scholarly journals Solubilization of Paclitaxel by Self-Assembled Amphiphilic Phospholipid-Mimetic Polymers with Varied Hydrophobicity

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2805
Author(s):  
Chie Kojima ◽  
Tomoka Hirose ◽  
Risa Katayama ◽  
Akikazu Matsumoto
Keyword(s):  
Medical Devices ◽  
Drug Delivery Systems ◽  
Drug Action ◽  
The Self ◽  
Butyl Methacrylate ◽  
Random Copolymers ◽  
Coating Agent ◽  
Self Assembling ◽  
Dodecyl Methacrylate ◽  
Self Assembled

2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers have been used as a coating agent on medical devices and as a carrier in drug delivery systems (DDSs). Paclitaxel (PTX) is a water-insoluble anticancer drug whose solubilizer is necessary for administration. Block and random copolymers composed of hydrophilic MPC and butyl methacrylate, named PMB, show different properties, depending on the polymer sequence and MPC content. In the present study, we used amphiphilic MPC polymers comprising hydrophobic dodecyl methacrylate (DMA). The self-assembling properties and PTX solubilization of random and block poly(MPC-co-DMA)s (rPMDs and bPMDs) with different compositions were examined and compared. rPMDs with high DMA content formed large and relatively loose self-assembled structures, which solubilized PTX. However, bPMDs formed small and compact self-assembled structures with poor PTX solubilization. PTX solubilized by PMB with small and loose self-assembled structures showed efficient drug action, similar to free PTX; however, rPMDs fell short of demonstrating PTX efficiency. Our results suggest that the self-assembling properties and the hydrophobicity of amphiphilic MPC polymers largely affect PTX solubilization as well as drug action, which is required to be controlled by the polymer sequence, as well as the structure and composition of the hydrophobic monomer for efficient DDS.

Synthesis of Platinum Nanoparticles and Then Self-Assembly on Nafion Membrane to Give a Catalyst Coated Membrane

2005 ◽  
Vol 2005 (7) ◽  
pp. 449-451 ◽  
Author(s):  
Haolin Tang ◽  
Zhiping Luo ◽  
Mu Pan ◽  
San Ping Jiang ◽  
Zhengcai Liu
Keyword(s):  
Self Assembly ◽  
Proton Exchange Membrane ◽  
Membrane Surface ◽  
Proton Exchange ◽  
The Self ◽  
Self Assembling ◽  
Self Assembled ◽  
Nanoparticle Structure ◽  
Exchange Membrane ◽  
Coated Membrane

A catalyst-coated membrane (CCM) for a proton exchange membrane fuel cell (PEMFC) with Pt loading of 2.8 μg/cm2 have been prepared by self-assembling charged Pt particles on a sulfonic acid function group, SO3-, on the membrane surface. Proton conductivity of the as-obtained CCM is 0.0932 S/cm. Half-cell polarisation showed that the self-assembled membrane is electrochemical active. Electrochemical characterisation of the self-assembled electrode showed that the Pt-PDDA nanoparticles were electrocatalytic active. The performance of self-assembled MEA with a Pt loading of 2.8 μg/cm2 achieved 2.3 mW/cm2. This corresponds to Pt utilisation of 821 W per 1 g Pt. The results demonstrated the feasibility of the formation of monolayered Pt nanoparticle structure on the membrane interface. Such a monolayered structure could offer a powerful tool in fundamental studies of polymer electrolyte systems.

Self-assembled Ordered Energetic Composites of CuO Nanorods and Nanowells and Al Nanoparticles with High Burn Rates

2005 ◽  
Vol 896 ◽  
Author(s):  
Senthil Subramanium ◽  
Shameem Hasan ◽  
Shantanu Bhattacharya ◽  
Yuanfang Gao ◽  
Steve Apperson ◽  
...  
Keyword(s):  
Self Assembly ◽  
Interfacial Area ◽  
The Self ◽  
Al Nanoparticles ◽  
Self Assembling ◽  
Vinyl Pyridine ◽  
Self Assembled ◽  
Burn Rate ◽  
Energetic Composites ◽  
Cuo Nanorods

AbstractCurrent approaches of mixing fuel and oxidizer nanoparticles or adding fuel nanoparticles to oxidizer gel lead to an overall reduced interfacial area of contact between them and thus, limit their burn rates severely. We have developed an approach of self-assembling fuel nanoparticles around an oxidizer matrix using a monofunctional polymer, poly(4)-vinyl pyridine (P4VP). The polymer has been used to accomplish binding of fuel and oxidizer in a molecularly engineered manner. We use composite of Al-nanoparticles and CuO nanorods for executing this self-assembly. TEM images of this composite confirms the self-assembly of Al-nanoparticles around the oxidizer nanorods. The burn rate of self-assembled composite has been found significantly higher than that of the composite prepared by simple mixing.

