scholarly journals Studies on recording magnetic materials and magnetic composites. XXI. How the molecular weight of polymers having carboxyl groups influences their adsorption onto magnetic particles.

1989 ◽  
Vol 46 (6) ◽  
pp. 335-340
Author(s):  
Katsuhiko NAKAMAE ◽  
Shusaku NAKANO ◽  
Satoshi TANIGAWA
Keyword(s):  
Molecular Weight ◽  
Magnetic Materials ◽  
Magnetic Particles ◽  
Carboxyl Groups ◽  
Magnetic Composites

STRUCTURE ACTIVITY RELATIONSHIPS OF DERMATAN SULFATE : EFFECT OF MOLECULAR SIZE AND CARBOXYL GROUP ESTERIFICATION ON HEPARIN C0FACT0R-II ACTIVATION

1987 ◽  
Author(s):  
J Mardiguian ◽  
M Corgier ◽  
M Jouany
Keyword(s):  
Molecular Weight ◽  
Dermatan Sulfate ◽  
Methyl Esters ◽  
Molecular Size ◽  
Carboxyl Groups ◽  
Gel Chromatography ◽  
Carboxyl Group ◽  
Heparin Cofactor Ii ◽  
High Affinity

Dermatan is a high molecular weight glycosaminoglycan which has been shown to enhance the inhibition of thrombin by heparin-cofactor II. The aim of this study was to establish the influence of the molecular size and the role of the carboxyl group on the in vitro activity of Dermatan Sulfate. Pig skin Dermatan Sulfate was fractionated according to molecular size by gel-chromatography on Ultrogel Ac 44. Each fraction was characterized by its sulfur content and by its mean molecular weight measured on a TSK - 4000 column in reference to standard heparin fractions. Methyl esters of the unfractionated Dermatan Sulfate with varying degree of esterification, where prepared via activation of the carboxyl groups with a carbodiimide and reaction with methanol. The results of this study show that the heparin - cofactor II mediated anti-thrombin activity of Dermatan Sulfate is increasing with the molecular weight and is abolished by esterification of the carboxyl groups. Moreover, it can be speculated that each fraction contains the same amount of high affinity fraction and that, like heparin, the potency of the high affinity component is increasing with the molecular weight.

scholarly journals Carbopol 71G-NF polymer –The next pillar of oral solid dosage form

2020 ◽  
Vol 1 (1) ◽  
pp. 010-017
Author(s):  
R. Priyanka ◽  
R. Senthil Prabhu
Keyword(s):  
Molecular Weight ◽  
Drug Release ◽  
Acrylic Acid ◽  
High Molecular Weight ◽  
Dosage Form ◽  
Carboxyl Groups ◽  
Dry Powders ◽  
Solid Dosage Form ◽  
Solid Dosage ◽  
Pharmaceutical Application

For pharmaceutical Oral Solid Dosage Form (OSDF) there are lots of excipients used and these excipients influence the drug release. In the recent decades there has been considerable interest in using carbopol polymers as excipients in a distinctive range of pharmaceutical application. Carbopol polymers are high molecular weight, cross linked, acrylic, acid-based polymers. Carbopol homopolymers are polymers of acrylic acid cross linked with ally sucrose or allylPentaerythritol. These polymers are offered as fluffy, white, dry powders. The carboxyl groups provided by the acrylic acid backbone of the polymer are responsible for many of the product benefits. This review work aims at guesstimate the characteristic of Carbopol 71G-NF polymer to be used as excipients in oral solid dosage form (OSDF).

scholarly journals Recent Advances in Metal-Based Magnetic Composites as High-Efficiency Candidates for Ultrasound-Assisted Effects in Cancer Therapy

2021 ◽  
Vol 22 (19) ◽  
pp. 10461
Author(s):  
Zhenyu Wang ◽  
Xiaoxiao He ◽  
Shiyue Chen ◽  
Chengdian He ◽  
Teng Wang ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Cancer Cells ◽  
Magnetic Materials ◽  
High Efficiency ◽  
Structural Information ◽  
Drug Loading ◽  
Biological Tissues ◽  
Tissue Imaging ◽  
Mechanical Stimuli ◽  
Magnetic Composites

