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Progress in Biophysics and Molecular... Oct 2022It has previously been hypothesized that consciousness is the aggregate of our evolutionary history, forged by ontogeny and phylogeny via cell-cell communications. In an...
It has previously been hypothesized that consciousness is the aggregate of our evolutionary history, forged by ontogeny and phylogeny via cell-cell communications. In an on-going effort to identify the serial pre-adaptations that gave rise to consciousness, certain fundamental properties of the emerging cell are addressed herein. Evolution is topologic because it began as a phase transition caused by gravity attracting lipid molecules, spontaneously forming micelles submersed in the ocean that covered the primordial Earth, forming a surface boundary between the exterior Cosmos and the interior of micelles. Such protocells comply with the First Principles of Physiology-negative entropy, chemiosmosis and homeostasis-the first two principles being deterministic, the last being probabilistic, bestowing them with far more than just random chance. The mechanism of cellular evolution is based on exaptations of sequentially earlier and earlier genetic traits, working in reverse from present-day physiology all the way back to the unicellular state, which is homologous with mathematical 'knots'. Ironically, that relationship is evidence for the ontologic and epistemologic primacy of the cell, which supersedes mathematics and physics as manifestations of the Implicate Order since a conscious cell can conceive of a circle, but an unconscious circle is not able to conceive of a cell.
Topics: Biological Evolution; Consciousness; Homeostasis; Micelles; Phenotype; Phylogeny
PubMed: 35830897
DOI: 10.1016/j.pbiomolbio.2022.06.005 -
ACS Macro Letters Apr 2022Polymer-based gene delivery relies on the binding, protection, and final release of nucleic acid cargo using polycations. Engineering polymeric vectors, by exploring...
Polymer-based gene delivery relies on the binding, protection, and final release of nucleic acid cargo using polycations. Engineering polymeric vectors, by exploring novel topologies and cationic moieties, is a promising avenue to improve their performance, which hinges on the development of simple synthetic methods that allow facile preparation. In this work, we focus on cationic micelles formed from block polymers, which are examined as promising gene compaction agents and carriers. In this study, we report the synthesis and assembly of six amphiphilic poly(-butyl acrylate)--poly(cationic acrylamide) diblock polymers with different types of cationic groups ((dialkyl)amine, morpholine, or imidazole) in their hydrophilic corona. The polycations were obtained through the parallel postpolymerization modification of a poly(-butyl acrylate)--poly(pentafluorophenyl acrylate) reactive scaffold, which granted diblock polymers with equivalent degrees of polymerization and subsequent quantitative functionalization with cations of different p. Ultrasound-assisted direct dissolution of the polycations in different aqueous buffers (pH = 1-7) afforded micellar structures with low size dispersities and hydrodynamic radii below 100 nm. The formation and properties of micelle-DNA complexes ("micelleplexes") were explored via DLS, zeta potential, and dye-exclusion assays revealing that binding is influenced by the cation type present in the micelle corona where bulkiness and p are the drivers of micelleplex formation. Combining parallel synthesis strategies with simple direct dissolution formulation opens opportunities to optimize and expand the range of micelle delivery vehicles available by facile tuning of the composition of the cationic micelle corona.
Topics: Cations; Gene Transfer Techniques; Micelles; Plasmids; Polymers
PubMed: 35575319
DOI: 10.1021/acsmacrolett.2c00015 -
Drug Delivery and Translational Research Nov 2023Among various nanocarriers, liposomes, and micelles are relatively mature drug delivery systems with the advantages of prolonging drug half-life, reducing toxicity, and... (Review)
Review
Among various nanocarriers, liposomes, and micelles are relatively mature drug delivery systems with the advantages of prolonging drug half-life, reducing toxicity, and improving efficacy. However, both have problems, such as poor stability and insufficient targeting. To further exploit the excellent properties of micelles and liposomes and avoid their shortcomings, researchers have developed new drug delivery systems by combining the two and making use of their respective advantages to achieve the goals of increasing the drug loading capacity, multiple targeting, and multiple drug delivery. The results have demonstrated that this new combination approach is a very promising delivery platform. In this paper, we review the combination strategies, preparation methods, and applications of micelles and liposomes to introduce the research progress, advantages, and challenges of composite carriers.
Topics: Liposomes; Micelles; Drug Carriers; Drug Delivery Systems
PubMed: 37278964
DOI: 10.1007/s13346-023-01368-x -
International Journal of Molecular... Nov 2022AQEE-30 is one of the VGF peptides, which are derived from the VGF polypeptide precursor, and related to various physiological phenomena including neuroprotective...
