scholarly journals Morphological Estimation of DMPC/DHPC Self-Assemblies in Diluted Condition: Based on Physicochemical Membrane Properties

2018 ◽  
Author(s):  
Shogo Taguchi ◽  
Keishi Suga ◽  
Keita Hayashi ◽  
Yukihiro Okamoto ◽  
Hidemi Nakamura ◽  
...  
Keyword(s):  
Phase Transition ◽  
Self Assembly ◽  
The Self ◽  
Membrane Properties ◽  
Fluorescence Probes ◽  
Molar Ratio ◽  
Lipid Concentration ◽  
Total Lipid Concentration ◽  
Gel Phase ◽  
Ordered State

Self-assembly membranes, composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC), were characterized at the total lipid concentration below 20 mM. The sizes of the assemblies varied depending on the molar ratio of DMPC and DHPC (q = [DMPC]/[DHPC]). The small assemblies with diameter of ca. 10 nm were formed at q ≤ 2.0 at 20 ºC (below phase transition temperature of DMPC). The physicochemical membrane properties were then studied using fluorescence probes, 1,6-diphenyl-1,3,5-hexatriene and 6-dodecanoyl-N,N-dimethyl-2-naphthylamine, upon the dilution. DHPC micelle showed a higher membrane fluidity, while the DMPC/DHPC membranes at q ≥ 0.5 showed lower membrane fluidities as well as DMPC vesicle in gel (ordered) phase. Upon dilution, the ordered membrane properties were maintained while the solution turbidities increased, implying the morphological change of the self-assembly, bicelle to the vesicle in gel phase. Based on the obtained results, a phase diagram of DMPC/DHPC binary system (at 20 ºC) is described: (i) the bicelle suspension is transparent and the membrane is in ordered state, (ii) the micelle suspension is transparent and the membrane is in disordered state, (iii) the vesicle suspension is turbid and the membrane is in ordered state.

scholarly journals 2-Deoxyglucose-Modified Folate Derivative: Self-Assembling Nanoparticle Able to Load Cisplatin

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1084 ◽  
Author(s):  
Shaoming Jin ◽  
Zhongyao Du ◽  
Pengjie Wang ◽  
Huiyuan Guo ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Folic Acid ◽  
Self Assembly ◽  
Water Solubility ◽  
Pure Water ◽  
The Self ◽  
Molar Ratio ◽  
Antineoplastic Drugs ◽  
Self Assembling ◽  
Bonding Interaction ◽  
Nano Drug Delivery

Folic acid has been widely introduced into nano-drug delivery systems to give nanoparticle-targeted characteristics. However, the poor water solubility of folic acid may hinder the exploitation of its ability to load antineoplastic drugs. In the present study, we designed a new folate derivative (FA-2-DG) synthesized from folic acid and 2-Deoxyglucose (2-DG). The aim of this study was to evaluate the self-assembly characteristics of FA-2-DG, and its ability of loading cisplatin. The critical micelle concentration was 7.94 × 10−6 mol L−1. Fourier transform infrared spectroscopy indicated that hydrogen bonding interaction is a main driving force for the self–assembly of FA-2-DG. The particle was stable in pure water or 0.5% bovine serum albumin dispersions. By forming a coordination bond, the particles assembled from FA-2-DG can load cisplatin. The loading efficiency was maximal when the molar ratio of FA-2-DG to cisplatin was 2:1.

Biodegradable poly(ethylene glycol)–poly(ε-carprolactone) polymeric micelles with different tailored topological amphiphilies for doxorubicin (DOX) drug delivery

RSC Advances ◽  
2016 ◽  
Vol 6 (63) ◽  
pp. 58160-58172 ◽  
Author(s):  
Y. Chen ◽  
Y. X. Zhang ◽  
Z. F. Wu ◽  
X. Y. Peng ◽  
T. Su ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Ethylene Glycol ◽  
Self Assembly ◽  
Polymeric Micelles ◽  
The Self ◽  
Molar Ratio ◽  
Poly Ethylene Glycol ◽  
Biodegradable Poly ◽  
Poly Ethylene

The self-assembly and drug release of the three PEG–PCL copolymers with different topologies but identical molar ratio between PEG to PCL.

