Stationary and transient acoustically induced birefringence of methyl acetate molecules dissolved in ethanol

Stogiannidis, G.; Tsigoias, S.; Kaziannis, S.; Kalampounias, Angelos G.

doi:10.1007/s11696-020-01052-1

Cited by 6 publications

(6 citation statements)

References 37 publications

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“…In Figure 3, two representative examples of the fitting procedure using Equation (4) corresponding to the decay region of the birefringence signal are shown. Pure liquids and mixtures composed of small molecules usually represent a relatively fast response [17]. Nevertheless, in the system studied in this work, the self-organization of SLS and the formation of larger supramolecular aggregates of the SLS@ASPH lead to a more perplexed structure, and the underlying dynamics are slower.…”

Section: Preparation and Characterization Of Micellementioning

confidence: 97%

“…The application of an ultrasonic field of a specific frequency on an isotropic liquid induces differences in the refractive index ∆n related to the n ⊥ and n // that correspond to the refractive indexes, which are perpendicular and parallel to the direction of the sound wave propagation, respectively. The experimental setup for the transient acoustically induced birefringence was described in detail in [11,17]. In brief, an acousto-optical cell made of glass was filled completely with the liquid sample and thermo-stated at the desired temperature.…”

Section: Determination Of Cmc Via Ultrasonic Velocitymentioning

confidence: 99%

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Non-Steroidal Anti-Inflammatory Drugs Loaded to Micelles for the Modulation of Their Water Solubility

Banti,

Kalampounias,

Hadjikakou

2023

IJMS

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The low water solubility of aspirin (ASPH) is well known, creating research challenges regarding both its composition and its delivery. Therefore, the development of new aspirin-based formulations that are water soluble is a research, technological, and financial issue. With the aim to improve the water solubility of ASPH, the micelle of formula SLS@ASPH (SLS = Sodium Lauryl Sulfate) was formed. The Critical Micelle Concentration (CMC) of SLS in the presence of ASPH was determined by ultrasonic velocity, complementary, and transient birefringence measurements. The SLS@ASPH was characterized by the melting point (m.p.), attenuated total reflection spectroscopy (FT-IR-ATR), and X-ray fluorescence spectroscopy (XRF) in a solid state and in a solution by ultraviolet-visible (UV-Vis) and 1H NMR spectroscopies. The SLS/ASPH molar ratio was determined to be 5/1 in SLS@ASPH. The inhibitory activity of SLS@ASPH towards lipoxygenase (LOX), an enzyme that takes part in the inflammation mechanism, was studied. The inhibitory activity of SLS@ASPH against LOX is 3.5-fold stronger than that of free SLS. The in vitro toxicity of the SLS@ASPH was tested on immortalized human keratinocyte (HaCaT) cells.

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Section: Preparation and Characterization Of Micellementioning

confidence: 97%

Section: Determination Of Cmc Via Ultrasonic Velocitymentioning

confidence: 99%

Non-Steroidal Anti-Inflammatory Drugs Loaded to Micelles for the Modulation of Their Water Solubility

Banti,

Kalampounias,

Hadjikakou

2023

IJMS

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“…The optical ultrasonically induced birefringence measurements were carried out by means of a laboratory-made setup, which is described in detail previously [14][15][16]. In brief, the ultrasonically induced birefringence signals were measured after completely loading the acoustic cell with the solution, eliminating possible directional flow or liquid sharing.…”

Section: Ultrasonically Induced Optical Birefringence Measurementsmentioning

confidence: 99%

Combined Use of Ultrasonic and Electromagnetic Fields for the Study of Bonding Mechanisms between Dexamethasone Disodium Phosphate Molecules

