scholarly journals Production, Properties and Swelling of Composite Agar-Pectic Gel Particles in an Artificial Gastroenteric Environment

2021 ◽  
Vol 11 (4) ◽  
pp. 456-459
Author(s):  
Elena Mikhailova ◽  
Anatoly Shubakov
Keyword(s):  
Molecular Weight ◽  
Aqueous Solutions ◽  
Aerial Part ◽  
Particle Density ◽  
Cross Linking ◽  
Apple Pectin ◽  
Ionotropic Gelation ◽  
Heracleum Sosnowskyi ◽  
Gel Particles

The purpose of the present work was to obtain and study the properties of composite calcium-agar-pectic gel particles (CaAPGPs) obtained from aqueous solutions of agar (AA) and apple pectin (AP), from aqueous solutions of agar (AA) and pectin heracleuman (HS) in the presence of Ca2+ ions (0.34 M). The swelling of the obtained composite CaAPGPs in an artificial gastroenteric environment was also investigated. Methods and Results: We used commercial AP AU701 (AP, Herbstreith & Fox KG, Germany), HS isolated from the aerial part of the Sosnovskyi hogweed Heracleum sosnowskyi Manden, and food agar (AA). Spherical composite CaAPGPs were obtained from low-methyl esterified AP with a molecular weight of 406 kDa, pectin HS with a molecular weight >300 kDa, and food agar (AA) in the presence of Ca2+ ions (0.34 M) as a cross-linking agent by the method of ionotropic gelation. It was found that dry CaAPGPs based on AP (Ca-AA-AP) have a diameter of 1.16±0.14-1.23±0.05 mm, which was greater than the diameter of dry CaAPGPs based on HS (Ca-AA-HS) (0.95±0.12-1.16±0.05 mm). The density of dry CaAPGPs based on AP (Ca-AA-AP) with an increase in the concentration of AP in their composition from 1% to 2% increased by 1.7 times – from 0.37±0.07 mg/mm3 to 0.63±0.05 mg/mm3. Dry composite CaAPGPs based on HS (Ca-AA-HS) were denser. With an increase in the HS concentration in their composition from 1% to 2%, the degree of particle density increases by 2.2 – from 0.45±0.03 mg/mm3 to 0.97±0.19 mg/mm3. The swelling and degradation of the obtained dry composite CaAPGPs in an artificial gastroenteric environment were studied. It was found that CaAPGPs formed from 1% AP and 2% AA degraded almost immediately in SIF. Whereas, CaAPGPs formed from 2% AP and 1% or 2% AA completely degraded in SCF after 1 hour of incubation in it. CaAPGPs formed from 1% HS and 2% AA, and particles obtained from 2% HS and 1% AA, remained stable in SIF, and then completely degraded immediately upon entering in SCF. CaAPGPs, consisting of 2% HS and 2% AA, dissolve in SCF after 1 hour of incubation in it.

scholarly journals Production, Properties and Swelling of Composite Pectic-Gel Particles in an Artificial Gastric Environment

2021 ◽  
Vol 11 (2) ◽  
pp. 173-176
Author(s):  
Anatoly Shubakov ◽  
Elena Mikhailova
Keyword(s):  
Aqueous Solutions ◽  
Aerial Part ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Apple Pectin ◽  
Ionotropic Gelation ◽  
Heracleum Sosnowskyi ◽  
Gel Particles ◽  
Composite Gel ◽  
Degree Of Swelling

The purpose of the present work was to obtain and study the properties of composite calcium-pectic gel particles (CaPGPs) obtained from aqueous solutions of apple pectin (AP) in the concentration of 2% and pectin heracleuman (HS) in the concentration of 3% in the presence of Ca2+ ions (0.34 M). The swelling of the obtained CaPGPs in an artificial gastric environment was also investigated. Methods and Results: We used commercial AP AU701 (AP, Herbstreith & Fox KG, Germany) and HP isolated from the aerial part of the Sosnovskyi hogweed Heracleum sosnowskyi Manden. Composite CaPGPs were obtained from aqueous solutions of AP (2%) and HS (3%) in the presence of Ca2+ ions (0.34 M) by the method of ionotropic gelation. The diameter and density of CaPGPs were determined. Dry gel particles from 2% AP were larger (1.18±0.19 mm) than dry gel particles from 3% HS (1.04±0.07 mm) and dry composite gel particles (1.01±0.06 mm). However, dry composite gel particles and dry gel particles from HS were approximately 3 times denser than dry gel particles from AP. Composite CaPGPs swelled by 74.2% in simulated gastric fluid (SGF). The degree of swelling in SGF of CaPGPs formed from HS was 15.6% lower, and CaPGPs formed from AP –52.2%.

scholarly journals Production, Properties and Swelling of Copper-Pectic Gel Particles in an Artificial Gastroenteric Environment

2021 ◽  
Vol 11 (1) ◽  
pp. 50-52
Author(s):  
Anatoly Shubakov ◽  
Elena Mikhailova
Keyword(s):  
Aqueous Solutions ◽  
Copper Ions ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Intestinal Fluid ◽  
Apple Pectin ◽  
Simulated Intestinal Fluid ◽  
Ionotropic Gelation ◽  
Gel Particles