Probing Ethanol-Induced Phospholipid Phase Transitions by the Polarity Sensitive Fluorescence Probes Prodan and Patman

2002 ◽  
Vol 216 (3) ◽  
Author(s):  
R. Hutterer ◽  
M. Hof
Keyword(s):  
Phase Transition ◽  
Emission Spectra ◽  
Fluorescence Probes ◽  
Lipid Phase ◽  
Time Resolved ◽  
Pronounced Increase ◽  
Spectral Shifts ◽  
Gel Phase ◽  
Polarity Sensitive ◽  
Specific Lipid

The emission behaviour of the two polarity sensitive probes Prodan and Patman in phospholipid vesicles was studied as a function of the concentration of ethanol. Comparing the spectral shifts in both the symmetric lipid 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) showing a phase transition from a normal to a fully interdigitated gel phase and the strongly asymmetric lipid 1-stearoyl-2-lauroyl-sn-glycero-3-phosphatidylcholine (C(18):C(12)-PC) favouring a mixed interdigitated gel phase we show that the huge red shifts of Prodan in presence of higher ethanol concentrations cannot be easily attributed to a specific lipid phase transition. Rather, probe relocation and a pronounced increase in solvent relaxation (SR) as monitored by time-resolved emission spectra (TRES) in presence of ethanol contribute to the large shifts observable in both lipid systems in case of Prodan. While Patman exhibits a red shift caused by increased SR due to the ethanol induced formation of a fully interdigitated phase in DPPC, hardly any shift occurs in C(18):C(12)-PC, which is supposed not to undergo an ethanol-induced phase transition.

scholarly journals Systematic Characterization of DMPC/DHPC Self-Assemblies and Their Phase Behaviors in Aqueous Solution

2018 ◽  
Vol 2 (4) ◽  
pp. 73 ◽  
Author(s):  
Shogo Taguchi ◽  
Keishi Suga ◽  
Keita Hayashi ◽  
Yukihiro Okamoto ◽  
Ho-Sup Jung ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Membrane Properties ◽  
Morphological Properties ◽  
Molar Ratio ◽  
Region I ◽  
Gel Phase ◽  
Phase Behaviors ◽  
Region Ii ◽  
Interfacial Membrane

Self-assemblies composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) form several kinds of structures, such as vesicle, micelle, and bicelle. Their morphological properties have been studied widely, but their interfacial membrane properties have not been adequately investigated. Herein, we report a systematic characterization of DMPC/DHPC assemblies at 20 °C. To investigate the phase behavior, optical density OD500, size (by dynamic light scattering), membrane fluidity 1/PDPH (using 1,6-diphenyl-1,3,5-hexatriene), and membrane polarity GP340 (using 6-dodecanoyl-N,N-dimethyl-2-naphthylamine) were measured as a function of molar ratio of DHPC (XDHPC). Based on structural properties (OD500 and size), large and small assemblies were categorized into Region (i) (XDHPC < 0.4) and Region (ii) (XDHPC ≥ 0.4), respectively. The DMPC/DHPC assemblies with 0.33 ≤ XDHPC ≤ 0.67 (Region (ii-1)) showed gel-phase-like interfacial membrane properties, whereas DHPC-rich assemblies (XDHPC ≥ 0.77) showed disordered membrane properties (Region (ii-2)). Considering the structural and interfacial membrane properties, the DMPC/DHPC assemblies in Regions (i), (ii-1), and (ii-2) can be determined to be vesicle, bicelle, and micelle, respectively.

