A tensammetric study of the adsorption of cationic polymers and copolymers

1991 ◽  
Vol 69 (10) ◽  
pp. 1516-1519
Author(s):  
Truis Smith-Palmer ◽  
Cheryl Roberts
Keyword(s):  
Molecular Weight ◽  
Charge Density ◽  
Key Words ◽  
Potential Versus ◽  
Cationic Polymers ◽  
Capacitive Current ◽  
Cationic Polyacrylamide

The tensammograms of several sets of cationic polyacrylamide copolymers are discussed and compared. Tensammograms are not affected by molecular weight, but plots of capacitive current at a chosen potential versus charge density give regular curves. Key words: tensammetry, cationic, polyacrylamide, charge density.

Brushlike Cationic Polymers with Low Charge Density for Gene Delivery

2017 ◽  
Vol 19 (5) ◽  
pp. 1410-1415 ◽  
Author(s):  
Jonathan O’Keeffe Ahern ◽  
Sigen A ◽  
Dezhong Zhou ◽  
Yongsheng Gao ◽  
Jing Lyu ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Charge Density ◽  
Cationic Polymers ◽  
Low Charge

scholarly journals Polythiophenes with Cationic Phosphonium Groups as Vectors for Imaging, siRNA Delivery, and Photodynamic Therapy

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1432
Author(s):  
Laure Lichon ◽  
Clément Kotras ◽  
Bauyrzhan Myrzakhmetov ◽  
Philippe Arnoux ◽  
Morgane Daurat ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Photodynamic Therapy ◽  
Photophysical Properties ◽  
Combined Therapy ◽  
Sirna Delivery ◽  
Aqueous Media ◽  
Low Molecular Weight ◽  
Oxygen Species ◽  
Cationic Polymers ◽  
Intracellular Location

In this work, we exploit the versatile function of cationic phosphonium-conjugated polythiophenes to develop multifunctional platforms for imaging and combined therapy (siRNA delivery and photodynamic therapy). The photophysical properties (absorption, emission and light-induced generation of singlet oxygen) of these cationic polythiophenes were found to be sensitive to molecular weight. Upon light irradiation, low molecular weight cationic polythiophenes were able to light-sensitize surrounding oxygen into reactive oxygen species (ROS) while the highest were not due to its aggregation in aqueous media. These polymers are also fluorescent, allowing one to visualize their intracellular location through confocal microscopy. The most promising polymers were then used as vectors for siRNA delivery. Due to their cationic and amphipathic features, these polymers were found to effectively self-assemble with siRNA targeting the luciferase gene and deliver it in MDA-MB-231 cancer cells expressing luciferase, leading to 30–50% of the gene-silencing effect. In parallel, the photodynamic therapy (PDT) activity of these cationic polymers was restored after siRNA delivery, demonstrating their potential for combined PDT and gene therapy.

Effects of charge density and molecular weight of papermaking sludge-based flocculant on its decolorization efficiencies

2020 ◽  
Vol 723 ◽  
pp. 138136
Author(s):  
Kangying Guo ◽  
Baoyu Gao ◽  
Jingwen Pan ◽  
Xue Shen ◽  
Caiyu Liu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Charge Density

Electron Microscope Analysis of the Surface Charge of Human Platelets; Stored and Aggregated by Polymeric Bases

1975 ◽  
Author(s):  
Y. Taketomi ◽  
A. Ihara ◽  
A. Kuramoto ◽  
H. Uchino
Keyword(s):  
Molecular Weight ◽  
Sialic Acid ◽  
Plasma Membranes ◽  
Particle Density ◽  
Average Distance ◽  
Human Platelets ◽  
Degree Of Polymerization ◽  
Surface Coat ◽  
Cationic Polymers ◽  
Neuraminidase Treatment

The stainability of the surface coat of human platelets with positively charged colloidal Thorotrast was studied on the stored and aggregated platelets by some aggregating agents. During storage, the total sialic acid decreased and fell to 65% of initial value on 5th day. The sialic acid released from fresh platelets by neuraminidase treatment was 80% of the total. The density of Thorotrast particles on surface coat did not change during storage up to 7 days. These particles were abolished to some extent from the surface of neuraminidase treated platelets. These particle density did not change significantly in ADP and collagen induced aggregates but decreased in aggregates induced by cationic polymers such as protamine sulfate and polylysine. At the same concentration of polylysines of different degree of polymerization, maximal aggregation was greater with the higher molecular weight. Average distance between the plasma membranes of two adjacent cells in the aggregate was rather wider when the higher molecular weight polylysine was used.

Influence d'un préconditionnement chimique sur l'épaississement gravitaire et la déshydratation de boues d'étangs aérés facultatifs

1995 ◽  
Vol 22 (6) ◽  
pp. 1198-1216
Author(s):  
Marc-André Desjardins ◽  
Charles Bussières ◽  
François G. Brière ◽  
Danielle Dagenais
Keyword(s):  
Key Words ◽  
Capture Rate ◽  
Great Difficulty ◽  
Solid Content ◽  
Cationic Polymers ◽  
Dual Effect ◽  
Biological Sludge ◽  
Gravity Thickening ◽  
Chemical Sludge

This article presents the results of a study on the influence of chemical preconditioning on gravity thickening and dewatering of biological and chemical sludge (alum dephosphatation sludge) from facultative aerated lagoons. Four reagents have been studied: two cationic polymers and two inorganic reagents. Inorganic reagents have not improved gravity thickening of sludge while polymers were more efficient. Polymers have a dual effect: they increase capture rate and accelerate solids settling. Biological sludge from lagoons thickens easily and may reach 10 to 12% dry solid contents, with or without the addition of polymers. On the contrary, chemical sludge thickens with great difficulty. Even with the addition of polymers, the maximum dry solid content did not reach more than 3.8% for sludge with initial dry solid content of 1.25% approximately. However, higher dry solid content can be obtained if the initial dry solid content of sludge is higher. Therefore, it is important to minimize dilution during the extraction of sludge from lagoons. Finally, the addition of polymers to sludge to help thickening does not affect the reconditioning of sludge to be dewatered except possibly in the case of mechanically dewatered chemical sludge treated with chemical conditioning. Key words: chemical preconditioning, gravity thickening, dewatering, sludge, facultative aerated lagoons.

Biological Availability of Low Versus High Molecular Weight Reactive Phosphorus

1978 ◽  
Vol 35 (12) ◽  
pp. 1639-1643 ◽  
Author(s):  
Hans W. Paerl ◽  
Malcolm T. Downes
Keyword(s):  
Molecular Weight ◽  
New Zealand ◽  
Key Words ◽  
High Molecular Weight ◽  
Growth Response ◽  
Growth Yields ◽  
Good Growth ◽  
Biological Availability ◽  
Culture Filtrates ◽  
Reactive Phosphorus

When equivalent concentrations of reactive high molecular weight phosphorus (RHMW-P > 5000) and free orthophosphate (PO4-P) from Lake Tutaeinanga, New Zealand, were added to P-starved Chlorella cultures, free PO4 showed a faster growth response within 48 h than RHMW-P. Algal preference for PO4 over RHMW-P could also be shown by (32P)PO4 turnover experiments. After 96 h both fractions showed good growth yields. Analyses on culture filtrates indicated that all forms of reactive P had been removed. This demonstrates that RHMW-P, which reacts with "reactive P" reagents, can eventually be utilized. Key words: reactive phosphorus, orthophosphate, algae, Chlorella, growth, bioassay

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