Performance of Direct Formic Acid Fuel Cell With Self-Assembled PEMs

2006 ◽  
Author(s):  
Haolin Tang ◽  
Mu Pan ◽  
Shichun Mu ◽  
Zhaohui Wan ◽  
Runzhang Yuan
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Liquid Fuel ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
The Self ◽  
Self Assembling ◽  
Satisfactory Performance ◽  
Self Assembled ◽  
Commercial Applications

Direct liquid fuel cells have attracted intensive research because of the promised application in Portable Fuel Cell Systems. Liquid fuel crossover through the proton exchange membranes (PEMs, e.g. Nafion™ membrane) is one of the major obstacles that currently prevent the widespread commercial applications of direct liquid fuel cell. In this paper, PEMs constructed by self-assembling metal nanoparticles on Nafion™ membranes were prepared to probe the crossover behaviors. The results show that the fuel crossover has a remarkable decrease comparing with the original PEMs. This satisfactory performance gives the self-assembled PEMs a promised prospect in direct liquid fuel cells.

scholarly journals Preparation of Composite Materials from Self-Assembled Chitin Nanofibers

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3548
Author(s):  
Jun-ichi Kadokawa
Keyword(s):  
Composite Materials ◽  
Short Review ◽  
The Self ◽  
Material Source ◽  
Bottom Up ◽  
Nanostructured Composite ◽  
Self Assembling ◽  
Self Assembled ◽  
Polymeric Substrates ◽  
Chitin Nanofibers

Although chitin is a representative abundant polysaccharide, it is mostly unutilized as a material source because of its poor solubility and processability. Certain specific properties, such as biodegradability, biocompatibility, and renewability, make nanofibrillation an efficient approach for providing chitin-based functional nanomaterials. The composition of nanochitins with other polymeric components has been efficiently conducted at the nanoscale to fabricate nanostructured composite materials. Disentanglement of chitin microfibrils in natural sources upon the top-down approach and regeneration from the chitin solutions/gels with appropriate media, such as hexafluoro-2-propanol, LiCl/N, N-dimethylacetamide, and ionic liquids, have, according to the self-assembling bottom-up process, been representatively conducted to fabricate nanochitins. Compared with the former approach, the latter one has emerged only in the last one-and-a-half decade. This short review article presents the preparation of composite materials from the self-assembled chitin nanofibers combined with other polymeric substrates through regenerative processes based on the bottom-up approach.

Nanoscale Self-Assembly Using Ion and Electron Beam Techniques: A Rapid Review

MRS Advances ◽  
2020 ◽  
Vol 5 (64) ◽  
pp. 3507-3520
Author(s):  
Chunhui Dai ◽  
Kriti Agarwal ◽  
Jeong-Hyun Cho
Keyword(s):  
Electron Beam ◽  
Self Assembly ◽  
Ion Beam ◽  
Three Dimensional ◽  
The Self ◽  
Stress Generation ◽  
Rapid Review ◽  
High Yield ◽  
3D Nanostructures ◽  
Self Assembled

AbstractNanoscale self-assembly, as a technique to transform two-dimensional (2D) planar patterns into three-dimensional (3D) nanoscale architectures, has achieved tremendous success in the past decade. However, an assembly process at nanoscale is easily affected by small unavoidable variations in sample conditions and reaction environment, resulting in a low yield. Recently, in-situ monitored self-assembly based on ion and electron irradiation has stood out as a promising candidate to overcome this limitation. The usage of ion and electron beam allows stress generation and real-time observation simultaneously, which significantly enhances the controllability of self-assembly. This enables the realization of various complex 3D nanostructures with a high yield. The additional dimension of the self-assembled 3D nanostructures opens the possibility to explore novel properties that cannot be demonstrated in 2D planar patterns. Here, we present a rapid review on the recent achievements and challenges in nanoscale self-assembly using electron and ion beam techniques, followed by a discussion of the novel optical properties achieved in the self-assembled 3D nanostructures.