AQEE-30 is one of the VGF peptides, which are derived from the VGF polypeptide precursor, and related to various physiological phenomena including neuroprotective effects in Huntington's disease and amyotrophic lateral sclerosis (ALS). Although various functions of AQEE-30 have been reported so far, the structure of this peptide has not been reported yet. In this study, the structure of human AQEE-30 was investigated in hexafluoroisopropanol (HFIP) and dodecyl phosphocholine (DPC) micelle solutions, using circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy. CD results showed that AQEE-30 had a partial helical structure in aqueous buffer, and the helical structure was stabilized in the HFIP and DPC micelle solutions. The 3D structures determined by NMR spectroscopy showed that AQEE-30 adopted mainly α-helical structure in both the HFIP and DPC micelle solutions. The surface of AQEE-30 showed that it was predominantly negatively charged. The residues from 601 to 611 in both the HFIP and DPC micelle solutions showed amphiphilicity with four negatively charged residues, glutamate. The C-terminal consecutive arginine residues formed a partial positively charged surface. These results suggest an α-helical active structure of AQEE-30 in the cell-membrane environment.
Topics: Humans; Micelles; Neuropeptides; Circular Dichroism; Membranes; Peptides; Nerve Growth Factors
PubMed: 36430431
DOI: 10.3390/ijms232213953 -
Langmuir : the ACS Journal of Surfaces... Oct 2021Self-assembled wormlike micelles (WLMs) are widely studied in small-molecule surfactants due to their unique ability to break and recombine; however, less is known about...
Self-assembled wormlike micelles (WLMs) are widely studied in small-molecule surfactants due to their unique ability to break and recombine; however, less is known about the structure and dynamics of nonionic polymer WLMs. Here, solutions of seven triblock poloxamers, composed of poly(propylene oxide) (PPO) midblocks and poly(ethylene oxide) (PEO) end blocks, are comprehensively examined to determine the role of poloxamer composition, temperature, and inorganic salt type and concentration on rod formation and subsequent elongation into WLMs. Phase separation and sphere-to-rod transition temperatures were quantified via cloud point measurements and shear rheology, respectively, and corroborated with small-angle neutron scattering (SANS). The local microstructure of resulting rodlike micelles is remarkably similar across poloxamer type and sodium fluoride (NaF) or sodium chloride (NaCl) content. Salt addition reduces transition temperatures, with the most pronounced effects for poloxamers with high PEO molecular weights and PEO fractions. Between these two temperatures, several poloxamers elongate into WLMs, where shear rheology detects increases in viscosity up to 6 orders of magnitude. Despite similar local microstructures, poloxamer identity and salt content impact micelle growth substantially, where large poloxamers with lower PEO fractions exhibit the highest viscosities and longest relaxation times. While sodium fluoride has little impact on micelle growth, increasing NaCl concentration dramatically increases the WLM viscosity and relaxation time. This result is explained by different interactions of each salt with the micelle: whereas NaF interacts primarily with PEO chains, NaCl may also partition to the PPO/PEO interface in low levels, increasing micelle surface tension, scission energy, and contour length.
Topics: Micelles; Poloxamer; Polyethylene Glycols; Polymers; Scattering, Small Angle
PubMed: 34601878
DOI: 10.1021/acs.langmuir.1c01570 -
Journal of Colloid and Interface Science Dec 2022The critical micelle concentration, aggregation number, shape and length of spherocylindrical micelles in solutions of zwitterionic surfactants can be predicted by...
HYPOTHESIS
The critical micelle concentration, aggregation number, shape and length of spherocylindrical micelles in solutions of zwitterionic surfactants can be predicted by knowing the molecular parameters and surfactant concentrations. This can be achieved by upgrading the quantitative molecular thermodynamic model with expressions for the electrostatic interaction energy between the zwitterionic dipoles and micellar hydrophobic cores of spherical and cylindrical shapes.
THEORY
The correct prediction of the mean micellar aggregation numbers requires precise calculations of the free energy per molecule in the micelles. New analytical expressions for the dipole electrostatic interaction energy are derived based on the exact solutions of the electrostatic problem for a single charge close to a boundary of spherical and cylindrical dielectric media. The obtained general theory is valid for arbitrary ratios between dielectric constants, radii of spheres and cylinders, positions, and orientations of dipoles.
FINDINGS
The detailed numerical results show quantitatively the effects of the micelle curvature and dielectric properties of the continuum media on the decrease of the dipole electrostatic interaction energy. Excellent agreement was achieved between the theoretical predictions and experimental data for the critical micelle concentration, size and aggregation number of zwitterionic surfactant micelles. This study can be extended to mixed micelles of zwitterionic and ionic surfactants in the presence of salt to interpret and predict the synergistic effect on the rheology of solutions.
