Relationship between molecular weights and biological properties of alginates extracted under different methods from Colpomenia peregrina

For tissue engineering applications, biodegradable scaffolds containing high molecular weights (MW) of collagen and sodium alginate have been developed and characterized. However, the properties of low MW collagen-based scaffolds have not been studied in previous research. This work examined the distinctive properties of low MW collagen-based scaffolds with alginate unmodified and modified by subcritical water. Besides, we developed a facile method to cross-link water-soluble scaffolds using glutaraldehyde in an aqueous ethanol solution. The prepared cross-linked scaffolds showed good structural properties with high porosity (~93%) and high cross-linking degree (50–60%). Compared with collagen (6000 Da)-based scaffolds, collagen (25,000 Da)-based scaffolds exhibited higher stability against collagenase degradation and lower weight loss in phosphate buffer pH 7.4. Collagen (25,000 Da)-based scaffolds with modified alginate tended to improve antioxidant capacity compared with scaffolds containing unmodified alginate. Interestingly, in vitro coagulant activity assay demonstrated that collagen (25,000 Da)-based scaffolds with modified alginate (C25-A63 and C25-A21) significantly reduced the clotting time of human plasma compared with scaffolds consisting of unmodified alginate. Although some further investigations need to be done, collagen (25,000 Da)-based scaffolds with modified alginate should be considered as a potential candidate for tissue engineering applications.

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A Simple Approach to Produce Tailor-Made Chitosans with Specific Degrees of Acetylation and Molecular Weights

Polymers ◽

10.3390/polym13152415 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2415

Author(s):

Luis-Felipe Sánchez ◽

Jimmy Cánepa ◽

Suyeon Kim ◽

Javier Nakamatsu

Keyword(s):

Metal Ion ◽

Gel Permeation Chromatography ◽

Biological Properties ◽

Molecular Weights ◽

Monomer Composition ◽

Ion Absorption ◽

Wide Range ◽

Potential Applications ◽

Different Temperatures ◽

Metal Ion Absorption

Chitin is a structural polysaccharide that is found in crustaceans, insects, fungi and some yeasts. Chitin deacetylation produces chitosan, a well-studied biopolymer with reported chemical and biological properties for diverse potential applications for drug delivery, metal ion absorption, scaffolds and tissue engineering. Most known properties of chitosan have been determined from samples obtained from a variety of sources and in different conditions, this is, from chitosans with a wide range of degrees of N-acetylation (DA) and molecular weight (MW). However, as for any copolymer, the physicochemical and mechanical characteristics of chitosan highly depend on their monomer composition (DA) and chain size (MW). This work presents a simple methodology to produce chitosans with specific and predictive DA and MW. Reaction with acetic anhydride proved to be an efficient method to control the acetylation of chitosan, DAs between 10.6% and 50.6% were reproducibly obtained. In addition to this, MWs of chitosan chains were reduced in a controlled manner in two ways, by ultrasound and by acidic hydrolysis at different temperatures, samples with MWs between 130 kDa and 1300 kDa were obtained. DAs were determined by 1H-NMR and MWs by gel permeation chromatography.

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Evaluation of Acid-Treated Hyaluronic Acid-Based Hydrogelation

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.342-343.745 ◽

2007 ◽

Vol 342-343 ◽

pp. 745-748

Author(s):

Mi Sook Kim ◽

Yoon Jeong Choi ◽

Gun Woo Kim ◽

In Sup Noh ◽

Yong Doo Park ◽

...

Keyword(s):

Molecular Weight ◽

Hyaluronic Acid ◽

Gel Permeation Chromatography ◽

Biological Properties ◽

Cellular Interactions ◽

Molecular Weights ◽

Chemical Structures ◽

Poly Ethylene Oxide ◽

Poly Ethylene

Though hyaluronic acid (HA)-based hydrogel has drawn great attention in biomedical society, it’s long molecular weights sometimes have been problematic due to its difficulty in handling. After reduction of its high molecular weight into smaller sizes with various concentrations of hydrogen chloride solutions, its chemical and biological properties have been examined by changes in viscosity, FTIR spectroscopy and gel permeation chromatography as well as cellular interactions. While FTIR analysis indicated maintenance of its original chemical structures, its viscosity has been remarkably reduced and its extent was dependent upon the employment of acid concentrations. After controlling its molecular weight to approximately 100 kDa and coupling of aminopropymethacrylate to the treated HA, we evaluated in vitro cellular interactions and cell proliferations of the HA-poly(ethylene oxide) (PEO) hydrogel.

