Self Assembling Nanostructured Delivery Vehicles for Biochemically Reactive Pairs

1994 ◽  
Vol 351 ◽  
Author(s):  
Nir Kossovsky ◽  
A. Gelman ◽  
H.J. Hnatyszyn ◽  
E. Sponsler ◽  
G.-M. Chow
Keyword(s):  
Physical Properties ◽  
Self Assembly ◽  
Materials Science ◽  
Technology Development ◽  
Biological Behavior ◽  
X Ray Diffraction ◽  
Self Assembling ◽  
Transmission Electron ◽  
Carbon Ceramic

ABSTRACTIntrigued by the deceptive simplicity and beauty of macromolecular self-assembly, our laboratory began studying models of self-assembly using solids, glasses, and colloidal substrates. These studies have defined a fundamental new colloidal material for supporting members of a biochemically reactive pair.The technology, a molecular transportation assembly, is based on preformed carbon ceramic nanoparticles and self assembled calcium-phosphate dihydrate particles to which glassy carbohydrates are then applied as a nanometer thick surface coating. This carbohydrate coated core functions as a dehydroprotectant and stabilizes surface immobilized members of a biochemically reactive pair. The final product, therefore, consists of three layers. The core is comprised of the ceramic, the second layer is the dehydroprotectant carbohydrate adhesive, and the surface layer is the biochemically reactive molecule for which delivery is desired.We have characterized many of the physical properties of this system and have evaluated the utility of this delivery technology in vitro and in animal models. Physical characterization has included standard and high resolution transmission electron microscopy, electron and x-ray diffraction and ζ potential analysis. Functional assays of the ability of the system to act as a nanoscale dehydroprotecting delivery vehicle have been performed on viral antigens, hemoglobin, and insulin. By all measures at present, the favorable physical properties and biological behavior of the molecular transportation assembly point to an exciting new interdisciplinary area of technology development in materials science, chemistry and biology.

scholarly journals Mimicking pollen and spore walls: self-assembly in action

2019 ◽  
Vol 123 (7) ◽  
pp. 1205-1218 ◽  
Author(s):  
Nina I Gabarayeva ◽  
Valentina V Grigorjeva ◽  
Alexey L Shavarda
Keyword(s):  
Self Assembly ◽  
Original Method ◽  
Pollen Grain ◽  
Periplasmic Space ◽  
Self Assembling ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Spore Walls ◽  
Pattern Determination

Abstract Background and Aims Decades of research have attempted to elucidate the underlying developmental mechanisms that give rise to the enormous diversity of pollen and spore exines. The organization of the exine starts with the establishment of an elaborate glycocalyx within which the subsequent accumulation of sporopollenin occurs. Ontogenetic studies using transmission electron microscopy of over 30 species from many different groups have shown that the sequence of structures observed during development of the exine corresponds to the sequence of self-assembling micellar mesophases (including liquid crystals) observed at increasing concentrations of surfactants. This suggested that self-assembly plays an important part in exine pattern determination. Some patterns resembling separate layers of spore and pollen grain walls have been obtained experimentally, in vitro, by self-assembly. However, to firmly establish this idea, columellate and granulate exines, the most widespread forms, needed to be simulated experimentally. Methods We used our original method, preparing mixtures of substances analogous to those known to occur in the periplasmic space of developing microspores, then leaving the mixtures undisturbed for specific periods of time to allow the process of self-assembly to occur. We developed our method further by using new substances analogous to those present in the periplasmic space and performing the experiments in a thin layer, more closely resembling the dimensions of the periplasmic space. Key Results The artificial microstructures obtained from our in vitro self-assembly experiments closely resembled the main types of exines, including tectate–columellate, granulate, alveolate and structureless, and permitted comparison with both developing and mature microspore walls. Compared with the previous attempts, we managed to simulate columellate and granulate exines, including lamellate endexine. Conclusions Our results show that simple physico-chemical interactions are able to generate patterns resembling those found in exines, supporting the idea that exine development in nature involves an interplay between the genome and self-assembly.

scholarly journals Hydroxyapatite Formation Coexists with Amyloid-like Self-Assembly of Human Amelogenin

2020 ◽  
Vol 21 (8) ◽  
pp. 2946 ◽  
Author(s):  
Jing Zhang ◽  
Jian Wang ◽  
Chengwei Ma ◽  
Junxia Lu
Keyword(s):  
Self Assembly ◽  
Tooth Enamel ◽  
Protein Assembly ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Dynamic Components ◽  
The Right