Kouderis

Kalampounias

2023

QuBS

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We have investigated the ultrasonically induced birefringence traces of aqueous solutions of dexamethasone disodium phosphate, a derivative of hydrocortisone (cortisol). The stationary birefringence and the transient built-up and decay relaxation processes were studied as a function of solution concentration, ultrasound frequency and intensity, as well as a function of temperature. The results were analyzed in view of structural peculiarities of the system in an effort to gain further insights into the molecular relaxation dynamics and the proposed self-association process occurring in the system. The detected ultrasonically induced birefringence relaxation is motivated by the rotational diffusion of dexamethasone disodium phosphate aggregates due to self-association depending on the solution concentration. The observed relaxation mechanism is directly linked to the hydrodynamic size of the acoustic field-induced self-assembly. The systematic analysis of the transient birefringence signals caused by the applied ultrasonic field allowed us to evaluate the interplay between permanent and induced dipoles with changing concentration, temperature, and ultrasound properties. The birefringence traces are adequately fitted with a stretched exponential law indicating the polydispersive nature of the self-aggregated molecular structures. The obtained results are described in the light of recent studies performed on this system.

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“…For measuring the transient acoustically-induced birefringence, we used an instrument depicted in Figure 4. Its components have been described in detail elsewhere [39]. A solution of the sample was loaded in a cylindrically-shaped and thermostated non-birefringent glass cell with 1 cm optical path-length.…”

Section: Transient Acoustically-induced Birefringence Measurementsmentioning

confidence: 99%

“…These constraints induce molecular libration relaxation on a femtosecond timescale, which is ultrafast and beyond the limits of the ultrasonically-induced birefringence technique. Molecular liquids and their mixtures exhibit usually fast birefringence response (see, e.g., [39] and references therein). In the case of SLS@TC and CTAB@TC dilute solutions, a relatively slower response is observed because of the peculiar nature of the underlying dynamics, where a self-organization into larger supramolecular aggregates takes place, leading to a dynamically complex structure.…”

Section: Transient Acoustically-induced Birefringence Measurementsmentioning

confidence: 99%

Tetracycline Water Soluble Formulations with Enhanced Antimicrobial Activity

et al. 2020

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The negligible water solubility of tetracycline (TC), a well-known antibiotic of clinical use, is the major disadvantage for its oral administration. With the aim to improve the water solubility of TC, the micelles of formulae SLS@TC and CTAB@TC (SLS = sodium lauryl sulphate and CTAB = cetrimonium bromide) were synthesized. The micelles SLS@TC and CTAB@TC were characterized by melting point (m.p.), thermogravimetric differential thermal analysis (TG-DTA), differential scanning calorimetry (DTG/DSC), attenuated total reflection spectroscopy (FT-IR-ATR), ultra-violet visible (UV/vis) spectroscopy, proton nucleus magnetic resonance (1H-NMR) spectroscopy, and the ultrasonically-induced biregringence technique. The antimicrobial activity of SLS@TC and CTAB@TC was evaluated, by means of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and inhibition zone (IZ), against the Gram negative bacterial strains Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli) and the Gram positive ones of the genus of Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus). Generally, both micelles show better activity than that of TC against the microbial strains tested. Thus, the MIC value of CTAB@TC is 550-fold higher than that of free TC against S. epidermidis. Despite the stronger activity of CTAB@TC than SLS@TC against both Gram negative and Gram positive microbes, SLS@TC is classified as a bactericidal agent (in that it eliminates 99.9% of the microbes), in contrast to CTAB@TC, which is bacteriostatic one (inhibits, but does not kill the organisms). The toxicity of SLS@TC and CTAB@TC was evaluated against human corneal eukaryotic cells (HCECs). Moreover, SLS@TC and CTAB@TC exhibit low in vivo toxicity against Artemia salina, even at concentrations up to threefold higher than those of their MICmax. Therefore, SLS@TC and CTAB@TC can be candidates for the development of new antibiotics.

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Stationary and transient acoustically induced birefringence of methyl acetate molecules dissolved in ethanol

Cited by 6 publications

References 37 publications

Non-Steroidal Anti-Inflammatory Drugs Loaded to Micelles for the Modulation of Their Water Solubility

Non-Steroidal Anti-Inflammatory Drugs Loaded to Micelles for the Modulation of Their Water Solubility

Combined Use of Ultrasonic and Electromagnetic Fields for the Study of Bonding Mechanisms between Dexamethasone Disodium Phosphate Molecules

Tetracycline Water Soluble Formulations with Enhanced Antimicrobial Activity

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