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Production, purification, characterization, and biological properties of Rhodosporidium paludigenum polysaccharide

PLoS ONE ◽

10.1371/journal.pone.0246148 ◽

2021 ◽

Vol 16 (1) ◽

pp. e0246148

Author(s):

Mengjian Liu ◽

WenJu Zhang ◽

Jun Yao ◽

Junli Niu

Keyword(s):

Pathogenic Bacteria ◽

Inhibitory Concentration ◽

Biological Properties ◽

Molecular Weights ◽

Fermentation Parameters ◽

Main Components ◽

Image Position ◽

G Ratio

The yield of marine red yeast polysaccharide (MRYP) obtained from Rhodosporidium paludigenum was increased by optimizing fermentation conditions, and the pure polysaccharide was extracted by column chromatography. The molecular weight of pure MRYP and the ratio of mannose to glucose in components of MRYP were determined. Antioxidant and antibacterial abilities of MRYP were investigated in vitro and in vivo. The optimal fermentation parameters were as follows: Medium 4, pH = 6.72, temperature = 30.18°C, blades speed = 461.36 r/min; the optimized yield reached 4323.90 mg/L, which was 1.31 times the original yield. The sequence of factors that affected the MRYP yield was the blades speed>pH>temperature. The main components of MRYP were MYH-1 and MYH-2. The molecular weights of MYH-1 and MYH-2 were 246.92 kDa and 21.88 kDa, respectively; they accounted for 53.60% and 28.75% of total polysaccharide. In MYH-1 and MYH-2, the proportion of glucose and mannose accounted for 46.94%, 38.46%, and 67.10%, 7.17%, respectively. In vitro, the ability of scavenging DPPH•, •OH, and •O2− radical was 32.26%, 24.34%, and 22.09%; the minimum inhibitory concentration (MIC) of MRYP was 480 μg/mg. In vivo, MRYP improved the lambs’ body weight, antioxidant enzyme activity, and the number of probiotics, but it reduced the feed/gain (F/G) ratio and the number of pathogenic bacteria in 60-days-old lambs.

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Chemical properties of guinea-pig immunoglobulins γ2G and γM

Biochemical Journal ◽

10.1042/bj1200787 ◽

1970 ◽

Vol 120 (4) ◽

pp. 787-795 ◽

Cited By ~ 34

Author(s):

R. G. Q. Leslie ◽

S. Cohen

Keyword(s):

Amino Acid ◽

Guinea Pig ◽

Chemical Properties ◽

Biological Properties ◽

Extinction Coefficients ◽

Amino Acid Compositions ◽

Molecular Weights ◽

Structural Differences ◽

Polypeptide Chains

The isolation of guinea-pig immunoglobulins γ1G, γ2G and γM are described and methods for separating the polypeptide chains of each examined. The molecular weights, extinction coefficients and carbohydrate and amino acid compositions of the immunoglobulins and their constituent chains have been analysed. The findings provide a basis for further studies attempting to relate structural differences to distinct biological properties of guinea-pig immunoglobulins.

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Resorbable Polymer Membranes for Medical Applications

Journal of Biomimetics Biomaterials and Tissue Engineering ◽

10.4028/www.scientific.net/jbbte.19.99 ◽

2014 ◽

Vol 19 ◽

pp. 99-108 ◽

Cited By ~ 2

Author(s):

Ewa Stodolak-Zych ◽

Anna Łuszcz ◽

Elżbieta Menaszek ◽

Anna Ścisłowska-Czarencka

Keyword(s):

Molecular Weight ◽

Porous Materials ◽

Conductivity Measurement ◽

Biological Properties ◽

Casting Method ◽

Molecular Weights ◽

Average Porosity ◽

Test Cells ◽

Bioresorbable Polymer

A bioresorbable polymer poly-ε-caprolactone (PCL) was tested in order to obtain porous materials suitable for membranes. The commercial PCL with various molecular weights (2kDa, 60kDa, 80 kDa) but similar polydispersity has been chosen. The membranes were produced by the casting method and the membrane materials underwent microstructure investigation (SEM) to assess the size of pores and an average porosity of the membranes. The membranes permeability was established by means of ultrafiltration. Also wettabilility and basic mechanical properties (such as: tensile strength Rm, Youngs modulus, E) were established. The membranes durability was tested in in vitro conditions (PBS/37°C) by monitoring of changes by means of ion conductivity measurement and changes in the molecular weight (the Ubbelohde method). The porous materials were tested towards biocompatibility, i.e. the membrane was contacted with the osteoblast line of NHOst cells (viability test, cells morphology). Non-perforated PCL foil was used as a reference material. The best physicochemical, mechanical and biological properties of the membranes were observed in case of application of PCL with molecular weight of 60 kDa.

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Integration of Biomechanical and Biological Characterization in the Development of Porous Poly(caprolactone)-Based Membranes for Abdominal Wall Hernia Treatment

International Journal of Polymer Science ◽

10.1155/2018/2450176 ◽

2018 ◽

Vol 2018 ◽

pp. 1-15

Author(s):

Federico Vozzi ◽

Tiziana Nardo ◽

Ilenia Guerrazzi ◽

Claudio Domenici ◽

Silvia Rocchiccioli ◽

...

