5][6][7][8][9], polysaccharides [1][2][3][4]10,11] and polynucleotides [1,3,[12][13][14]. BLCPs exhibit long-range orientational order and, in some cases, partial positional order [15].…”

Section: Introductionmentioning

confidence: 99%

Modeling Textural Processes during Self-Assembly of Plant-Based Chiral-Nematic Liquid Crystals

Murugesan

Rey

2010

Polymers

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Biological liquid crystalline polymers are found in cellulosic, chitin, and DNA based natural materials. Chiral nematic liquid crystalline orientational order is observed frozen-in in the solid state in plant cell walls and is known as a liquid crystal analogue characterized by a helicoidal plywood architecture. The emergence of the plywood architecture by directed chiral nematic liquid crystalline self assembly has been postulated as the mechanism that leads to optimal cellulose fibril organization. In natural systems, tissue growth and development takes place in the presence of inclusions and secondary phases leaving behind characteristic defects and textures, which provide a unique testing ground for the validity of the liquid crystal self-assembly postulate. In this work, a mathematical model, based on the Landau-de Gennes theory of liquid crystals, is used to simulate defect textures arising in the domain of self assembly, due to presence of secondary phases representing plant cells, lumens and pit canals. It is shown that the obtained defect patterns observed in some plant cell walls are those expected from a truly liquid crystalline phase. The analysis reveals the nature and magnitude of the viscoelastic material parameters that lead to observed patterns in plant-based helicoids through directed self-assembly. In addition, the results provide new guidance to develop biomimetic plywoods for structural and functional applications.

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Section: Introductionmentioning

confidence: 99%

Modeling Textural Processes during Self-Assembly of Plant-Based Chiral-Nematic Liquid Crystals

Murugesan

Rey

2010

Polymers

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“…The above assumption was verified experimentally [29,36]. The occurrence of corresponding thermodynamic transitions in such systems is the most reliable criterion of belonging them to liquid crystal systems [28,37].…”

Section: Synovia As Liquid Crystal Biological Fluidmentioning

confidence: 89%

“…However, the above effect of the regular structure of cartilage surfaces on their friction can be explained proceeding from the properties of the liquid crystal compounds contained in synovia [32,36]. According to the data of [49], there is a close correlation between the regular microrelief of solid surfaces and the formation of planar-oriented liquid crystal films.…”

Section: P Mpamentioning

confidence: 99%

Effect of Liquid Crystals on Biological Mechanisms of Reducing Joint Friction

Ermakov

Белецкий²,

Eismont³

et al. 2015

Liquid Crystals in Biotribology

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The results of studying the friction of joint cartilages lubricated by synovia and lubricants without and with additives of liquid crystal compounds are presented. Based on the experimental data, the structural-mechanical and antifriction properties of joint synovia are compared. It is shown that, having in mind the regular structure of surface layers and deformation behavior of cartilages, the present results confirm the assumption on liquid crystal compounds as a cause of low friction in joints. The best tribological characteristics for the combinations with blood serum are demonstrated by drugs based on chondroitin sulfate, which display characteristics close to natural synovial fluid during frictional interaction of cartilage.The liquid crystal state seems to be an ideal medium for the occurrence of many biochemical reactions and the provision of the reproduction of biological structures. It is characteristic of cell membranes and organelles, photoreceptors of retina, microfibrils, collagen albumens, myelin nerve fibers, nucleic acids, saliva, and other natural objects [1][2][3][4]. The joint synovia also belongs to these objects. Its mesomorphic state may play an important role in reducing joint friction. Effect of Friction Surfaces and Lubricant on Joint Cartilage FrictionProceeding from modern ideas on anatomical, physiological, and biochemical features of members of the human and animal locomotor system including mechanisms of joint lubrication it is important to study the boundary lubrication of cartilages which occurs under heavy loads because collagen fibers are brought together. According to the generally accepted concept, low friction under these conditions should result from the formation of adsorbed films on friction surfaces. The latter are effectively separated by the films acting like boundary films of fatty acids, i.e. surfactants whose molecules are elongated and produce polymolecular adsorbed films normal to the friction surfaces [5][6][7]. Such structures are known to be characteristic of smectic liquid crystals. Since synovia contains acid components [8] it can be assumed that low friction in the boundary lubrication of cartilages is due to the mechanism of the action of fatty acids, i.e. the substances capable of forming smectic liquid crystal structures on bearing surfaces.Results of these studies are of interest for the following reasons. The lubricating behavior of the systems containing fatty acids is known to be governed by features of the structure of lubricating films in the zone of dynamic contact between solids rather than the lubricant rheological behavior [9,10]. Fatty acids of the biological origin belong to smectic liquid crystals characterized by a low shear resistance because shear in friction is localized in adsorbed lubricant films [10][11][12][13][14][15]. The use of fatty acids as surfactants to reduce friction is most effective when the nature of the friction surfaces provides chemical reactions between them and the acids [10,16].The assumption that synovia dem...

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“…In this context, Kupchinov et al 4 determined that synovial liquid contains about 2% nematic liquid crystals, to which important lubrication effects have been associated. The particular rheological properties and bio-compatibility of nematic lyotropic liquid crystals made of natural phospholipids makes them excellent candidates to be used as lubricants in joints of medical prosthesis for articial implants and in potential therapeutic applications.…”

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confidence: 99%

Effect of shape and bending modulus on the properties of nematic lyotropic liquid crystals

et al. 2016

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Synovial liquid is a natural lubricant of articular joints, such as shoulders, knees and hips. Thus, the development of biocompatible lubricants that can be employed in medical prosthesis for artificial implants, and eventually in certain therapies against osteo-arthritis or rheumatoid-arthritis diseases, is of an undoubted importance. Lyotropic liquid crystals have been used in the synthesis of silica and metals containing regularly oriented nanoporous, to obtain oriented carbon nanotube materials, in several pharmaceutical applications, as membrane mimetics and in lubrication applications. In this context, a new nematic lyotropic liquid crystal has been developed based on tetradecyltrimethyl ammonium chloride (TTAC), decanol (DeOH), a natural mixture of lipids (PL) extracted from soybean and sodium chloride (NaCl), all dissolved in water. A 30% w/w increase in TTAC content respect a certain composition of reference produces a more than 24-fold increase in the macroscopic viscosity of the solution. To understand the molecular principles that explain this behavior, several experimental and theoretical studies have been carried out. In this regard,

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Role of liquid crystals in the lubrication of living joints

Cited by 22 publications

References 4 publications

Modeling Textural Processes during Self-Assembly of Plant-Based Chiral-Nematic Liquid Crystals

Modeling Textural Processes during Self-Assembly of Plant-Based Chiral-Nematic Liquid Crystals

Effect of Liquid Crystals on Biological Mechanisms of Reducing Joint Friction

Effect of shape and bending modulus on the properties of nematic lyotropic liquid crystals

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