Conjugates: Biosynthetic–Synthetic Polymer Based

2017 ◽  
pp. 340-361
Author(s):  
Jan C. M. van Hest
Keyword(s):  
Synthetic Polymer

Electron-diffraction studies in synthetic polymer materials

1983 ◽  
Vol 41 ◽  
pp. 362-365
Author(s):  
D.T. Grubb
Keyword(s):  
Electron Diffraction ◽  
Synthetic Polymer ◽  
Polymer Materials ◽  
Crystallographic Structure ◽  
High Dose ◽  
Electron Dose ◽  
Dose Rates ◽  
First Case ◽  
Diffraction Patterns ◽  
The Many

Diffraction studies in polymeric and other beam sensitive materials may bring to mind the many experiments where diffracted intensity has been used as a measure of the electron dose required to destroy fine structure in the TEM. But this paper is concerned with a range of cases where the diffraction pattern itself contains the important information.In the first case, electron diffraction from paraffins, degraded polyethylene and polyethylene single crystals, all the samples are highly ordered, and their crystallographic structure is well known. The diffraction patterns fade on irradiation and may also change considerably in a-spacing, increasing the unit cell volume on irradiation. The effect is large and continuous far C94H190 paraffin and for PE, while for shorter chains to C 28H58 the change is less, levelling off at high dose, Fig.l. It is also found that the change in a-spacing increases at higher dose rates and at higher irradiation temperatures.

Environmentally Friendly Preparation of Magnetic Composites Featuring Proteolytic Properties

INEOS OPEN ◽  
2020 ◽  
Author(s):  
N. A. Samoilova ◽  
Keyword(s):  
Enzyme Immobilization ◽  
Maleic Acid ◽  
Environmentally Friendly ◽  
Synthetic Polymer ◽  
Magnetic Composites ◽  
Interpolyelectrolyte Complex ◽  
Hydrolysis Rates ◽  
Poly Ethylene ◽  
Noncovalent Binding

The enzyme-containing magnetic composites are presented. The magnetic matrix for enzyme immobilization is obtained by sequential application of an amine-containing polysaccharide—chitosan and a synthetic polymer—poly(ethylene-alt-maleic acid) to the magnetite microparticles to form the interpolyelectrolyte complex shell. Then, the enzyme (trypsin) is immobilized by covalent or noncovalent binding. Thus, the suggested composites can be readily obtained in the environmentally friendly manner. The enzyme capacity of the resulting composites reaches 28.0–32.6 mg/g. The maximum hydrolysis rates of the H-Val-Leu-Lys-pNA substrate provided by these composites range within 0.60·10–7–0.77·10–7 M/min.

Successful Application of Customized Fluid Using Specialized Synthetic Polymer in High Pressured Wells to Mitigate Differential Stikcing Problems by Minimizing Pore Pressure Transmission

2014 ◽  
Author(s):  
Mohannad Sulaiman Al-Muhailan ◽  
Arun Rajagopalan ◽  
Al Aziz Khalid Al-Shayji ◽  
Prakash Balkrishna Jadhav ◽  
Faiz Ismail Khatib
Keyword(s):  
Pore Pressure ◽  
Synthetic Polymer ◽  
Pressure Transmission

Gastroretentive System of Fluvastatin Sodium by Using Natural Mucilage and Synthetic Polymer

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Umamaheswara G. ◽  
Anudeep D.
Keyword(s):  
Half Life ◽  
Release Kinetics ◽  
Kinetic Studies ◽  
Diffusion Path ◽  
Synthetic Polymer ◽  
In Vitro Dissolution ◽  
Direct Compression ◽  
Drug Content ◽  
Biological Half Life

Fluvastatin sodium is a novel compound used as cholesterol lowering agent which acts through the inhibition of 3- hydroxyl-3- methyl glutaryl- coenzyme A (HMG-Co A) reductase. It has short biological half life (1-3h) in humans required a dosing frequency of 20 to 40mg twice a day. Due to its short variable biological half life it has been developed to a sustained gastroretentive system with a natural and synthetic polymer and to study how far the natural mucilage improves the sustained activity. Floating tablets were prepared by direct compression method using in combination of natural mucilage and synthetic polymer. Prior to the preparation of tablets the physical mixtures were subjected to FT IR studies and pre compression parameters. After preparation of tablets they were subjected to various tests like swollen index, drug content, In vitro dissolution and release kinetics with pcp disso software etc. The tablets prepared by direct compression shown good in thickness, hardness and uniformity in drug content, the prepared tablets floated more than 12h except FS1 and FS2 shows 9 and 11h. Swollen index studies shows with increase in concentration of polymer the swelling increases the diffusion path length by which the drug molecule may have to travel and cause lag time. In vitro results shows that on increasing the amount of hibiscus polymer the sustain activity is increased because of its integrity and forms a thick swollen mass and reduces the erosion property of the HypromelloseK100M, kinetic studies shows that FS 1, FS2, FS3 followed the Korsmeyer peppas model and the rest FS 4, FS 5, FS6 follows the zero order respectively. Based on n value indicating that the drug release followed super case II transport mechanism due to the erosion of the polymer.