Tooth enamel is formed in an extracellular environment. Amelogenin, the major component in the protein matrix of tooth enamel during the developing stage, could assemble into high molecular weight structures, regulating enamel formation. However, the molecular structure of amelogenin protein assembly at the functional state is still elusive. In this work, we found that amelogenin is able to induce calcium phosphate minerals into hydroxyapatite (HAP) structure in vitro at pH 6.0. Assessed using X-ray diffraction (XRD) and 31P solid-state NMR (SSNMR) evidence, the formed HAP mimics natural enamel closely. The structure of amelogenin protein assembly coexisting with the HAP was also studied using atomic force microscopy (AFM), transmission electron microscopy (TEM) and XRD, indicating the β-amyloid structure of the protein. SSNMR was proven to be an important tool in detecting both the rigid and dynamic components of the protein assembly in the sample, and the core sequence 18EVLTPLKWYQSI29 was identified as the major segment contributing to the β-sheet secondary structure. Our research suggests an amyloid structure may be an important factor in controlling HAP formation at the right pH conditions with the help of other structural components in the protein assembly.

Magnetic nanostructured lipid carrier for dual triggered curcumin delivery: Preparation, characterization and toxicity evaluation on isolated rat liver mitochondria

2021 ◽  
pp. 088532822110346
Author(s):  
Mohammad Yoozbashi ◽  
Hamid Rashidzadeh ◽  
Mehraneh Kermanian ◽  
Somayeh Sadighian ◽  
Mir-Jamal Hosseini ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Nanostructured Lipid Carrier ◽  
Mitochondrial Toxicity ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Reducing Ability ◽  
Transmission Electron

In this research, magnetic nanostructured lipid carriers (Mag-NLCs) were synthesized for curcumin (CUR) delivery. NLCs are drug-delivery systems prepared by mixing solid and liquid (oil) lipids. For preparation of NLCs, cetylpalmitate was selected as solid lipid and fish oil as liquid lipid. CUR-Mag-NLCs were prepared using high-pressure homogenization technique and were characterized by methods including X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and dynamic light scattering (DLS). The CUR-Mag-NLCs were developed as a particle with a size of 140 ± 3.6 nm, a polydispersity index of 0.196, and a zeta potential of −22.6 mV. VSM analysis showed that the CUR-Mag-NLCs have excellent magnetic properties. Release rate of the drug was higher at 42 °C than 37 °C, indicating that release of the synthesized nanoparticles is temperature-dependent. Evaluation of mitochondrial toxicity was done using the isolated rats liver mitochondria including glutathione (GSH), malondialdehyde (MDA), and the ferric- reducing ability of plasma (FRAP) assays to study biosafety of the CUR-Mag-NLCs. Results of In vitro study on the isolated mitochondria revealed that both CUR-Mag-NLCs and curcumin have no specific mitochondrial toxicity.

scholarly journals Fabrication and Physical Properties of Single-Crystalline Βeta-FeSi2 Nanowires

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Chih-Yung Yang ◽  
Shu-Meng Yang ◽  
Yu-Yang Chen ◽  
Kuo-Chang Lu
Keyword(s):  
Electron Microscopy ◽  
Physical Properties ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Field Emitters ◽  
Transmission Electron ◽  
Single Source Precursor ◽  
Carrier Gases

Abstract In this study, self-catalyzed β-FeSi2 nanowires, having been wanted but seldom achieved in a furnace, were synthesized via chemical vapor deposition method where the fabrication of β-FeSi2 nanowires occurred on Si (100) substrates through the decomposition of the single-source precursor of anhydrous FeCl3 powders at 750–950 °C. We carefully varied temperatures, duration time, and the flow rates of carrier gases to control and investigate the growth of the nanowires. The morphology of the β-FeSi2 nanowires was observed with scanning electron microscopy (SEM), while the structure of them was analyzed with X-ray diffraction (XRD) and transmission electron microscopy (TEM). The growth mechanism has been proposed and the physical properties of the iron disilicide nanowires were measured as well. In terms of the magnetization of β-FeSi2, nanowires were found to be different from bulk and thin film; additionally, longer β-FeSi2 nanowires possessed better magnetic properties, showing the room-temperature ferromagnetic behavior. Field emission measurements demonstrate that β-FeSi2 nanowires can be applied in field emitters.

scholarly journals Low-temperature hydrothermal synthesis of hierarchical flower-like CuB2O4 superstructures

