Dielectric Study of Liposome Dispersion Using Statistical Analysis of Jitter

Hosoi, Yuzô; Kita, R.; Shinyashiki, Naoki; Yagihara, Shin

doi:10.14723/tmrsj.35.861

Cited by 7 publications

(7 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Though m-process, l1-process and dc conductivity term were not clearly observed in the relaxation curve, these processes were necessary for curve-fitting. It should be also noted that the relaxation curve and processes shown in Figure 5 are similar to results obtained for previously reported liposome suspensions of 1,2-dipalmitoylsn-glycero-3-phosphacholine (DPPC) [38,39], and are important in the subsequent relaxation parameter analysis.…”

Section: Dielectric Relaxation Curvessupporting

confidence: 85%

“…The dielectric behavior of the relaxation parameter of the h-process shown in Figure 6 reflects the dynamics of the polar head group of the N-oleyl lactobionamide molecule, as shown in DPPC liposome [38,39]. This is quite reasonable for h-process, since the relaxation process reflects the dynamics of a hydrogen-bonding network involving water molecules and is affected by interactions with the head groups of the N-oleyl lactobionamide molecules.…”

Section: H-processmentioning

confidence: 80%

“…The smaller βh values suggest that the degree of heterogeneity in dynamic behaviors of water molecules is larger in the mixture because of interacting N-oleyl lactobionamide. It has already been reported in the case of DPPC liposomes [38,39] that the fluctuation of the h-process for surrounding water molecules increases with increasing mobility of the hydrophilic head group of the DPPC molecules. The temperature dependence of βh changes significantly around the sol-gel transition temperature of 37.8 °C and also around 52.5 °C in the sol phase.…”

Section: H-processmentioning

confidence: 86%

See 2 more Smart Citations

Dielectric Study on Supramolecular Gels by Fiber Structure Formation from Low-Molecular-Weight Gelator/Water Mixtures

Shimizu

Abe

Kishi

et al. 2023

Gels

View full text Add to dashboard Cite

There are various types of gel materials used in a wide range of fields, and their gelation mechanisms are extremely diverse. Furthermore, in the case of hydrogels, there exist some difficulties in understanding complicated molecular mechanisms especially with water molecules interacting through hydrogen bonding as solvents. In the present work, the molecular mechanism of the structural formation of fibrous super-molecular gel by the low molecular weight gelator, N-oleyl lactobionamide/water mixture was elucidated using the broadband dielectric spectroscopy (BDS) method. The dynamic behaviors observed for the solute and water molecules indicated hierarchical structure formation processes in various time scales. The relaxation curves obtained at various temperatures in the cooling and heating processes showed relaxation processes respectively reflecting the dynamic behaviors of water molecules in the 10 GHz frequency region, solute molecules interacting with water in MHz region, and ion-reflecting structures of the sample and electrode in kHz region. These relaxation processes, characterized by the relaxation parameters, showed remarkable changes around the sol–gel transition temperature, 37.8 °C, determined by the falling ball method and over the temperature range, around 53 °C. The latter change suggested a structure formation of rod micelles appearing as precursors before cross-linking into the three-dimensional network of the supramolecular gels. These results clearly demonstrate how effective relaxation parameter analysis is for understanding the gelation mechanism in detail.

show abstract

Section: Dielectric Relaxation Curvessupporting

confidence: 85%

Section: H-processmentioning

confidence: 80%

Section: H-processmentioning

confidence: 86%

See 1 more Smart Citation

Dielectric Study on Supramolecular Gels by Fiber Structure Formation from Low-Molecular-Weight Gelator/Water Mixtures

Shimizu

Abe

Kishi

et al. 2023

Gels

View full text Add to dashboard Cite

show abstract

“…The NMR measurements should then reflect dynamic behaviors obtained from an average in the larger space and time scales. Nevertheless, the same conclusion of the existence of various mobile properties, or the broad distribution of water molecules, was obtained from [19], poly(ethylene glycol) (PEG) [19], poly(vinyl methyl ether) (PVME) [19], poly(ethylenimine) (PEI) [19], poly(acrylic acid) (PAA) [19], poly(allylamine) (PAlA) [19], Poly(N-isopropylacrylamide) (PNiPAM) [43], poly(acrylamide) (PAAm) [44], PAAm gels in water-acetone mixtures (PAAm gel Acetone) [20,44], PAAm gels in waterdimethyl sulfoxide mixtures (PAAm gel DMSO) [20], PAAm gels in water-1, 4-dioxane (PAAm gel 1, 4-dioxane) [20], trehalose [45,46], maltose [45,46], pullulan [47], glucose [45,46], rice [48], hydroxypropylmethylcellulose (HPMC) [46,49,50],1,2dipalmitoylsn-glycero-3-phosphacholine (liposome) [46,[51][52][53], denatured chicken egg white (glass egg) [46,54], ovalbumin (OVA) [46,[55][56][57][58], gelatin [46,58], bovine Achilles tendon (collagen) [46,58,59]. The red arrow indicates the maximum error estimated from the s value.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of water structures in cotton cloth by fractal analysis with broadband dielectric spectroscopy