Self-Assembly of a Modular Polypeptide based on Blocks of Silk-Mimetic and ElastinMimetic Sequences

2002 ◽  
Vol 724 ◽  
Author(s):  
Chrystelle S. Cazalis ◽  
Vincent P. Conticello
Keyword(s):  
Phase Transition ◽  
Self Assembly ◽  
Silk Fiber ◽  
The Self ◽  
Gene Encoding ◽  
Dragline Silk ◽  
Spider Dragline Silk ◽  
E Coli ◽  
Irreversible Aggregation ◽  
Α Helix

AbstractSpider dragline silk fiber displays a unique and technologically significant combination of high tensile and compressive strength. The structural origin of these properties arises from the alternating sequence of crystalline alanine-rich domains and amorphous glycine-rich domains, which undergo microscopic phase separation in the silk fiber. We previously reported the synthesis and the self-assembly of a novel polypeptide 1, which emulates the modular structure of crystalline and amorphous elastomeric domains in dragline silk proteins. The sequence of this polypeptide comprises an alternating arrangement of a self-complementary, amphiphilic silk-mimetic oligopeptide (Ala-Glu-Ala-Glu-Ala-Lys-Ala-Lys) and environmentally-responsive elastin-mimetic segment (Val-Pro-Gly-Val-Gly). We report herein the synthesis and the self-assembly of an analogous polypeptide (2) with an higher content of elastin mimetic pentapeptides. A synthetic gene encoding four repeats of the alternating sequence was expressed in E. coli strain BL21(DE3) as a C-terminal fusion to a decahistidine leader sequence to afford a polypeptide with a molar mass of approximately 39 kDa. The regularly alternating pattern of elastin-mimetic and silk-mimetic blocks within the protein allowed the copolymer to spontaneously self-assemble upon heating above the phase transition of the elastin-mimetic block. The self-assembly process was studied using a combination of CD and solid-state NMR spectroscopy, which suggested that the alanine-rich domains undergo a conformational rearrangement from α-helix to β-sheet. This rearrangement coincides with the macromolecular phase transition of the elastin-mimetic domains, which resulted in irreversible aggregation of the polypeptide above the Tt of the elastin-mimetic domains.

Solvent–gelator interactions—using empirical solvent parameters to better understand the self-assembly of gel-phase materials

Soft Matter ◽  
2011 ◽  
Vol 7 (1) ◽  
pp. 110-117 ◽  
Author(s):  
William Edwards ◽  
Cecile A. Lagadec ◽  
David K. Smith
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Solvent Parameters ◽  
Gel Phase

Impact of the molar ratio and the nature of the counter-ion on the self-assembly of myristic acid

2018 ◽  
Vol 510 ◽  
pp. 133-141 ◽  
Author(s):  
Audrey Arnould ◽  
Fabrice Cousin ◽  
Léa Chabas ◽  
Anne-Laure Fameau
Keyword(s):  
Self Assembly ◽  
Myristic Acid ◽  
The Self ◽  
Molar Ratio ◽  
Counter Ion

Efficient synthesis and self-assembly of hetero-grafted amphiphilic polypepide bottlebrushes

2012 ◽  
Vol 84 (12) ◽  
pp. 2569-2578 ◽  
Author(s):  
Chunhui Luo ◽  
Chongyi Chen ◽  
Zhibo Li
Keyword(s):  
Self Assembly ◽  
Ring Opening ◽  
Click Reaction ◽  
Ring Opening Polymerization ◽  
The Self ◽  
Molar Ratio ◽  
Efficient Synthesis ◽  
Poly Ethylene Glycol ◽  
New Type ◽  
Poly Ethylene

A new type of hetero-grafted molecular bottlebrush with polypeptide as backbone was synthesized using graft-onto strategy. Poly(γ-propargyl-L-glutamate) (PPLG) as backbone was firstly synthesized via ring-opening polymerization (ROP) of γ-propargyl-L-glutamate (PLG) N-carboxyanhydride (NCA). Next, polystyrene-N3 (PS-N3) and monomethoxy poly(ethylene glycol)-N3 (mPEG-N3) as side chains were grafted onto the PPLG backbone using copper-catalyzed click reaction, which afforded good grafting density and efficiency. Two polypeptide bottlebrushes with PS-to-mPEG molar ratio at 70/30 and 30/70 were prepared. The self-assembly behaviors of these two polypeptide bottlebrushes were investigated using the cosolvent method, and their supramolecular structures were characterized using light scattering (LS) and electron microscopy.

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