2020 ◽  
Vol 14 (2) ◽  
pp. 113-118
Author(s):  
Daniel Ursu ◽  
Anamaria Dabici ◽  
Marinela Miclau ◽  
Nicolae Miclau
Keyword(s):  
Thermal Stability ◽  
Low Temperature ◽  
Self Assembly ◽  
Hydrothermal Solution ◽  
Optical Measurements ◽  
Oriented Attachment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
One Step

We report for the first time the fabrication of hierarchical ordered superstructure CuB2O4 with flower-like morphology via a one-step, low temperature hydrothermal method. The tetragonal structure of CuB2O4 was determined by X-ray diffraction and high-resolution transmission electron microscopy. Optical measurements attested of the quality of the fabricated CuB2O4 and high temperature X-ray diffraction confirmed its thermal stability up to 600 ?C. The oriented attachment growth and the hierarchical self-assembly of micrometer-sized platelets producing hierarchical superstructures with flower-like morphology are designed by pH of the hydrothermal solution. The excellent band gap, high thermal stability and hierarchical structure of the CuB2O4 are promising for the photovoltaic and photocatalytic applications.

Bioinspired synthesis of self-assembled calcium phosphate nanocomposites using block copolymer-peptide conjugates

2008 ◽  
Vol 23 (12) ◽  
pp. 3196-3212 ◽  
Author(s):  
Yusuf Yusufoglu ◽  
Yanyan Hu ◽  
Mathumai Kanapathipillai ◽  
Matthew Kramer ◽  
Yunus E. Kalay ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Phosphate ◽  
Small Angle ◽  
Polymer Chains ◽  
X Ray Diffraction ◽  
X Ray ◽  
Self Assembling ◽  
Transmission Electron ◽  
Angle Scattering ◽  
Inorganic Content

Thermoreversibly gelling block copolymers conjugated to hydroxyapatite-nucleating peptides were used to template the growth of inorganic calcium phosphate in aqueous solutions. Nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), transmission electron microscopy, x-ray diffraction, and small-angle scattering were used to characterize these samples and confirm that the peptides promoted the growth of hydroxyapatite as the inorganic phase. Three different polymer templates were used with varying charges on the polymer chains (nonionic, anionic, and zwitterionic), to investigate the role of charge on mineralization. All of the polymer-inorganic solutions exhibited thermoreversible gelation above room temperature. Nanocomposite formation was confirmed by solid-state NMR, and several methods identified the inorganic component as hydroxyapatite. Small angle x-ray scattering and electron microscopy showed thin, elongated crystallites. Thermogravimetric analysis showed an inorganic content of 30–45 wt% (based on the mass of the dried gel at ∼200 °C) in the various samples. Our work offers routes for bioinspired bottom-up approaches for the development of novel, self-assembling, injectable nanocomposite biomaterials for potential orthopedic applications.

Fe-encapsulating carbon nano onionlike fullerenes from heavy oil residue

2008 ◽  
Vol 23 (5) ◽  
pp. 1393-1397 ◽  
Author(s):  
Yongzhen Yang ◽  
Xuguang Liu ◽  
Bingshe Xu
Keyword(s):  
Electron Microscopy ◽  
Heavy Oil ◽  
Chemical Vapor ◽  
Catalyst Precursor ◽  
X Ray Diffraction ◽  
Self Assembling ◽  
Transmission Electron ◽  
Oil Residue ◽  
Heavy Oil Residue ◽  
Graphite Sheets

Fe-encapsulating carbon nano onionlike fullerenes (NOLFs) were obtained by chemical vapor deposition (CVD) using heavy oil residue as carbon source and ferrocene as catalyst precursor in an argon flow of 150 mL/min at 900 °C for 30 min. Field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive spectroscopy (EDS), x-ray diffraction (XRD), and Raman spectroscopy were used to characterize morphology and microstructure of the products. The results show that Fe-encapsulating NOLFs collected at the outlet zone of quartz tube had core/shell structures with sizes ranging from 3 to 6 nm and outer shells composed of poorly crystallized graphitic layers. Their growth followed particle self-assembling growth mechanism, and all atoms in the graphite sheets primarily arose from Fe-carbide nanoparticles.

scholarly journals On the Aqueous Solution Behavior of C-Substituted 3,1,2-Ruthenadicarbadodecaboranes

Inorganics ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 91 ◽  
Author(s):  
Marta Gozzi ◽  
Benedikt Schwarze ◽  
Peter Coburger ◽  
Evamarie Hey-Hawkins
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Self Assembly ◽  
Self Assembling ◽  
Vis Spectroscopy ◽  
Assembly Behavior ◽  
Biological Performance ◽  
Type 3