Keyword(s):

Abdominal Wall ◽

Abdominal Wall Hernia ◽

Biomechanical Properties ◽

Collagen Type I ◽

Porous Membrane ◽

Biological Properties ◽

Type I ◽

Molecular Weights ◽

Intermediate Surface

Aims. Synthetic meshes are the long-standing choice for the clinical treatment of abdominal wall hernias: the associated long-term complications have stimulated the development of a new generation of bioresorbable prostheses. In this work, polycaprolactone (PCL) porous membranes prepared by solvent casting/porogen leaching of PCL/poly(ethylene glycol) (PEG) blends with different compositions (different PCL/PEG weight ratios and PEG molecular weights) were investigated to be applied in the field. An optimal porous membrane structure was selected based on the evaluation of physicochemical, biomechanical, and in vitro biological properties, compared to a reference commercially available hernia mesh (CMC). Findings. Selected PCL7-2i membranes, derived from PCL/PEG 70/30 (PCL: Mw 70,000-90,000 Da; PEG: 35,000 Da), showed suitable pore size for the application, intermediate surface hydrophilicity, and biomimetic mechanical properties. In vitro cell tests performed on PCL7-2i membranes showed their cytocompatibility, high cell growth during 21 days, a reduced production of proinflammatory IL-6 with respect to CMC, and a significant secretion of collagen type I. Conclusions. PCL7-2i membranes showed biomimetic biomechanical properties and in vitro biological properties similar to or even better than - in the case of anti-inflammatory behavior and collagen production - CMC, a commercially available product, suggesting potentially improved integration in the host tissue.

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Transmission Electron Microscopy of Protein Macromolecules

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066176 ◽

1971 ◽

Vol 29 ◽

pp. 424-425

Author(s):

Henry S. Slayter

Keyword(s):

Biological Systems ◽

Metal Vapor ◽

Resolving Power ◽

Electron Microscopic ◽

Chemical Methods ◽

Molecular Weights ◽

The Past ◽

Physical Chemical ◽

Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

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Characterization of microtubules by dark-field STEM and replication

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008506x ◽

1991 ◽

Vol 49 ◽

pp. 152-153

Author(s):

S.B. Andrews ◽

R.D. Leapman ◽

P.E. Gallant ◽

T.S. Reese

Keyword(s):

Protein Interactions ◽

Low Dose ◽

Unit Length ◽

Dark Field ◽

Carbon Films ◽

Microtubule Associated Proteins ◽

Molecular Weights ◽

Freeze Dried ◽

Protein Motors ◽

Associated Proteins

As part of a study on protein interactions involved in microtubule (MT)-based transport, we used the VG HB501 field-emission STEM to obtain low-dose dark-field mass maps of isolated, taxol-stabilized MTs and correlated these micrographs with detailed stereo images from replicas of the same MTs. This approach promises to be useful for determining how protein motors interact with MTs. MTs prepared from bovine and squid brain tubulin were purified and free from microtubule-associated proteins (MAPs). These MTs (0.1-1 mg/ml tubulin) were adsorbed to 3-nm evaporated carbon films supported over Formvar nets on 600-m copper grids. Following adsorption, the grids were washed twice in buffer and then in either distilled water or in isotonic or hypotonic ammonium acetate, blotted, and plunge-frozen in ethane/propane cryogen (ca. -185 C). After cryotransfer into the STEM, specimens were freeze-dried and recooled to ca.-160 C for low-dose (<3000 e/nm2) dark-field mapping. The molecular weights per unit length of MT were determined relative to tobacco mosaic virus standards from elastic scattering intensities. Parallel grids were freeze-dried and rotary shadowed with Pt/C at 14°.

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Electron Microscope Study of RNA's of Paramyxoviruses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100094231 ◽

1972 ◽

Vol 30 ◽

pp. 196-197

Author(s):

Ruchama Baum ◽

J.T. Seto

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Electron Microscope Study ◽

Sendai Virus ◽

Sodium Dodecyl ◽

Rna Molecules ◽

Virus Particles ◽

Molecular Weights ◽

Length Measurements

The ribonucleic acid (RNA) of paramyxoviruses has been characterized by biochemical and physiochemical methods. However, paramyxovirus RNA molecules have not been studied by electron microscopy. The molecular weights of these single-stranded viral RNA molecules are not known as yet. Since electron microscopy has been found to be useful for the characterization of single-stranded RNA, this investigation was initiated to examine the morphology and length measurements of paramyxovirus RNA's.Sendai virus Z strain and Newcastle disease virus (NDV), Milano strain, were used. For these studies it was necessary to develop a method of extracting RNA molecules from purified virus particles. Highly purified Sendai virus was treated with pronase (300 μg/ml) at 37°C for 30 minutes and the RNA extracted by the sodium dodecyl sulfate (SDS)-phenol procedure.

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