Processing Natural and Reconstituted Silk Solutions Under Equilibrium and Non-Equilibrium Conditions

1992 ◽  
Vol 292 ◽  
Author(s):  
Christopher Viney ◽  
Anne E. Huber ◽  
Dwayne L. Dunaway ◽  
Steven T. Case ◽  
David L. Kaplan
Keyword(s):  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Aquatic Insect ◽  
Liquid Crystalline Phase ◽  
Isotropic Phase ◽  
Insect Larvae ◽  
Equilibrium Conditions ◽  
Wide Range ◽  
Anisotropic Structures

AbstractA variety of natural silk secretions (from spiders, silkworms and aquatic insect larvae), and also reconstituted silk solutions, are able to form a nematic liquid crystalline phase. The anisotropic structures that self-assemble in this phase are formed from the isotropic phase by aggregation of molecules, rather than by individual molecules undergoing a conformational change to a rod-like form. This enables the molecules to retain their solubility in water while, simultaneously, the viscosity of the solution is reduced. The liquid crystalline phase is stable under a wide range of equilibrium conditions, but its ability to form is sensitive to the rate at which the initially isotropic solution is allowed to dry. The kinetics of phase transitions exhibited by solutions of silk proteins must be taken into account if solutions of silk fibroin are to be successfully processed in vitro.

Monodomain alignment of the smectic-A liquid crystalline phase from the isotropic phase

2008 ◽  
Vol 104 (4) ◽  
pp. 044902 ◽  
Author(s):  
Mitya Reznikov ◽  
Bentley Wall ◽  
Mark A. Handschy ◽  
Philip J. Bos
Keyword(s):  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Liquid Crystalline Phase ◽  
Isotropic Phase ◽  
Smectic A

Dynamics of liquid crystalline phase transition in sedimenting platelet-like particles

Soft Matter ◽  
2018 ◽  
Vol 14 (16) ◽  
pp. 3049-3056 ◽  
Author(s):  
Jize Sui ◽  
Yiming Ding ◽  
Masao Doi
Keyword(s):  
Phase Transition ◽  
Crystalline Phase ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Liquid Crystalline Phase ◽  
Isotropic Phase ◽  
Closed Container ◽  
Crystalline Phase Transition

When a suspension of platelet-like particles sediment in a closed container, the particles undergo isotropic–nematic phase transition (I–N transition), and there appears a clear interface between the isotropic phase and the nematic phase.

scholarly journals TheIn VitroLipolysis of Lipid-Based Drug Delivery Systems: A Newly Identified Relationship between Drug Release and Liquid Crystalline Phase

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Lu Xiao ◽  
Tao Yi ◽  
Ying Liu ◽  
Hua Zhou
Keyword(s):  
Drug Delivery ◽  
Crystalline Phase ◽  
Drug Delivery Systems ◽  
Liquid Crystalline ◽  
Delivery Systems ◽  
Liquid Crystalline Phase ◽  
Type I ◽  
Type Ii ◽  
Type Iv

The purpose of this study was to offer a new insight into the microstructure changes duringin vitrolipolysis of five lipid-based drug delivery formulations belonging to different lipid formulation types. Five lipid-based formulations of indomethacin were investigated using anin vitrolipolysis model. During lipolysis, microstructures of the intermediate phase formed by lipolytic products were observed. The results showed that the time of liquid crystal formation duringin vitrodigestion for these formulations was Type I > Type II > Type IIIB > Type IV > Type IIIA (p<0.05). After lipolysis, the drug releases from these formulations were determined. The results showed that the amount of drug distributed in the aqueous phase, obtained by ultracentrifuge after lipolysis, was, astonishingly, in inverse rank order of the above mentioned, that is, Type IIIA > Type IV > Type IIIB > Type II > Type I (p<0.05). These results showed that the liquid crystalline phase probably has a critical influence on the fate of the drug duringin vitrolipolysis and suggested that the liquid crystalline phase facilitated drug precipitation. These findings may improve the understanding of lipolysis of lipid-based drug delivery systems for designing better delivery system.

RNAi mediated IL-6 in vitro knockdown in psoriasis skin model with topical siRNA delivery system based on liquid crystalline phase

2016 ◽  
Vol 105 ◽  
pp. 50-58 ◽  
Author(s):  
Lívia Vieira Depieri ◽  
Lívia Neves Borgheti-Cardoso ◽  
Patrícia Mazureki Campos ◽  
Katia Kaori Otaguiri ◽  
Fabiana Testa Moura de Carvalho Vicentini ◽  
...  
Keyword(s):  
Delivery System ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Sirna Delivery ◽  
Liquid Crystalline Phase ◽  
Skin Model ◽  
Sirna Delivery System

scholarly journals Electron transfer studies of a conventional redox probe in human sweat and saliva bio-mimicking conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. Krishnaveni ◽  
V. Ganesh
Keyword(s):  
Electron Transfer ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Transfer Reaction ◽  
Electron Transfer Reaction ◽  
Redox Couple ◽  
Liquid Crystalline Phase ◽  
Transfer Reactions ◽  
Redox Probe ◽  
Human Sweat

AbstractModern day hospital treatments aim at developing electrochemical biosensors for early diagnosis of diseases using unconventional human bio-fluids like sweat and saliva by monitoring the electron transfer reactions of target analytes. Such kinds of health care diagnostics primarily avoid the usage of human blood and urine samples. In this context, here we have investigated the electron transfer reaction of a well-known and commonly used redox probe namely, potassium ferro/ferri cyanide by employing artificially simulated bio-mimics of human sweat and saliva as unconventional electrolytes. Typically, electron transfer characteristics of the redox couple, [Fe(CN)6]3−/4− are investigated using electrochemical techniques like cyclic voltammetry and electrochemical impedance spectroscopy. Many different kinetic parameters are determined and compared with the conventional system. In addition, such electron transfer reactions have also been studied using a lyotropic liquid crystalline phase comprising of Triton X-100 and water in which the aqueous phase is replaced with either human sweat or saliva bio-mimics. From these studies, we find out the electron transfer reaction of [Fe(CN)6]3−/4− redox couple is completely diffusion controlled on both Au and Pt disc shaped electrodes in presence of sweat and saliva bio-mimic solutions. Moreover, the reaction is partially blocked by the presence of lyotropic liquid crystalline phase consisting of sweat and saliva bio-mimics indicating the predominant charge transfer controlled process for the redox probe. However, the rate constant values associated with the electron transfer reaction are drastically reduced in presence of liquid crystalline phase. These studies are essentially carried out to assess the effect of sweat and saliva on the electrochemistry of Fe2+/3+ redox couple.

Liquid crystalline phase transitions in hexakis(4-(4′-heptyloxy)biphenoxy)cyclotriphosphazene

1995 ◽  
Vol 18 (5) ◽  
pp. 795-800 ◽  
Author(s):  
K. Moriya ◽  
H. Mizusaki ◽  
M. Kato ◽  
S. Yano ◽  
M. Kajiwara
Keyword(s):  
Phase Transitions ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Liquid Crystalline Phase

scholarly journals Influence of applied electric fields on the positive magneto-LC effects observed in the ferroelectric liquid crystalline phase of a chiral nitroxide radical compound

Soft Matter ◽  
2013 ◽  
Vol 9 (18) ◽  
pp. 4687 ◽  
Author(s):  
Katsuaki Suzuki ◽  
Yoshiaki Uchida ◽  
Rui Tamura ◽  
Yohei Noda ◽  
Naohiko Ikuma ◽  
...  
Keyword(s):  
Electric Fields ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Nitroxide Radical ◽  
Liquid Crystalline Phase
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