3,1,2-Ruthenadicarbadodecaborane complexes bearing the [C2B9H11]2− (dicarbollide) ligand are robust scaffolds, with exceptional thermal and chemical stability. Our previous work has shown that these complexes possess promising anti-tumor activities in vitro, and tend to form aggregates (or self-assemblies) in aqueous solutions. Here, we report on the synthesis and characterization of four ruthenium(II) complexes of the type [3-(η6-arene)-1,2-R2-3,1,2-RuC2B9H9], bearing either non-polar (R = Me (2–4)) or polar (R = CO2Me (7)) substituents at the cluster carbon atoms. The behavior in aqueous solution of complexes 2, 7 and the parent unsubstituted [3-(η6-p-cymene)-3,1,2-RuC2B9H11] (8) was investigated via UV-Vis spectroscopy, mass spectrometry and nanoparticle tracking analysis (NTA). All complexes showed spontaneous formation of self-assemblies (108–109 particles mL−1), at low micromolar concentration, with high polydispersity. For perspective applications in medicine, there is thus a strong need for further characterization of the spontaneous self-assembly behavior in aqueous solutions for the class of neutral metallacarboranes, with the ultimate scope of finding the optimal conditions for exploiting this self-assembling behavior for improved biological performance.

Synthesis and Characterization of Mesoporous Silica Nanoparticles Embedded Gadolinium Oxide

2011 ◽  
Vol 306-307 ◽  
pp. 1275-1279 ◽  
Author(s):  
Ning Qi Luo ◽  
Zhan Yun Huang ◽  
Ping Luo ◽  
Yuan Zhi Shao ◽  
Di Hu Chen
Keyword(s):  
Mesoporous Silica ◽  
Self Assembly ◽  
Mesoporous Silica Nanoparticles ◽  
Sol Gel ◽  
Mesoporous Structure ◽  
Gadolinium Oxide ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
The Mean

We first synthesized gadolinium oxide (Gd2O3) by a modified “polyol” strategy and then embedded it into mesoporous silica by a simple self-assembly sol-gel reaction. Scanning electron microscope (SEM) results show that the samples have good sphericity and good dispersibility. The structure of mesoporous silica was characterized by transmission electron microscopy (TEM) and small-angle X-ray diffraction (SAXRD). Results show that the mesoporous structure has not been destroyed after gadolinium oxide imbedding. The ratio of gadolinium and silica was determined by the mean of energy dispersive spectroscopy (EDS).

scholarly journals Virus assembly occurs following a pH- or Ca 2+ -triggered switch in the thermodynamic attraction between structural protein capsomeres

2009 ◽  
Vol 7 (44) ◽  
pp. 409-421 ◽  
Author(s):  
Yap P. Chuan ◽  
Yuan Y. Fan ◽  
Linda H. L. Lua ◽  
Anton P. J. Middelberg
Keyword(s):  
Self Assembly ◽  
Virus Assembly ◽  
Chemical Change ◽  
Second Virial Coefficient ◽  
Direct Proof ◽  
Viral Assembly ◽  
Structural Protein ◽  
Salting Out ◽  
Self Assembling

Viral self-assembly is of tremendous virological and biomedical importance. Although theoretical and crystallographic considerations suggest that controlled conformational change is a fundamental regulatory mechanism in viral assembly, direct proof that switching alters the thermodynamic attraction of self-assembling components has not been provided. Using the VP1 protein of polyomavirus, we report a new method to quantitatively measure molecular interactions under conditions of rapid protein self-assembly. We show, for the first time, that triggering virus capsid assembly through biologically relevant changes in Ca 2+ concentration, or pH, is associated with a dramatic increase in the strength of protein molecular attraction as quantified by the second virial coefficient ( B 22 ). B 22 decreases from −2.3 × 10 −4 mol ml g −2 (weak protein–protein attraction) to −2.4 × 10 −3 mol ml g −2 (strong protein attraction) for metastable and Ca 2+ -triggered self-assembling capsomeres, respectively. An assembly-deficient mutant (VP1CΔ63) is conversely characterized by weak protein–protein repulsion independently of chemical change sufficient to cause VP1 assembly. Concomitant switching of both VP1 assembly and thermodynamic attraction was also achieved by in vitro changes in ammonium sulphate concentration, consistent with protein salting-out behaviour. The methods and findings reported here provide new insight into viral assembly, potentially facilitating the development of new antivirals and vaccines, and will open the way to a more fundamental physico-chemical description of complex protein self-assembly systems.

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