The purpose of the this research was to obtain and study the properties of copper-pectic gel particles (CuPGPs) obtained from aqueous solutions of apple pectin (AP) in the concentration range of 1%-5% in the presence of Cu2+ ions. Methods and Results: We used commercial AP AU701 (Herbstreith & Fox KG, Germany). CuPGPs were obtained from aqueous solutions of AP (1%, 3%, 5%) in the presence of Cu2+ ions (1%-10%) by the method of ionotropic gelation, The diameter and density of the CuPGPs were determined. Dry CuPGPs formed from 5% AP with all tested concentrations of copper ions have the largest diameter (0.96-1.15mm), and gel particles formed on the basis of 1% AP have the smallest diameter (0.42-0.74mm). CuPGPs formed from 5% AP have the highest density (1.43-1.65 mg/mm3), and CuPGPs formed on the basis of 1% AP have the lowest density (0.65-0.92 mg/mm3). Gel particles obtained from 1% AP swelled in simulated gastric fluid (SGF) by 161% and then completely degraded immediately upon entering in simulated intestinal fluid (SIF). CuPGPs obtained from 3% AP swelled by 166% in simulated gastric fluid (SGF) and 148% in SIF, and completely degraded in SIF after 2.5 hours of incubation in it. Gel particles obtained from 5% AP in the presence of 10% Cu2+ swelled most strongly – by 173% in SGF and by 208% in SIF. And then, they degraded after 8 hours of incubation in simulated colonic fluid (SCF).

Cross-Linked αsγt-Chain Hybrids in Plasma Clots Studied by 1D- and 2D Electrophoresis and Western Blotting

1993 ◽  
Vol 70 (03) ◽  
pp. 438-442 ◽  
Author(s):  
B Grøn ◽  
C Filion-Myklebust ◽  
S Bjørnsen ◽  
P Haidaris ◽  
F Brosstad
Keyword(s):  
Molecular Weight ◽  
Monoclonal Antibodies ◽  
Human Plasma ◽  
Western Blotting ◽  
Isoelectric Point ◽  
Factor Xiii ◽  
Cross Linking ◽  
2D Electrophoresis ◽  
Complex Phenomenon ◽  
Fibrinopeptide A

SummaryFibrinogen and fibrin related chains in reduced human plasma as well as the bonds interlinking partially cross-linked fibrin from plasma clots have been studied by means of 1D- and 2D electrophoresis and Western blotting. Immunovisualization of reduced plasma or partially cross-linked fibrin with monoclonal antibodies specific for the α-chains or the γ-chains have shown that several bands represent material belonging to both chains. In order to decide whether these bands constitute αγ-chain hybrids or superimposed α- and γ-chain dimers, the cross-linked material was separated according to both isoelectric point (pI) and molecular weight (MW) using Pharmacia’s Multiphor II system. Western blotting of the second dimension gels revealed that partially cross-linked fibrin contains αsγt-chain hybrids and γ- polymers, in addition to the well-known γ-dimers and α-polymers. The main αsγt-chain hybrid has a pI between that of the α- and the γ-chains, a MW of about 200 kDa and contains Aα-chains with intact fibrinopeptide A (FPA). It was also observed that soluble fibrinogen/fibrin complexes as well as partially cross-linked fibrin contain degraded α-dimers with MWs close to the γ-dimers. These findings demonstrate that factor XIII-catalyzed cross-linking of fibrin is a more complex phenomenon than earlier recognized.

Molecular Dynamics Modeling of Polymer Flammability

1992 ◽  
Vol 278 ◽  
Author(s):  
Marc R. Nyden ◽  
James E. Brown ◽  
S. M. Lomakin
Keyword(s):  
Molecular Dynamics ◽  
Molecular Weight ◽  
Cross Linking ◽  
Molecular Dynamic Simulations ◽  
Dynamics Modeling ◽  
Dynamic Simulations ◽  
Char Formation ◽  
Molecular Dynamics Modeling ◽  
Linked Model ◽  
Polymer Flammability

AbstractMolecular dynamic simulations were used to identify factors which promote char formation during the thermal degradation of polymers. Computer movies based on these simulations, indicate that cross-linked model polymers tend to undergo further cross-linking when burned, eventually forming a high molecular weight, thermally stable char. This prediction was confirmed by char yield measurements made on γ and e - irradiated polyethylene and chemically cross-linked poly(methyl methacrylate).

Chemically Designed, UV Curable Polycarbosilane Polymers

1992 ◽  
Vol 271 ◽  
Author(s):  
Kevin J. Thorne ◽  
Stephen E. Johnson ◽  
Haixing Zheng ◽  
John D. Mackenzie ◽  
M. F Hawthorne
Keyword(s):  
Molecular Weight ◽  
Inert Atmosphere ◽  
Uv Exposure ◽  
Cross Linking ◽  
Substitution Reactions ◽  
High Solubility ◽  
Chemical Route ◽  
Uv Curable ◽  
Polymer Precursors ◽  
C Nmr

ABSTRACTTo prepare new polycarbosilane polymer precursors with high solubility and the capability of UV cross-linking, commercial polycarbosilane was modified by a chemical route. These modifications involved AlCl3 catalyzed chlorination reactions of polycarbosilane's Si-H bonds. The resultant Si-Cl bonds were substituted by a reaction with sodium acetylyde to form Si-C=CH ligands. These ligands are suitable for controlled, free radical initiated cross-linking of the polycarbosilane polymers. The increase in molecular weight should allow for increased Tg's and the retention of polymer pre-forms. In this report, the chlorination of the polycarbosilane polymer and the substitution reactions of polycarbosilane were examined with IR, 29Si and 13C NMR spectroscopy. In addition, the retention of polymer pre-forms were analyzed after UV exposure and inert atmosphere pyrolysis.

Sign in / Sign up

Export Citation Format

Share Document