Metal-based magnetic materials have been used in different fields due to their particular physical or chemical properties. The original magnetic properties can be influenced by the composition of constituent metals. As utilized in different application fields, such as imaging monitoring, thermal treatment, and combined integration in cancer therapies, fabricated metal-based magnetic materials can be doped with target metal elements in research. Furthermore, there is one possible new trend in human activities and basic cancer treatment. As has appeared in characterizations such as magnetic resonance, catalytic performance, thermal efficiency, etc., structural information about the real morphology, size distribution, and composition play important roles in its further applications. In cancer studies, metal-based magnetic materials are considered one appropriate material because of their ability to penetrate biological tissues, interact with cellular components, and induce noxious effects. The disruptions of cytoskeletons, membranes, and the generation of reactive oxygen species (ROS) further influence the efficiency of metal-based magnetic materials in related applications. While combining with cancer cells, these magnetic materials are not only applied in imaging monitoring focus areas but also could give the exact area information in the cure process while integrating ultrasound treatment. Here, we provide an overview of metal-based magnetic materials of various types and then their real applications in the magnetic resonance imaging (MRI) field and cancer cell treatments. We will demonstrate advancements in using ultrasound fields co-worked with MRI or ROS approaches. Besides iron oxides, there is a super-family of heterogeneous magnetic materials used as magnetic agents, imaging materials, catalytic candidates in cell signaling and tissue imaging, and the expression of cancer cells and their high sensitivity to chemical, thermal, and mechanical stimuli. On the other hand, the interactions between magnetic candidates and cancer tissues may be used in drug delivery systems. The materials’ surface structure characteristics are introduced as drug loading substrates as much as possible. We emphasize that further research is required to fully characterize the mechanisms of underlying ultrasounds induced together, and their appropriate relevance for materials toxicology and biomedical applications.

scholarly journals Magnetic Particles: Their Applications from Sample Preparations to Biosensing Platforms

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 302 ◽  
Author(s):  
Seong-Eun Kim ◽  
My Van Tieu ◽  
Sei Young Hwang ◽  
Min-Ho Lee
Keyword(s):  
Iron Oxide ◽  
Magnetic Materials ◽  
Magnetic Particles ◽  
Ease Of Use ◽  
Iron Oxide Particles ◽  
Scientific Publications ◽  
Magnetic Iron Oxide ◽  
Automation Systems ◽  
Target Molecules ◽  
Oxide Particles

The growing interest in magnetic materials as a universal tool has been shown by an increasing number of scientific publications regarding magnetic materials and its various applications. Substantial progress has been recently made on the synthesis of magnetic iron oxide particles in terms of size, chemical composition, and surface chemistry. In addition, surface layers of polymers, silica, biomolecules, etc., on magnetic particles, can be modified to obtain affinity to target molecules. The developed magnetic iron oxide particles have been significantly utilized for diagnostic applications, such as sample preparations and biosensing platforms, leading to the selectivity and sensitivity against target molecules and the ease of use in the sensing systems. For the process of sample preparations, the magnetic particles do assist in target isolation from biological environments, having non-specific molecules and undesired molecules. Moreover, the magnetic particles can be easily applied for various methods of biosensing devices, such as optical, electrochemical, and magnetic phenomena-based methods, and also any methods combined with microfluidic systems. Here we review the utilization of magnetic materials in the isolation/preconcentration of various molecules and cells, and their use in various techniques for diagnostic biosensors that may greatly contribute to future innovation in point-of-care and high-throughput automation systems.

Oil organogel system for magnetorheological fluid

RSC Advances ◽  
2016 ◽  
Vol 6 (114) ◽  
pp. 113463-113468 ◽  
Author(s):  
Jianjian Yang ◽  
Hua Yan ◽  
Hansong Zhang ◽  
Xuemei Wang
Keyword(s):  
Molecular Weight ◽  
Magnetic Particles ◽  
Magnetorheological Fluid ◽  
Low Molecular Weight ◽  
New Approach ◽  
Low Molecular Weight Gelator

A new approach to dispersing magnetic particles via an oil organogel formed by a low molecular weight gelator to prepare MRF.

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