Colorimetric and dynamic light scattering detection of DNA sequences by using positively charged gold nanospheres: a comparative study with gold nanorods

The formation and dimensions of G-wires by different short G-rich DNA sequences in solution were investigated by dynamic light scattering (DLS) and polyacrilamide gel electrophoresis (PAGE). To explore the basic principles of wire formation, we studied the effects of base sequence, method of preparation, temperature, and oligonucleotide concentration. Both DLS and PAGE show that thermal annealing induces much less macromolecular self-assembly than dialysis. The degree of assembly and consequently length of G-wires (5-6 nm) are well resolved by both methods for DNA sequences with intermediate length, while some discrepancies appear for the shortest and longest sequences. As expected, the longest DNA sequence gives the longest macromolecular aggregates with a length of about 11 nm as estimated by DLS. The quadruplex topologies show no concentration dependence in the investigated DNA concentration range (0.1 mM–0.4 mM) and no structural change upon heating.

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New long-term action insulin formulations obtained using polycations for heparin neutralization

Bio-Algorithms and Med-Systems ◽

10.1515/bams-2019-0029 ◽

2019 ◽

Vol 15 (3) ◽

Cited By ~ 1

Author(s):

Kamil Kamiński ◽

Marta Kaczor-Kamińska ◽

Izabela Irska ◽

Iwona Popiołek ◽

Krzysztof Szczubiałka ◽

...

Keyword(s):

Light Scattering ◽

Dynamic Light Scattering ◽

Anticoagulant Activity ◽

Fluorescence Measurements ◽

Charged Polymers ◽

Acting Insulin ◽

Long Acting ◽

Heparin Neutralization ◽

Positively Charged

AbstractPhenomena that occur between an insulin and four different positively charged polymers (protamine, cationic dextran, chitosan, and poliallylamine derivatives) were studied by dynamic light scattering and fluorescence measurements (using fluorescein-labeled polymers). These processes were compared to the reaction of polycations with heparin that is responsible for the neutralization of anticoagulant activity in blood stream.The nature of polycations interaction with heparin is electrostatic, while the interaction with insulin is more complicated.We observed that the presence of zinc atoms (and its complexing by nitrogen from macromolecules) is critical for insulin suspensions formation and stability. The differences between the nature of these two reactions were revealed. The highly immunogenic action of protamine present in long-acting insulin products makes it reasonable to develop similar systems based on the nonprotein polycations.

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The Organic-Inorganic Complex Material Formed by {Mo154} and TTABr

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.2032 ◽

2011 ◽

Vol 236-238 ◽

pp. 2032-2035

Author(s):

Xiang Feng Jia ◽

Xing Wang Shi ◽

Yong Shan Ma

Keyword(s):

Aqueous Solution ◽

Light Scattering ◽

Dynamic Light Scattering ◽

Organic Complex ◽

Tetradecyltrimethylammonium Bromide ◽

Complex Material ◽

Inorganic Complex ◽

Simple Phase ◽

Phase Solution ◽

Positively Charged

The formation of inorganic/organic Complex Material from giant polyoxomolybdate (POM) macro-anions in solutions mixed a positively charged surfactant tetradecyltrimethylammonium bromide (TTA+Br-1) was described.surfactant tetradecyltrimethylammonium bromide (TTA+Br-1) was described. The complex can further dissolve in aqueous solution with the excess TTABr and the larger hydrophilicaggregations formed. TEM and Dynamic Light Scattering (DLS) investigations were applied to analyze the aggregations in the simple-phase solution.

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