et al. 2021

View full text Add to dashboard Cite

Broadband dielectric spectroscopy measurements were performed on naturally dried cotton cloth, and a recently developed analytical technique for fractal analysis of water structures was applied to obtain existential states and locations of water molecules in the material. Three relaxation processes observed in GHz, MHz, and kHz frequency regions were attributed to dynamic behaviors of hydrogen bonding networks (HBNs) of water and interacting molecules, polymer chains with interacting ion and water molecules, and ions restricted on the interfaces of larger structures, respectively. Water molecules were heterogeneously distributed in the cotton cloth, and the HBNs remained as a broad GHz frequency process. Fractal analysis suggested that water molecules distributed in the material were characterized by a small value (0.55) of the Cole–Cole relaxation time distribution parameter, indicating spatial distribution of HBN fragments with various sizes in cotton cloth. This result was also supported by the T2 relaxation time obtained from nuclear magnetic resonance for naturally dried cotton yarn. Comparing previous results of dielectric relaxation measurements and fractal analysis with the τ–β diagram for various aqueous systems, the results determined that water molecules cannot exist inside cellulose microfibrils. The fractal analysis employed in this work can be applied to dynamic water structures in any material. The presented analytical technique with a universal τ–β diagram is expected to be an effective tool to clarify water structure detail even for heterogeneous hydrations of the low water content substances. Graphical abstract

show abstract

“…These aggregation structures of excess softener agents with water molecules are also suggested from the ratio of De value for the MHz process against that for the GHz process, which does not increase with the softener agent concentration from 0.1 to 1.0% as shown in Table 3. The characteristic behavior of cotton samples with excess softener agent reflects the poly(ethylene glycol) (PEG) [38], poly(vinyl methyl ether) (PVME) [38], poly(ethylenimine) (PEI) [38], poly(acrylic acid) (PAA) [38], poly(allylamine) (PAlA) [38], poly(Nisopropylacrylamide) (PNiPAM) [49], poly(acrylamide) (PAAm) [50], PAAm gels in water-acetone mixtures (PAAm gel acetone) [50,51], PAAm gels in water-dimethyl sulfoxide mixtures (PAAm gel DMSO) [51], PAAm gels in water-1, 4-dioxane (PAAm gel 1, 4-dioxane) [51], trehalose [52,53], maltose [52,53], pullulan [54], glucose [52,53], rice [46], hydroxypropylmethylcellulose (HPMC) [53,55,56], 1,2-dipalmitoylsn-glycero-3phosphacholine (liposome) [53,[57][58][59], denatured chicken egg white (glass egg) [53,60], ovalbumin (OVA) [53,[61][62][63][64], gelatin [53,64], and bovine Achilles tendon (collagen) [52,64,65]. The plots obtained from the analysis of the GHz processes for naturally dry cotton ...…”

Section: And Cementmentioning

confidence: 99%

Fractal water structures affected by softener agent in cotton cloths

et al. 2022

View full text Add to dashboard Cite

Broadband dielectric spectroscopy (BDS) measurements were performed on cotton cloth samples with softener agents in natural environments, and a recent analytical technique of fractal analysis refined in dielectric spectroscopy was used for water structures. Three relaxation processes observed in the GHz, MHz, and kHz regions were attributed to the dynamic behaviors of hydrogen-bonding networks (HBNs) of water and interacting molecules, hydrated polymer chains, and ions restricted in the interfaces of large structures. Fractal analysis of the GHz region suggested that the GHz frequency process was retained, even in the dry state, revealing a broad spatial distribution of HBN fragments of various sizes. This typical tendency for heterogeneous hydration in cotton cloth was emphasized by the addition of a softener agent, as the value of Cole–Cole’s relaxation time distribution parameter changed from 0.55 to 0.41. The addition of the softener agent still retained the GHz frequency process, even in the dry state. This result means that the softener inhibited the formation of hydration sites on the cellulose surface and induced the dispersion of hydration sites. Thus, HBNs are fragmented by the softener agent. On the other hand, water molecules still aggregate to retain HBNs in a restricted area. The heterogeneous dispersion of HBN fragments broadens the GHz relaxation process, and the lower-frequency tail overlaps with the lower relaxation process because of chain dynamics with interacting water molecules. The structure formed by these water molecules, which is restricted by polymer chains and related to the stiffening effect of cotton fabric, is also heterogeneously hindered by the appropriate concentration of the softening agent. These indications were also consistent with the T2 relaxation time obtained using the Carr–Purcell–Meiboom–Gill method of nuclear magnetic resonance measurements and are consequently reflected in the hydration model for macroscopic properties of cotton fabric. Graphical abstract

show abstract

Dielectric Study of Liposome Dispersion Using Statistical Analysis of Jitter

Cited by 7 publications

References 15 publications

Dielectric Study on Supramolecular Gels by Fiber Structure Formation from Low-Molecular-Weight Gelator/Water Mixtures

Dielectric Study on Supramolecular Gels by Fiber Structure Formation from Low-Molecular-Weight Gelator/Water Mixtures

Evaluation of water structures in cotton cloth by fractal analysis with broadband dielectric spectroscopy

Fractal water structures affected by softener agent in cotton cloths

Contact Info

Product

Resources

About