NMR investigation of the thermogelling properties, anomalous diffusion, and structural changes in a Pluronic F127 triblock copolymer in the presence of gold nanoparticles

Ojha, Jyotsana; Nanda, Raju; Dorai, Kavita

doi:10.1007/s00396-020-04740-2

Cited by 8 publications

(6 citation statements)

References 91 publications

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“…However, the PPG-CH 3 protons resonance signal peak broadens and upfield shifts to 1.10 ppm, and its multiplet structure disappears, indicating that the PPG blocks seem to form a hydrophobic core. 40,41 Combining these spectra, we conclude that the assembly process forms an ordered CANs structure driven by hydrogen bonding and hydrophilic interactions (Figure 2e). Molecular Arrangements of the Spiral Ru-CANs.…”

Section: Synthesis Of Thementioning

confidence: 72%

Spiral Square Nanosheets Assembled from Ru Clusters

Han

et al. 2023

J. Am. Chem. Soc.

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Spiral two-dimensional (2D) nanosheets exhibit unique physical and chemical phenomena due to their twisted structures. While self-assembly of clusters is an ideal strategy to form hierarchical 2D structures, it is challenging to form spiral nanosheets. Herein, we first report a screw dislocation involved assembled method to obtain 2D spiral cluster assembled nanosheets (CANs) with uniform square morphology. The 2D spiral Ru CANs with a length of approximately 4 μm and thickness of 20.7 ± 3.0 nm per layer were prepared via the assembly of 1–2 nm Ru clusters in the presence of molten block copolymer Pluronic F127. Cryo-electron microscopy (cryo-EM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) demonstrate the existence of screw dislocation in the spiral assembled structure. The X-ray absorption fine structure spectrum indicates that Ru clusters are Ru3+ species, and Ru atoms are mainly coordinated with Cl with a coordination number of 6.5. Fourier-transform infrared (FT-IR) spectra and solid-state nuclear magnetic resonance hydrogen spectra (1H NMR) indicate that the assembly process of Ru clusters is formed by noncovalent interactions, including hydrogen bonding and hydrophilic interactions. Additionally, the Ru-F127 CANs exhibit excellent photothermal conversion performance in the near-infrared (NIR) region.

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Section: Synthesis Of Thementioning

confidence: 72%

Spiral Square Nanosheets Assembled from Ru Clusters

Han

et al. 2023

J. Am. Chem. Soc.

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“…To demonstrate the design of the bath, 1 H NMR studies were carried out for the pure H-HPMC solution, pure PF-127 solution, and the combination of PF-127/H-HPMC (Figure a). The spectrum of PF-127 had three main groups of peaks at 3.73, 3.57, and 1.18 ppm, arising from the −CH 2 group protons from the PEO segment, the −CH 2 group protons from the PPO segment, and the −CH 3 group protons from the PPO segment, respectively. , These peaks varied with the addition of H-HPMC, and the chemical shifts of protons are depicted in Figure a(ii–iv), showing the interaction between H-HPMC and PF-127. After adding H-HPMC, peaks of both PPO-CH 2 and PPO-CH 3 broadened and the multiplet splitting of the PPO-CH 2 peak disappeared, indicating a reduced mobility of PPO groups, which occurred due to the enhanced viscosity, and the hydrophobic association between PPO groups and H-HPMC.…”

Section: Resultsmentioning

confidence: 97%

Regulable Supporting Baths for Embedded Printing of Soft Biomaterials with Variable Stiffness

Gao

Yin

et al. 2022

ACS Appl. Mater. Interfaces

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Three-dimensional (3D) embedded printing is emerging as a potential solution for the fabrication of complex biological structures and with ultrasoft biomaterials. For the supporting medium, bulk gels can support a wide range of bioinks with higher printing resolution as well as better finishing surfaces than granular microgel baths. However, the difficulties of regulating the physical properties of existing bulk gel supporting baths limit the further development of this method. This work has developed a bulk gel supporting bath with easily regulable physical properties to facilitate soft-material fabrication. The proposed bath is composed based on the hydrophobic association between a hydrophobically modified hydroxypropylmethyl cellulose (H-HPMC) and Pluronic F-127 (PF-127). Its rheological properties can be easily regulated; in the preprinting stage by varying the relative concentration of components, during printing by changing the temperature, and postprinting by adding additives with strong hydrophobicity or hydrophilicity. This has made the supporting bath not only available for various bioinks with a range of printing windows but also easy to be removed. Also, the removal strategy is independent of printing conditions like temperature and ions, which empowers the bath to hold great potential for the embedded printing of commonly used biomaterials. The adjustable rheological properties of the bath were leveraged to characterize the embedded printing quantitatively, involving the disturbance during the printing, filament cross-sectional shape, printing resolution, continuity, and the coalescence between adjacent filaments. The match between the bioink and the bath was also explored. Furthermore, low-viscosity bioinks (with 0.008–2.4 Pa s viscosity) were patterned into various 3D complex delicate soft structures (with a 0.5–5 kPa compressive modulus). It is believed that such an easily regulable assembled bath could serve as an available tool to support the complex biological structure fabrication and open unique prospects for personalized medicine.

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“…Pluronic ® F-127 has a triblock polymer with two hydrophilic tails in the structure. Interactions were observed between the methyl and methylene groups of the PPO segment in Pluronic ® F-127, suggesting the construction of micellar structures [31], as illustrated in Figure 9. Cryo-TEM observation results also supported the particle structure.…”

Section: Discussionmentioning

confidence: 97%

Development of Self-Administered Formulation to Improve the Bioavailability of Leuprorelin Acetate

et al. 2022

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In recent years, the development of self-injectable formulations has attracted much attention, and the development of formulations to control pharmacokinetics, as well as drug release and migration in the skin, has become an active research area. In the present study, the development of a lipid-based depot formulation containing leuprorelin acetate (LA) as an easily metabolizable drug in the skin was prepared with a novel non-lamellar liquid-crystal-forming lipid of mono-O-(5,9,13-trimethyl-4-tetradecenyl) glycerol ester (MGE). Small-angle X-ray scattering, cryo-transmission electron microscopy, and nuclear magnetic resonance observations showed that the MGE-containing formulations had a face-centered cubic packed micellar structure. In addition, the bioavailability (BA) of LA after subcutaneous injection was significantly improved with the MGE-containing formulation compared with the administration of LA solution. Notably, higher Cmax and faster Tmax were obtained with the MGE-containing formulation, and the BA increased with increasing MGE content in the formulation, suggesting that LA migration into the systemic circulation and its stability might be enhanced by MGE. These results may support the development of self-administered formulations of peptide drugs as well as nucleic acids, which are easily metabolized in the skin.

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NMR investigation of the thermogelling properties, anomalous diffusion, and structural changes in a Pluronic F127 triblock copolymer in the presence of gold nanoparticles

Cited by 8 publications

References 91 publications

Spiral Square Nanosheets Assembled from Ru Clusters

Spiral Square Nanosheets Assembled from Ru Clusters

Regulable Supporting Baths for Embedded Printing of Soft Biomaterials with Variable Stiffness

Development of Self-Administered Formulation to Improve the Bioavailability of Leuprorelin Acetate

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