EFFICIENCY OF NEW HEMOSORBENT IN ACUTE AMITRIPTYLINE AND CYCLODOL POISONING

2020 ◽  
pp. 14-18
Author(s):  
A. M. Fomin
Keyword(s):  
Clinical Effect ◽  
High Efficiency ◽  
Initial Level ◽  
Synthetic Polymer ◽  
Complex Treatment ◽  
Direct Hemoperfusion ◽  
Selective Sorption ◽  
Positive Clinical Effect ◽  
Before And After

A complex treatment of a patient with acute amitriptyline and cyclodol poisoning using enterosorption, intestinal lavage and hemosorption on a new column with a synthetic sorbent is presented. A two-layer synthetic polymer column developed for the selective sorption of cytokines by direct hemoperfusion was used for hemosorption. Quantitative determinations of amitriptyline and cyclodol levels before and after the column, as well as before and after hemosorption have showed high efficiency of the sorbent to remove the toxicant from the blood. The use of 6-hour hemosorption allowed to reduce the level of amitriptyline from the initial level by more than 4 times and the level of cyclodol - by more than 3 times to therapeutic levels and to obtain a pronounced positive clinical effect in the complex treatment of a patient with severe poisoning.

scholarly journals Electrospun Nanofibers of Natural and Synthetic Polymers as Artificial Extracellular Matrix for Tissue Engineering

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Mina Keshvardoostchokami ◽  
Sara Seidelin Majidi ◽  
Peipei Huo ◽  
Rajan Ramachandran ◽  
Menglin Chen ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Polymer Composite ◽  
Electrospun Nanofibers ◽  
Synthetic Polymer ◽  
Inorganic Materials ◽  
Host Cells ◽  
Natural Polymer ◽  
Reinforced Polymers ◽  
Nanofibrous Scaffolds ◽  
Artificial Extracellular Matrix

Many types of polymer nanofibers have been introduced as artificial extracellular matrices. Their controllable properties, such as wettability, surface charge, transparency, elasticity, porosity and surface to volume proportion, have attracted much attention. Moreover, functionalizing polymers with other bioactive components could enable the engineering of microenvironments to host cells for regenerative medical applications. In the current brief review, we focus on the most recently cited electrospun nanofibrous polymeric scaffolds and divide them into five main categories: natural polymer-natural polymer composite, natural polymer-synthetic polymer composite, synthetic polymer-synthetic polymer composite, crosslinked polymers and reinforced polymers with inorganic materials. Then, we focus on their physiochemical, biological and mechanical features and discussed the capability and efficiency of the nanofibrous scaffolds to function as the extracellular matrix to support cellular function.

scholarly journals Synthesis and In Vitro Assessment of pH-Sensitive Human Serum Albumin Conjugates of Pirarubicin

2020 ◽  
Vol 14 (1) ◽  
pp. 22
Author(s):  
Kenji Tsukigawa ◽  
Shuhei Imoto ◽  
Keishi Yamasaki ◽  
Koji Nishi ◽  
Toshihiko Tsutsumi ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Coupling Reaction ◽  
Synthetic Polymer ◽  
Ph Sensitive ◽  
Acidic Ph ◽  
Polymer Conjugate ◽  
Acidic Conditions

In a previous study, we reported on the development of a synthetic polymer conjugate of pirarubicin (THP) that was formed via an acid-labile hydrazone bond between the polymer and the THP. However, the synthetic polymer itself was non-biodegradable, which could lead to unexpected adverse effects. Human serum albumin (HSA), which has a high biocompatibility and good biodegradability, is also a potent carrier for delivering antitumor drugs. The objective of this study was to develop pH-sensitive HSA conjugates of THP (HSA-THP), and investigate the release of THP and the cytotoxicity under acidic conditions in vitro for further clinical development. HSA-THP was synthesized by conjugating maleimide hydrazone derivatives of THP with poly-thiolated HSA using 2-iminothiolane, via a thiol-maleimide coupling reaction. We synthesized two types of HSA-THP that contained different amounts of THP (HSA-THP2 and HSA-THP4). Free THP was released from both of the HSA conjugates more rapidly at an acidic pH, and the rates of release for HSA-THP2 and HSA-THP4 were similar. Moreover, both HSA-THPs exhibited a higher cytotoxicity at acidic pH than at neutral pH, which is consistent with the effective liberation of free THP under acidic conditions. These findings suggest that these types of HSA-THPs are promising candidates for further development.

scholarly journals Vitamin E-Coated Dialyzer Inhibits Oxidative Stress

2017 ◽  
Vol 44 (4) ◽  
pp. 288-293 ◽  
Author(s):  
Shiho Yamadera ◽  
Yuya Nakamura ◽  
Masahiro Inagaki ◽  
Isao Ohsawa ◽  
Hiromichi Gotoh ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Vitamin E ◽  
Synthetic Polymer ◽  
Intracellular Reactive Oxygen Species ◽  
Ros Production ◽  
Oxygen Species ◽  
In Vitro Methods ◽  
Stress Effects ◽  
Intracellular Ros

Aim: To examine the effects of vitamin E-coated dialyzer on oxidative stress in vitro. Methods: A dialyzer with a synthetic polymer membrane (APS-11SA) and vitamin E-coated dialyzer (VPS-11SA) were connected to a blood tubing line, and U937 cells were circulated in the device. The circulating fluid was collected at 1, 2, 5, 10, 25, and 50 cycles, which are estimated numbers of passes through the dialyzer. Intracellular reactive oxygen species (ROS) production, malondialdehyde (MDA), and Cu/Zn-superoxide dismutase (SOD) were quantified. Results: Intracellular ROS production was increased in the first cycle by APS-11SA and was decreased throughout the experiment by VPS-11SA. Intracellular ROS production in the VPS-11SA device was lower, and MDA levels were decreased. MDA levels were lower during VPS-11SA processing than during APS-11SA processing. Cu/Zn-SOD levels remained unchanged. Conclusion: Our results highlight anti-oxidative-stress effects of a vitamin E-coated dialyzer.

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