Directive Effect of Chain Length in Modulating Peptide Nano-assemblies

2020 ◽  
Vol 27 (9) ◽  
pp. 923-929
Author(s):  
Gaurav Pandey ◽  
Prem Prakash Das ◽  
Vibin Ramakrishnan
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Light Scattering ◽  
Chain Length ◽  
Self Assembly ◽  
The Self ◽  
Ionic Charge ◽  
Self Assembling ◽  
Biophysical Techniques

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.

A Solvent-Dependent and Electrochemically Controlled Self-Assembling/Disassembling System

2003 ◽  
Vol 68 (9) ◽  
pp. 1647-1662 ◽  
Author(s):  
Valeria Amendola ◽  
Massimo Boiocchi ◽  
Yuri Diaz Fernandez ◽  
Carlo Mangano ◽  
Piersandro Pallavicini
Keyword(s):  
Equilibrium Mixture ◽  
Bidentate Ligand ◽  
Molecular Structures ◽  
The Self ◽  
Molar Ratio ◽  
Crystal And Molecular Structures ◽  
Self Assembling ◽  
Irreversible Oxidation ◽  
Irreversible Reduction ◽  
Metal Ligand

The bis-bidentate ligand R,S-1,2-diphenyl-N,N'-bis(2-quinolinemethylidene)ethane-1,2-diamine (ligand 4), containing two (iminomethyl)quinoline moieties separated by a cis-1,2-diphenylethylene spacer, forms stable complexes with both CuI and CuII. With CuII, the monomeric 1:1 complex [CuII(4)]2+ is obtained both in CH3CN and CH2Cl2. With CuI and overall 1:1 metal/ligand molar ratio, an equilibrium mixture is obtained in CH3CN, consisting of [CuI(4)2]+, [CuI2(4)2]2+ and [CuI2(4)(CH3CN)4]2+. The preponderant species is the two-metal one-ligand "open" complex [CuI2(4)(CH3CN)4]2+, in which each Cu+ cation is coordinated in a tetrahedral fashion by one (iminomethyl)quinoline unit and by two CH3CN molecules. Precipitation from the equilibrium mixture yields only crystals of [CuI2(4)(CH3CN)4](ClO4)2·2CH3CN, whose crystal and molecular structures have been determined. On the other hand, in the poorly coordinating CH2Cl2 solvent, only the dimeric helical [CuI2(4)2]2+ complex is obtained, when the overall metal/ligand 1:1 molar ratio is chosen. Addition of large quantities of acetonitrile to solutions of [CuI2(4)2]2+ in dichlorometane results in the formation of [CuI2(4)(CH3CN)4]2+, i.e. in the solvent-driven disassembling of the CuI helicate. While electrochemistry in CH3CN is poorly defined due to the presence of more than one CuI species, cyclic voltammetry experiments carried out in CH2Cl2 revealed a well defined behavior, with irreversible oxidation of [CuI2(4)2]2+ and irreversible reduction of [CuII(4)]2+ taking place at separate potentials (∆E ≈ 700 mV). Irreversibility and separation of the redox events are due to the self-assembling and disassembling processes following the reduction and oxidation, respectively.

Self-assembling behaviour of a modified aromatic amino acid in competitive medium

Soft Matter ◽  
2020 ◽  
Vol 16 (28) ◽  
pp. 6599-6607 ◽  
Author(s):  
Pijush Singh ◽  
Souvik Misra ◽  
Nayim Sepay ◽  
Sanjoy Mondal ◽  
Debes Ray ◽  
...  
Keyword(s):  
Amino Acid ◽  
Self Assembly ◽  
Aromatic Amino Acid ◽  
Photophysical Properties ◽  
Solvent Mixture ◽  
The Self ◽  
Solvent Ratio ◽  
Self Assembling

The self-assembly and photophysical properties of 4-nitrophenylalanine (4NP) are changed with the alteration of solvent and final self-assembly state of 4NP in competitive solvent mixture and are dictated by the solvent ratio.

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