Topics: Hydrophobic and Hydrophilic Interactions; Micelles; Models, Molecular; Surface-Active Agents; Thermodynamics
PubMed: 35870400
DOI: 10.1016/j.jcis.2022.07.087 -
International Journal of Pharmaceutics Feb 2019Pluronics are triblock copolymers, in which two hydrophilic poly (ethylene oxide) (PEO) blocks are connected via a hydrophobic poly propylene oxide (PPO) block. Because... (Review)
Review
Pluronics are triblock copolymers, in which two hydrophilic poly (ethylene oxide) (PEO) blocks are connected via a hydrophobic poly propylene oxide (PPO) block. Because of their low molecular weight and high content of PEO, Pluronics have demonstrated the micellization phenomenon, which is dependent on temperature and/or concentration. With an understanding of micellization phenomenon in more detail, information on the morphology, micelle core radius, aggregation behavior with critical micelle concentration (CMC) and critical micelle temperature (CMT) and so on has been revealed. Based on this acquired information, various studies have been performed for biomedical applications such as drug delivery systems, tissue regeneration scaffolders, and biosurfactants. This review discusses the delivery of small molecules and macromolecules using Pluronic-based NPs and their composites.
Topics: Animals; Antineoplastic Agents; Drug Delivery Systems; Humans; Micelles; Molecular Imaging; Molecular Weight; Nanoparticles; Neoplasms; Poloxamer; Surface-Active Agents; Temperature
PubMed: 30529667
DOI: 10.1016/j.ijpharm.2018.11.064 -
Journal of Drug Targeting Aug 2014In this review, polymeric micelles as drug-targeting carriers are concisely explained. In the first introduction part, I describe a brief history of polymer micelle's... (Review)
Review
In this review, polymeric micelles as drug-targeting carriers are concisely explained. In the first introduction part, I describe a brief history of polymer micelle's research for drug targeting, and then I explain this review's focus. Since most other review articles concerning polymeric micelle carriers explain only what was achieved in the polymeric micelle's research, I describe this review by focusing on what was not done. In the second part, I take up three characteristics of polymeric micelle carriers by comparing their advantages and disadvantages, what was done and what was not done in the past studies, and what is easily achieved and what is difficult to be achieved with polymeric micelles. In the last part, I discuss three common problems of nano-sized drug carrier systems including polymeric micelles, and then I add a few comments on these problems.
Topics: Animals; Drug Carriers; Drug Compounding; Drug Liberation; Drug Stability; Humans; Micelles; Particle Size; Pharmaceutical Preparations; Polymers; Surface Properties; Tissue Distribution
PubMed: 25012065
DOI: 10.3109/1061186X.2014.934688 -
Angewandte Chemie (International Ed. in... Mar 2016The N-terminal SH3 domain of the Drosophila signal transduction protein drk was encapsulated in reverse micelles. Both the temperature of maximum stability and the...
The N-terminal SH3 domain of the Drosophila signal transduction protein drk was encapsulated in reverse micelles. Both the temperature of maximum stability and the melting temperature decreased on encapsulation. Dissecting the temperature-dependent stability into enthalpic and entropic contributions reveals a stabilizing enthalpic and a destabilizing entropic contribution. These results do not match the expectations of hard-core excluded volume theory, nor can they be wholly explained by interactions between the head groups in the reverse micelle and the test protein. We suggest that geometric constraints imposed by the reverse micelles need to be considered.
Topics: Micelles; Protein Stability; Proteins
PubMed: 26854977
DOI: 10.1002/anie.201508981 -
Chemistry and Physics of Lipids Mar 2024The proportion of sodium taurolithocholate (NaTLC) is extremely low in human bile salts. NaTLC forms aggregates with other lipids in the bile and functions as an...
The proportion of sodium taurolithocholate (NaTLC) is extremely low in human bile salts. NaTLC forms aggregates with other lipids in the bile and functions as an emulsifying and solubilizing agent. The molecular structure of NaTLC contains hydrophilic hydroxyl and sulfonic acid groups at both ends of the steroid ring. This molecular structure is similar to bolaform amphiphilic substance having hydrophilic groups at both ends due to the characteristics of its molecular structure. This study investigated the aggregate properties of the NaTLC using surface tension measurements, light scattering, small-angle X-ray scattering (SAXS), and cryo-transmission electron microscopy (cryo-TEM). Surface tension measurement showed that the surface tension of the NaTLC solution decreased to 54 mN m. The concentration that showed the minimum surface tension corresponded to the critical micelle concentration (CMC: 0.6 mmol L, 308 K) determined by the change in light scattering intensity. On the other hand, the degree of counterion (sodium ions) binding to the micelles increased with increasing NaTLC concentration. SAXS and cryo-TEM measurements showed that the NaTLC formed large string-like micelles. The surface activity and large aggregates showed the potential for use as biosurfactants. However, because of the relatively low solubility of NaTLC in water, its use as a biosurfactant is limited to a narrow concentration range.
Topics: Humans; Micelles; Taurolithocholic Acid; Sodium; Scattering, Small Angle; X-Ray Diffraction
PubMed: 38325711
DOI: 10.1016/j.chemphyslip.2024.105378